view src/os_unix.c @ 34854:97b5457962ed v9.1.0296

patch 9.1.0296: regexp: engines do not handle case-folding well Commit: https://github.com/vim/vim/commit/7a27c108e0509f3255ebdcb6558e896c223e4d23 Author: Christian Brabandt <cb@256bit.org> Date: Tue Apr 9 22:53:19 2024 +0200 patch 9.1.0296: regexp: engines do not handle case-folding well Problem: Regex engines do not handle case-folding well Solution: Correctly calculate byte length of characters to skip When the regexp engine compares two utf-8 codepoints case insensitively it may match an adjacent character, because it assumes it can step over as many bytes as the pattern contains. This however is not necessarily true because of case-folding, a multi-byte UTF-8 character can be considered equal to some single-byte value. Let's consider the pattern '?' and the string 's'. When comparing and ignoring case, the single character 's' matches, and since it matches Vim will try to step over the match (by the amount of bytes of the pattern), assuming that since it matches, the length of both strings is the same. However in that case, it should only step over the single byte value 's' so by 1 byte and try to start matching after it again. So for the backtracking engine we need to ensure: - we try to match the correct length for the pattern and the text - in case of a match, we step over it correctly The same thing can happen for the NFA engine, when skipping to the next character to test for a match. We are skipping over the regstart pointer, however we do not consider the case that because of case-folding we may need to adjust the number of bytes to skip over. So this needs to be adjusted in find_match_text() as well. A related issue turned out, when prog->match_text is actually empty. In that case we should try to find the next match and skip this condition. fixes: #14294 closes: #14433 Signed-off-by: Christian Brabandt <cb@256bit.org>
author Christian Brabandt <cb@256bit.org>
date Tue, 09 Apr 2024 23:00:08 +0200
parents 19e038a1139a
children 286bee19bc96
line wrap: on
line source

/* vi:set ts=8 sts=4 sw=4 noet:
 *
 * VIM - Vi IMproved	by Bram Moolenaar
 *	      OS/2 port by Paul Slootman
 *	      VMS merge by Zoltan Arpadffy
 *
 * Do ":help uganda"  in Vim to read copying and usage conditions.
 * Do ":help credits" in Vim to see a list of people who contributed.
 * See README.txt for an overview of the Vim source code.
 */

/*
 * os_unix.c -- code for all flavors of Unix (BSD, SYSV, SVR4, POSIX, ...)
 *	     Also for OS/2, using the excellent EMX package!!!
 *	     Also for Atari MiNT.
 *
 * A lot of this file was originally written by Juergen Weigert and later
 * changed beyond recognition.
 */

#include "vim.h"

#ifdef FEAT_MZSCHEME
# include "if_mzsch.h"
#endif

#include "os_unixx.h"	    // unix includes for os_unix.c only

#ifdef USE_XSMP
# include <X11/SM/SMlib.h>
#endif

#ifdef HAVE_SELINUX
# include <selinux/selinux.h>
static int selinux_enabled = -1;
#endif

#ifdef FEAT_XATTR
# include <sys/xattr.h>
#endif

#ifdef HAVE_SMACK
# include <sys/xattr.h>
# include <linux/xattr.h>
# ifndef SMACK_LABEL_LEN
#  define SMACK_LABEL_LEN 1024
# endif
#endif

#ifdef __CYGWIN__
# include <cygwin/version.h>
# include <sys/cygwin.h>	// for cygwin_conv_to_posix_path() and/or
				// for cygwin_conv_path()
# ifdef FEAT_CYGWIN_WIN32_CLIPBOARD
#  define WIN32_LEAN_AND_MEAN
#  include <windows.h>
#  include "winclip.pro"
# endif
#endif

#ifdef FEAT_MOUSE_GPM

# include <gpm.h>

# ifdef DYNAMIC_GPM
#  define Gpm_Open     (*dll_Gpm_Open)
#  define Gpm_Close    (*dll_Gpm_Close)
#  define Gpm_GetEvent (*dll_Gpm_GetEvent)
#  define gpm_flag     (dll_gpm_flag != NULL ? *dll_gpm_flag :  0)
#  define gpm_fd       (dll_gpm_fd   != NULL ? *dll_gpm_fd   : -1)

static int (*dll_Gpm_Open)     (Gpm_Connect *, int);
static int (*dll_Gpm_Close)    (void);
static int (*dll_Gpm_GetEvent) (Gpm_Event *);
static int *dll_gpm_flag;
static int *dll_gpm_fd;

static void *libgpm_hinst;
# endif

// <linux/keyboard.h> contains defines conflicting with "keymap.h",
// I just copied relevant defines here. A cleaner solution would be to put gpm
// code into separate file and include there linux/keyboard.h
// #include <linux/keyboard.h>
# define KG_SHIFT	0
# define KG_CTRL	2
# define KG_ALT		3
# define KG_ALTGR	1
# define KG_SHIFTL	4
# define KG_SHIFTR	5
# define KG_CTRLL	6
# define KG_CTRLR	7
# define KG_CAPSSHIFT	8

static void gpm_close(void);
static int gpm_open(void);
static int mch_gpm_process(void);
#endif

#ifdef FEAT_SYSMOUSE
# include <sys/consio.h>
# include <sys/fbio.h>

static int sysmouse_open(void);
static void sysmouse_close(void);
static void sig_sysmouse SIGPROTOARG;
#endif

/*
 * end of autoconf section. To be extended...
 */

// Are the following #ifdefs still required? And why? Is that for X11?

#if defined(ESIX) || defined(M_UNIX) && !defined(SCO)
# ifdef SIGWINCH
#  undef SIGWINCH
# endif
# ifdef TIOCGWINSZ
#  undef TIOCGWINSZ
# endif
#endif

#if defined(SIGWINDOW) && !defined(SIGWINCH)	// hpux 9.01 has it
# define SIGWINCH SIGWINDOW
#endif

#ifdef FEAT_X11
# include <X11/Xlib.h>
# include <X11/Xutil.h>
# include <X11/Xatom.h>
# ifdef FEAT_XCLIPBOARD
#  include <X11/Intrinsic.h>
#  include <X11/Shell.h>
#  include <X11/StringDefs.h>
static Widget	xterm_Shell = (Widget)0;
static void clip_update(void);
static void xterm_update(void);
# endif

Window	    x11_window = 0;
Display	    *x11_display = NULL;
#endif

static int ignore_sigtstp = FALSE;

static int get_x11_title(int);

static char_u	*oldtitle = NULL;
static volatile sig_atomic_t oldtitle_outdated = FALSE;
static int	unix_did_set_title = FALSE;
static char_u	*oldicon = NULL;
static int	did_set_icon = FALSE;

static void may_core_dump(void);

#ifdef HAVE_UNION_WAIT
typedef union wait waitstatus;
#else
typedef int waitstatus;
#endif
static int  WaitForChar(long msec, int *interrupted, int ignore_input);
static int  WaitForCharOrMouse(long msec, int *interrupted, int ignore_input);
#ifdef VMS
int  RealWaitForChar(int, long, int *, int *interrupted);
#else
static int  RealWaitForChar(int, long, int *, int *interrupted);
#endif

#ifdef FEAT_XCLIPBOARD
static int do_xterm_trace(void);
# define XT_TRACE_DELAY	50	// delay for xterm tracing
#endif

static void handle_resize(void);

#if defined(SIGWINCH)
static void sig_winch SIGPROTOARG;
#endif
#if defined(SIGTSTP)
static void sig_tstp SIGPROTOARG;
// volatile because it is used in signal handler sig_tstp() and
// sigcont_handler().
static volatile sig_atomic_t in_mch_suspend = FALSE;
#endif
#if defined(SIGINT)
static void catch_sigint SIGPROTOARG;
#endif
#if defined(SIGUSR1)
static void catch_sigusr1 SIGPROTOARG;
#endif
#if defined(SIGPWR)
static void catch_sigpwr SIGPROTOARG;
#endif
#if defined(SIGALRM) && defined(FEAT_X11) && !defined(FEAT_GUI_GTK)
# define SET_SIG_ALARM
static void sig_alarm SIGPROTOARG;
// volatile because it is used in signal handler sig_alarm().
static volatile sig_atomic_t sig_alarm_called;
#endif
static void deathtrap SIGPROTOARG;

static void catch_int_signal(void);
static void set_signals(void);
static void catch_signals(void (*func_deadly)(int), void (*func_other)(int));
#ifdef HAVE_SIGPROCMASK
# define SIGSET_DECL(set)	sigset_t set;
# define BLOCK_SIGNALS(set)	block_signals(set)
# define UNBLOCK_SIGNALS(set)	unblock_signals(set)
#else
# define SIGSET_DECL(set)
# define BLOCK_SIGNALS(set)	do { /**/ } while (0)
# define UNBLOCK_SIGNALS(set)	do { /**/ } while (0)
#endif
static int  have_wildcard(int, char_u **);
static int  have_dollars(int, char_u **);

static int save_patterns(int num_pat, char_u **pat, int *num_file, char_u ***file);

#ifndef SIG_ERR
# define SIG_ERR	((sighandler_T)-1)
#endif
#ifndef SIG_HOLD
# define SIG_HOLD	((sighandler_T)-2)
#endif

// volatile because it is used in signal handler sig_winch().
static volatile sig_atomic_t do_resize = FALSE;
// volatile because it is used in signal handler sig_tstp().
static volatile sig_atomic_t got_tstp = FALSE;
static char_u	*extra_shell_arg = NULL;
static int	show_shell_mess = TRUE;
// volatile because it is used in signal handler deathtrap().
static volatile sig_atomic_t deadly_signal = 0;	   // The signal we caught
// volatile because it is used in signal handler deathtrap().
static volatile sig_atomic_t in_mch_delay = FALSE; // sleeping in mch_delay()

#if defined(FEAT_JOB_CHANNEL) && !defined(USE_SYSTEM)
static int dont_check_job_ended = 0;
#endif

// Current terminal mode from mch_settmode().  Can differ from cur_tmode.
static tmode_T mch_cur_tmode = TMODE_COOK;

#ifdef USE_XSMP
typedef struct
{
    SmcConn smcconn;	    // The SM connection ID
    IceConn iceconn;	    // The ICE connection ID
    char *clientid;	    // The client ID for the current smc session
    Bool save_yourself;     // If we're in the middle of a save_yourself
    Bool shutdown;	    // If we're in shutdown mode
} xsmp_config_T;

static xsmp_config_T xsmp;
#endif

#ifdef SYS_SIGLIST_DECLARED
/*
 * I have seen
 *  extern char *_sys_siglist[NSIG];
 * on Linux, NetBSD and Solaris. It contains a nice list of strings
 * that describe the signals. That is nearly what we want here.  But
 * autoconf does only check for sys_siglist (without the underscore), I
 * do not want to change everything today.... jw.
 * This is why AC_DECL_SYS_SIGLIST is commented out in configure.ac.
 */
#endif

static struct signalinfo
{
    int	    sig;	// Signal number, eg. SIGSEGV etc
    char    *name;	// Signal name (not char_u!).
    char    deadly;	// Catch as a deadly signal?
} signal_info[] =
{
#ifdef SIGHUP
    {SIGHUP,	    "HUP",	TRUE},
#endif
#ifdef SIGQUIT
    {SIGQUIT,	    "QUIT",	TRUE},
#endif
#ifdef SIGILL
    {SIGILL,	    "ILL",	TRUE},
#endif
#ifdef SIGTRAP
    {SIGTRAP,	    "TRAP",	TRUE},
#endif
#ifdef SIGABRT
    {SIGABRT,	    "ABRT",	TRUE},
#endif
#ifdef SIGEMT
    {SIGEMT,	    "EMT",	TRUE},
#endif
#ifdef SIGFPE
    {SIGFPE,	    "FPE",	TRUE},
#endif
#ifdef SIGBUS
    {SIGBUS,	    "BUS",	TRUE},
#endif
#if defined(SIGSEGV) && !defined(FEAT_MZSCHEME)
    // MzScheme uses SEGV in its garbage collector
    {SIGSEGV,	    "SEGV",	TRUE},
#endif
#ifdef SIGSYS
    {SIGSYS,	    "SYS",	TRUE},
#endif
#ifdef SIGALRM
    {SIGALRM,	    "ALRM",	FALSE},	// Perl's alarm() can trigger it
#endif
#ifdef SIGTERM
    {SIGTERM,	    "TERM",	TRUE},
#endif
#if defined(SIGVTALRM) && !defined(FEAT_RUBY)
    {SIGVTALRM,	    "VTALRM",	TRUE},
#endif
#if defined(SIGPROF) && !defined(FEAT_MZSCHEME) && !defined(WE_ARE_PROFILING)
    // MzScheme uses SIGPROF for its own needs; On Linux with profiling
    // this makes Vim exit.  WE_ARE_PROFILING is defined in Makefile.
    {SIGPROF,	    "PROF",	TRUE},
#endif
#ifdef SIGXCPU
    {SIGXCPU,	    "XCPU",	TRUE},
#endif
#ifdef SIGXFSZ
    {SIGXFSZ,	    "XFSZ",	TRUE},
#endif
#ifdef SIGUSR1
    {SIGUSR1,	    "USR1",	FALSE},
#endif
#if defined(SIGUSR2) && !defined(FEAT_SYSMOUSE)
    // Used for sysmouse handling
    {SIGUSR2,	    "USR2",	TRUE},
#endif
#ifdef SIGINT
    {SIGINT,	    "INT",	FALSE},
#endif
#ifdef SIGWINCH
    {SIGWINCH,	    "WINCH",	FALSE},
#endif
#ifdef SIGTSTP
    {SIGTSTP,	    "TSTP",	FALSE},
#endif
#ifdef SIGPIPE
    {SIGPIPE,	    "PIPE",	FALSE},
#endif
    {-1,	    "Unknown!", FALSE}
};

    sighandler_T
mch_signal(int sig, sighandler_T func)
{
#if defined(HAVE_SIGACTION) && defined(HAVE_SIGPROCMASK)
    // Modern implementation: use sigaction().
    struct sigaction	sa, old;
    sigset_t		curset;
    int			blocked;

    if (sigprocmask(SIG_BLOCK, NULL, &curset) == -1)
	return SIG_ERR;

    blocked = sigismember(&curset, sig);

    if (func == SIG_HOLD)
    {
	if (blocked)
	    return SIG_HOLD;

	sigemptyset(&curset);
	sigaddset(&curset, sig);

	if (sigaction(sig, NULL, &old) == -1
				|| sigprocmask(SIG_BLOCK, &curset, NULL) == -1)
	    return SIG_ERR;
	return old.sa_handler;
    }

    if (blocked)
    {
	sigemptyset(&curset);
	sigaddset(&curset, sig);

	if (sigprocmask(SIG_UNBLOCK, &curset, NULL) == -1)
	    return SIG_ERR;
    }

    sa.sa_handler = func;
    sigemptyset(&sa.sa_mask);
# ifdef SA_RESTART
    sa.sa_flags = SA_RESTART;
# else
    sa.sa_flags = 0;
# endif
    if (sigaction(sig, &sa, &old) == -1)
	return SIG_ERR;
    return blocked ? SIG_HOLD: old.sa_handler;
#elif defined(HAVE_SIGSET)
    // Using sigset() is preferred above signal().
    return sigset(sig, func);
#else
    // Oldest and most compatible solution.
    return signal(sig, func);
#endif
}

    int
mch_chdir(char *path)
{
    if (p_verbose >= 5)
    {
	verbose_enter();
	smsg("chdir(%s)", path);
	verbose_leave();
    }
#ifdef VMS
    return chdir(vms_fixfilename(path));
#else
    return chdir(path);
#endif
}

// Why is NeXT excluded here (and not in os_unixx.h)?
#if defined(ECHOE) && defined(ICANON) \
    && (defined(HAVE_TERMIO_H) || defined(HAVE_TERMIOS_H)) \
    && !defined(__NeXT__)
# define NEW_TTY_SYSTEM
#endif

/*
 * Write s[len] to the screen (stdout).
 */
    void
mch_write(char_u *s, int len)
{
    vim_ignored = (int)write(1, (char *)s, len);
    if (p_wd)		// Unix is too fast, slow down a bit more
	RealWaitForChar(read_cmd_fd, p_wd, NULL, NULL);
}

/*
 * Function passed to inchar_loop() to handle window resizing.
 * If "check_only" is TRUE: Return whether there was a resize.
 * If "check_only" is FALSE: Deal with the window resized.
 */
    static int
resize_func(int check_only)
{
    if (check_only)
	return do_resize;
    while (do_resize)
    {
#ifdef FEAT_EVAL
	ch_log(NULL, "calling handle_resize() in resize_func()");
#endif
	handle_resize();
    }
    return FALSE;
}

/*
 * mch_inchar(): low level input function.
 * Get a characters from the keyboard.
 * Return the number of characters that are available.
 * If wtime == 0 do not wait for characters.
 * If wtime == n wait a short time for characters.
 * If wtime == -1 wait forever for characters.
 */
    int
mch_inchar(
    char_u	*buf,
    int		maxlen,
    long	wtime,	    // don't use "time", MIPS cannot handle it
    int		tb_change_cnt)
{
    return inchar_loop(buf, maxlen, wtime, tb_change_cnt,
		       WaitForChar, resize_func);
}

    static void
handle_resize(void)
{
    do_resize = FALSE;
    shell_resized();
}

/*
 * Return non-zero if a character is available.
 */
    int
mch_char_avail(void)
{
    return WaitForChar(0L, NULL, FALSE);
}

#if defined(FEAT_TERMINAL) || defined(PROTO)
/*
 * Check for any pending input or messages.
 */
    int
mch_check_messages(void)
{
    return WaitForChar(0L, NULL, TRUE);
}
#endif

#if defined(HAVE_TOTAL_MEM) || defined(PROTO)
# ifdef HAVE_SYS_RESOURCE_H
#  include <sys/resource.h>
# endif
# if defined(HAVE_SYS_SYSCTL_H) && defined(HAVE_SYSCTL)
#  include <sys/sysctl.h>
# endif
# if defined(HAVE_SYS_SYSINFO_H) && defined(HAVE_SYSINFO)
#  include <sys/sysinfo.h>
# endif
# ifdef MACOS_X
#  include <mach/mach_host.h>
#  include <mach/mach_port.h>
# endif

/*
 * Return total amount of memory available in Kbyte.
 * Doesn't change when memory has been allocated.
 */
    long_u
mch_total_mem(int special UNUSED)
{
    long_u	mem = 0;
    long_u	shiftright = 10;  // how much to shift "mem" right for Kbyte

# ifdef MACOS_X
    {
	// Mac (Darwin) way of getting the amount of RAM available
	mach_port_t		host = mach_host_self();
	kern_return_t		kret;
#  ifdef HOST_VM_INFO64
	struct vm_statistics64	vm_stat;
	natural_t		count = HOST_VM_INFO64_COUNT;

	kret = host_statistics64(host, HOST_VM_INFO64,
					     (host_info64_t)&vm_stat, &count);
#  else
	struct vm_statistics	vm_stat;
	natural_t		count = HOST_VM_INFO_COUNT;

	kret = host_statistics(host, HOST_VM_INFO,
					       (host_info_t)&vm_stat, &count);
#  endif
	if (kret == KERN_SUCCESS)
	    // get the amount of user memory by summing each usage
	    mem = (long_u)(vm_stat.free_count + vm_stat.active_count
					    + vm_stat.inactive_count
#  ifdef MAC_OS_X_VERSION_10_9
					    + vm_stat.compressor_page_count
#  endif
					    ) * sysconf(_SC_PAGESIZE);
	mach_port_deallocate(mach_task_self(), host);
    }
# endif

# ifdef HAVE_SYSCTL
    if (mem == 0)
    {
	// BSD way of getting the amount of RAM available.
	int		mib[2];
	size_t		len = sizeof(long_u);
#  ifdef HW_USERMEM64
	long_u		physmem;
#  else
	// sysctl() may return 32 bit or 64 bit, accept both
	union {
	    int_u	u32;
	    long_u	u64;
	} physmem;
#  endif

	mib[0] = CTL_HW;
#  ifdef HW_USERMEM64
	mib[1] = HW_USERMEM64;
#  else
	mib[1] = HW_USERMEM;
#  endif
	if (sysctl(mib, 2, &physmem, &len, NULL, 0) == 0)
	{
#  ifdef HW_USERMEM64
	    mem = (long_u)physmem;
#  else
	    if (len == sizeof(physmem.u64))
		mem = (long_u)physmem.u64;
	    else
		mem = (long_u)physmem.u32;
#  endif
	}
    }
# endif

# if defined(HAVE_SYS_SYSINFO_H) && defined(HAVE_SYSINFO)
    if (mem == 0)
    {
	struct sysinfo sinfo;

	// Linux way of getting amount of RAM available
	if (sysinfo(&sinfo) == 0)
	{
#  ifdef HAVE_SYSINFO_MEM_UNIT
	    // avoid overflow as much as possible
	    while (shiftright > 0 && (sinfo.mem_unit & 1) == 0)
	    {
		sinfo.mem_unit = sinfo.mem_unit >> 1;
		--shiftright;
	    }
	    mem = sinfo.totalram * sinfo.mem_unit;
#  else
	    mem = sinfo.totalram;
#  endif
	}
    }
# endif

# ifdef HAVE_SYSCONF
    if (mem == 0)
    {
	long	    pagesize, pagecount;

	// Solaris way of getting amount of RAM available
	pagesize = sysconf(_SC_PAGESIZE);
	pagecount = sysconf(_SC_PHYS_PAGES);
	if (pagesize > 0 && pagecount > 0)
	{
	    // avoid overflow as much as possible
	    while (shiftright > 0 && (pagesize & 1) == 0)
	    {
		pagesize = (long_u)pagesize >> 1;
		--shiftright;
	    }
	    mem = (long_u)pagesize * pagecount;
	}
    }
# endif

    // Return the minimum of the physical memory and the user limit, because
    // using more than the user limit may cause Vim to be terminated.
# if defined(HAVE_SYS_RESOURCE_H) && defined(HAVE_GETRLIMIT)
    {
	struct rlimit	rlp;

	if (getrlimit(RLIMIT_DATA, &rlp) == 0
		&& rlp.rlim_cur < ((rlim_t)1 << (sizeof(long_u) * 8 - 1))
#  ifdef RLIM_INFINITY
		&& rlp.rlim_cur != RLIM_INFINITY
#  endif
		&& ((long_u)rlp.rlim_cur >> 10) < (mem >> shiftright)
	   )
	{
	    mem = (long_u)rlp.rlim_cur;
	    shiftright = 10;
	}
    }
# endif

    if (mem > 0)
	return mem >> shiftright;
    return (long_u)0x1fffff;
}
#endif

/*
 * "flags": MCH_DELAY_IGNOREINPUT - don't read input
 *	    MCH_DELAY_SETTMODE - use settmode() even for short delays
 */
    void
mch_delay(long msec, int flags)
{
    tmode_T	old_tmode;
    int		call_settmode;
#ifdef FEAT_MZSCHEME
    long	total = msec; // remember original value
#endif

    if (flags & MCH_DELAY_IGNOREINPUT)
    {
	// Go to cooked mode without echo, to allow SIGINT interrupting us
	// here.  But we don't want QUIT to kill us (CTRL-\ used in a
	// shell may produce SIGQUIT).
	// Only do this if sleeping for more than half a second.
	in_mch_delay = TRUE;
	call_settmode = mch_cur_tmode == TMODE_RAW
			       && (msec > 500 || (flags & MCH_DELAY_SETTMODE));
	if (call_settmode)
	{
	    old_tmode = mch_cur_tmode;
	    settmode(TMODE_SLEEP);
	}

	/*
	 * Everybody sleeps in a different way...
	 * Prefer nanosleep(), some versions of usleep() can only sleep up to
	 * one second.
	 */
#ifdef FEAT_MZSCHEME
	do
	{
	    // if total is large enough, wait by portions in p_mzq
	    if (total > p_mzq)
		msec = p_mzq;
	    else
		msec = total;
	    total -= msec;
#endif
#ifdef HAVE_NANOSLEEP
	{
	    struct timespec ts;

	    ts.tv_sec = msec / 1000;
	    ts.tv_nsec = (msec % 1000) * 1000000;
	    (void)nanosleep(&ts, NULL);
	}
#else
# ifdef HAVE_USLEEP
	while (msec >= 1000)
	{
	    usleep((unsigned int)(999 * 1000));
	    msec -= 999;
	}
	usleep((unsigned int)(msec * 1000));
# else
#  ifndef HAVE_SELECT
	poll(NULL, 0, (int)msec);
#  else
	{
	    struct timeval tv;

	    tv.tv_sec = msec / 1000;
	    tv.tv_usec = (msec % 1000) * 1000;
	    // NOTE: Solaris 2.6 has a bug that makes select() hang here.  Get
	    // a patch from Sun to fix this.  Reported by Gunnar Pedersen.
	    select(0, NULL, NULL, NULL, &tv);
	}
#  endif
# endif
#endif
#ifdef FEAT_MZSCHEME
	}
	while (total > 0);
#endif

	if (call_settmode)
	    settmode(old_tmode);
	in_mch_delay = FALSE;
    }
    else
	WaitForChar(msec, NULL, FALSE);
}

#if defined(HAVE_STACK_LIMIT) \
	|| (!defined(HAVE_SIGALTSTACK) && defined(HAVE_SIGSTACK))
# define HAVE_CHECK_STACK_GROWTH
/*
 * Support for checking for an almost-out-of-stack-space situation.
 */

/*
 * Return a pointer to an item on the stack.  Used to find out if the stack
 * grows up or down.
 */
static int stack_grows_downwards;

/*
 * Find out if the stack grows upwards or downwards.
 * "p" points to a variable on the stack of the caller.
 */
    static void
check_stack_growth(char *p)
{
    int		i;

    stack_grows_downwards = (p > (char *)&i);
}
#endif

#if defined(HAVE_STACK_LIMIT) || defined(PROTO)
static char *stack_limit = NULL;

#if defined(_THREAD_SAFE) && defined(HAVE_PTHREAD_NP_H)
# include <pthread.h>
# include <pthread_np.h>
#endif

/*
 * Find out until how var the stack can grow without getting into trouble.
 * Called when starting up and when switching to the signal stack in
 * deathtrap().
 */
    static void
get_stack_limit(void)
{
    struct rlimit	rlp;
    int			i;
    long		lim;

    // Set the stack limit to 15/16 of the allowable size.  Skip this when the
    // limit doesn't fit in a long (rlim_cur might be "long long").
    if (getrlimit(RLIMIT_STACK, &rlp) == 0
	    && rlp.rlim_cur < ((rlim_t)1 << (sizeof(long_u) * 8 - 1))
#  ifdef RLIM_INFINITY
	    && rlp.rlim_cur != RLIM_INFINITY
#  endif
       )
    {
	lim = (long)rlp.rlim_cur;
#if defined(_THREAD_SAFE) && defined(HAVE_PTHREAD_NP_H)
	{
	    pthread_attr_t  attr;
	    size_t	    size;

	    // On FreeBSD the initial thread always has a fixed stack size, no
	    // matter what the limits are set to.  Normally it's 1 Mbyte.
	    pthread_attr_init(&attr);
	    if (pthread_attr_get_np(pthread_self(), &attr) == 0)
	    {
		pthread_attr_getstacksize(&attr, &size);
		if (lim > (long)size)
		    lim = (long)size;
	    }
	    pthread_attr_destroy(&attr);
	}
#endif
	if (stack_grows_downwards)
	{
	    stack_limit = (char *)((long)&i - (lim / 16L * 15L));
	    if (stack_limit >= (char *)&i)
		// overflow, set to 1/16 of current stack position
		stack_limit = (char *)((long)&i / 16L);
	}
	else
	{
	    stack_limit = (char *)((long)&i + (lim / 16L * 15L));
	    if (stack_limit <= (char *)&i)
		stack_limit = NULL;	// overflow
	}
    }
}

/*
 * Return FAIL when running out of stack space.
 * "p" must point to any variable local to the caller that's on the stack.
 */
    int
mch_stackcheck(char *p)
{
    if (stack_limit == NULL)
	return OK;

    if (stack_grows_downwards)
    {
	if (p < stack_limit)
	    return FAIL;
    }
    else if (p > stack_limit)
	return FAIL;
    return OK;
}
#endif

#if defined(HAVE_SIGALTSTACK) || defined(HAVE_SIGSTACK)
/*
 * Support for using the signal stack.
 * This helps when we run out of stack space, which causes a SIGSEGV.  The
 * signal handler then must run on another stack, since the normal stack is
 * completely full.
 */

# ifdef HAVE_SIGALTSTACK
static stack_t sigstk;			// for sigaltstack()
# else
static struct sigstack sigstk;		// for sigstack()
# endif

/*
 * Get a size of signal stack.
 * Preference (if available): sysconf > SIGSTKSZ > guessed size
 */
static long int get_signal_stack_size(void)
{
# ifdef HAVE_SYSCONF_SIGSTKSZ
    long int size = -1;

    // return size only if sysconf doesn't return an error
    if ((size = sysconf(_SC_SIGSTKSZ)) > -1)
	return size;
# endif

# ifdef SIGSTKSZ
    // if sysconf() isn't available or gives error, return SIGSTKSZ
    // if defined
    return SIGSTKSZ;
# endif

    // otherwise guess the size
    return 8000;
}

static char *signal_stack;

    static void
init_signal_stack(void)
{
    if (signal_stack == NULL)
	return;

# ifdef HAVE_SIGALTSTACK
#  ifdef HAVE_SS_BASE
    sigstk.ss_base = signal_stack;
#  else
    sigstk.ss_sp = signal_stack;
#  endif
    sigstk.ss_size = get_signal_stack_size();
    sigstk.ss_flags = 0;
    (void)sigaltstack(&sigstk, NULL);
# else
    sigstk.ss_sp = signal_stack;
    if (stack_grows_downwards)
	sigstk.ss_sp += get_signal_stack_size() - 1;
    sigstk.ss_onstack = 0;
    (void)sigstack(&sigstk, NULL);
# endif
}
#endif

/*
 * We need correct prototypes for a signal function, otherwise mean compilers
 * will barf when the second argument to signal() is ``wrong''.
 * Let me try it with a few tricky defines from my own osdef.h	(jw).
 */
#if defined(SIGWINCH)
    static void
sig_winch SIGDEFARG(sigarg)
{
    // this is not required on all systems, but it doesn't hurt anybody
    mch_signal(SIGWINCH, sig_winch);
    do_resize = TRUE;
}
#endif

#if defined(SIGTSTP)
    static void
sig_tstp SIGDEFARG(sigarg)
{
    // Second time we get called we actually need to suspend
    if (in_mch_suspend)
    {
	mch_signal(SIGTSTP, ignore_sigtstp ? SIG_IGN : SIG_DFL);
	raise(sigarg);
    }
    else
	got_tstp = TRUE;

#if !defined(__ANDROID__) && !defined(__OpenBSD__) && !defined(__DragonFly__)
    // This is not required on all systems.  On some systems (at least Android,
    // OpenBSD, and DragonFlyBSD) this breaks suspending with CTRL-Z.
    mch_signal(SIGTSTP, sig_tstp);
#endif
}
#endif

#if defined(SIGINT)
    static void
catch_sigint SIGDEFARG(sigarg)
{
    // this is not required on all systems, but it doesn't hurt anybody
    mch_signal(SIGINT, catch_sigint);
    got_int = TRUE;
}
#endif

#if defined(SIGUSR1)
    static void
catch_sigusr1 SIGDEFARG(sigarg)
{
    // this is not required on all systems, but it doesn't hurt anybody
    mch_signal(SIGUSR1, catch_sigusr1);
    got_sigusr1 = TRUE;
}
#endif

#if defined(SIGPWR)
    static void
catch_sigpwr SIGDEFARG(sigarg)
{
    // this is not required on all systems, but it doesn't hurt anybody
    mch_signal(SIGPWR, catch_sigpwr);
    /*
     * I'm not sure we get the SIGPWR signal when the system is really going
     * down or when the batteries are almost empty.  Just preserve the swap
     * files and don't exit, that can't do any harm.
     */
    ml_sync_all(FALSE, FALSE);
}
#endif

#ifdef SET_SIG_ALARM
/*
 * signal function for alarm().
 */
    static void
sig_alarm SIGDEFARG(sigarg)
{
    // doesn't do anything, just to break a system call
    sig_alarm_called = TRUE;
}
#endif

#if (defined(HAVE_SETJMP_H) \
	&& ((defined(FEAT_X11) && defined(FEAT_XCLIPBOARD)) \
	    || defined(FEAT_LIBCALL))) \
    || defined(PROTO)
# define USING_SETJMP 1

// argument to SETJMP()
static JMP_BUF lc_jump_env;

# ifdef SIGHASARG
// Caught signal number, 0 when no signal was caught; used for mch_libcall().
// Volatile because it is used in signal handlers.
static volatile sig_atomic_t lc_signal;
# endif

// TRUE when lc_jump_env is valid.
// Volatile because it is used in signal handler deathtrap().
static volatile sig_atomic_t lc_active = FALSE;

/*
 * A simplistic version of setjmp() that only allows one level of using.
 * Used to protect areas where we could crash.
 * Don't call twice before calling mch_endjmp()!.
 *
 * Usage:
 *	mch_startjmp();
 *	if (SETJMP(lc_jump_env) != 0)
 *	{
 *	    mch_didjmp();
 *	    emsg("crash!");
 *	}
 *	else
 *	{
 *	    do_the_work;
 *	    mch_endjmp();
 *	}
 * Note: Can't move SETJMP() here, because a function calling setjmp() must
 * not return before the saved environment is used.
 * Returns OK for normal return, FAIL when the protected code caused a
 * problem and LONGJMP() was used.
 */
    static void
mch_startjmp(void)
{
# ifdef SIGHASARG
    lc_signal = 0;
# endif
    lc_active = TRUE;
}

    static void
mch_endjmp(void)
{
    lc_active = FALSE;
}

    static void
mch_didjmp(void)
{
# if defined(HAVE_SIGALTSTACK) || defined(HAVE_SIGSTACK)
    // On FreeBSD the signal stack has to be reset after using siglongjmp(),
    // otherwise catching the signal only works once.
    init_signal_stack();
# endif
}
#endif

/*
 * This function handles deadly signals.
 * It tries to preserve any swap files and exit properly.
 * (partly from Elvis).
 * NOTE: Avoid unsafe functions, such as allocating memory, they can result in
 * a deadlock.
 */
    static void
deathtrap SIGDEFARG(sigarg)
{
    static int	entered = 0;	    // count the number of times we got here.
				    // Note: when memory has been corrupted
				    // this may get an arbitrary value!
#ifdef SIGHASARG
    int		i;
#endif

#if defined(USING_SETJMP)
    /*
     * Catch a crash in protected code.
     * Restores the environment saved in lc_jump_env, which looks like
     * SETJMP() returns 1.
     */
    if (lc_active)
    {
# if defined(SIGHASARG)
	lc_signal = sigarg;
# endif
	lc_active = FALSE;	// don't jump again
	LONGJMP(lc_jump_env, 1);
	// NOTREACHED
    }
#endif

#ifdef SIGHASARG
# ifdef SIGQUIT
    // While in mch_delay() we go to cooked mode to allow a CTRL-C to
    // interrupt us.  But in cooked mode we may also get SIGQUIT, e.g., when
    // pressing CTRL-\, but we don't want Vim to exit then.
    if (in_mch_delay && sigarg == SIGQUIT)
	return;
# endif

    // When SIGHUP, SIGQUIT, etc. are blocked: postpone the effect and return
    // here.  This avoids that a non-reentrant function is interrupted, e.g.,
    // free().  Calling free() again may then cause a crash.
    if (entered == 0
	    && (0
# ifdef SIGHUP
		|| sigarg == SIGHUP
# endif
# ifdef SIGQUIT
		|| sigarg == SIGQUIT
# endif
# ifdef SIGTERM
		|| sigarg == SIGTERM
# endif
# ifdef SIGPWR
		|| sigarg == SIGPWR
# endif
# ifdef SIGUSR1
		|| sigarg == SIGUSR1
# endif
# ifdef SIGUSR2
		|| sigarg == SIGUSR2
# endif
		)
	    && !vim_handle_signal(sigarg))
	return;
#endif

    // Remember how often we have been called.
    ++entered;

    // Executing autocommands is likely to use more stack space than we have
    // available in the signal stack.
    block_autocmds();

#ifdef FEAT_EVAL
    // Set the v:dying variable.
    set_vim_var_nr(VV_DYING, (long)entered);
#endif
    v_dying = entered;

#ifdef HAVE_STACK_LIMIT
    // Since we are now using the signal stack, need to reset the stack
    // limit.  Otherwise using a regexp will fail.
    get_stack_limit();
#endif

#if 0
    // This is for opening gdb the moment Vim crashes.
    // You need to manually adjust the file name and Vim executable name.
    // Suggested by SungHyun Nam.
    {
# define VI_GDB_FILE "/tmp/vimgdb"
# define VIM_NAME "/usr/bin/vim"
	FILE *fp = fopen(VI_GDB_FILE, "w");
	if (fp)
	{
	    fprintf(fp,
		    "file %s\n"
		    "attach %d\n"
		    "set height 1000\n"
		    "bt full\n"
		    , VIM_NAME, getpid());
	    fclose(fp);
	    system("xterm -e gdb -x "VI_GDB_FILE);
	    unlink(VI_GDB_FILE);
	}
    }
#endif

#ifdef SIGHASARG
    // try to find the name of this signal
    for (i = 0; signal_info[i].sig != -1; i++)
	if (sigarg == signal_info[i].sig)
	    break;
    deadly_signal = sigarg;
#endif

    full_screen = FALSE;	// don't write message to the GUI, it might be
				// part of the problem...
    /*
     * If something goes wrong after entering here, we may get here again.
     * When this happens, give a message and try to exit nicely (resetting the
     * terminal mode, etc.)
     * When this happens twice, just exit, don't even try to give a message,
     * stack may be corrupt or something weird.
     * When this still happens again (or memory was corrupted in such a way
     * that "entered" was clobbered) use _exit(), don't try freeing resources.
     */
    if (entered >= 3)
    {
	reset_signals();	// don't catch any signals anymore
	may_core_dump();
	if (entered >= 4)
	    _exit(8);
	exit(7);
    }
    if (entered == 2)
    {
	// No translation, it may call malloc().
	OUT_STR("Vim: Double signal, exiting\n");
	out_flush();
	getout(1);
    }

    // No translation, it may call malloc().
#ifdef SIGHASARG
    sprintf((char *)IObuff, "Vim: Caught deadly signal %s\r\n",
							 signal_info[i].name);
#else
    sprintf((char *)IObuff, "Vim: Caught deadly signal\r\n");
#endif

    // Preserve files and exit.  This sets the really_exiting flag to prevent
    // calling free().
    preserve_exit();

    // NOTREACHED

#ifdef NBDEBUG
    reset_signals();
    may_core_dump();
    abort();
#endif
}

/*
 * Invoked after receiving SIGCONT.  We don't know what happened while
 * sleeping, deal with part of that.
 */
    static void
after_sigcont(void)
{
    // Don't change "oldtitle" in a signal handler, set a flag to obtain it
    // again later.
    oldtitle_outdated = TRUE;

    settmode(TMODE_RAW);
    need_check_timestamps = TRUE;
    did_check_timestamps = FALSE;
}

#if defined(SIGCONT)
static void sigcont_handler SIGPROTOARG;

/*
 * With multi-threading, suspending might not work immediately.  Catch the
 * SIGCONT signal, which will be used as an indication whether the suspending
 * has been done or not.
 *
 * On Linux, signal is not always handled immediately either.
 * See https://bugs.launchpad.net/bugs/291373
 * Probably because the signal is handled in another thread.
 *
 * volatile because it is used in signal handler sigcont_handler().
 */
static volatile sig_atomic_t sigcont_received;
static void sigcont_handler SIGPROTOARG;

/*
 * signal handler for SIGCONT
 */
    static void
sigcont_handler SIGDEFARG(sigarg)
{
    if (in_mch_suspend)
    {
	sigcont_received = TRUE;
    }
    else
    {
	// We didn't suspend ourselves, assume we were stopped by a SIGSTOP
	// signal (which can't be intercepted) and get a SIGCONT.  Need to get
	// back to a sane mode. We should redraw, but we can't really do that
	// in a signal handler, do a redraw later.
	after_sigcont();
	redraw_later(UPD_CLEAR);
	cursor_on_force();
	out_flush();
    }
}
#endif

#if defined(FEAT_CLIPBOARD) && defined(FEAT_X11)
# ifdef USE_SYSTEM
static void *clip_star_save = NULL;
static void *clip_plus_save = NULL;
# endif

/*
 * Called when Vim is going to sleep or execute a shell command.
 * We can't respond to requests for the X selections.  Lose them, otherwise
 * other applications will hang.  But first copy the text to cut buffer 0.
 */
    static void
loose_clipboard(void)
{
    if (clip_star.owned || clip_plus.owned)
    {
	x11_export_final_selection();
	if (clip_star.owned)
	    clip_lose_selection(&clip_star);
	if (clip_plus.owned)
	    clip_lose_selection(&clip_plus);
	if (x11_display != NULL)
	    XFlush(x11_display);
    }
}

# ifdef USE_SYSTEM
/*
 * Save clipboard text to restore later.
 */
    static void
save_clipboard(void)
{
    if (clip_star.owned)
	clip_star_save = get_register('*', TRUE);
    if (clip_plus.owned)
	clip_plus_save = get_register('+', TRUE);
}

/*
 * Restore clipboard text if no one own the X selection.
 */
    static void
restore_clipboard(void)
{
    if (clip_star_save != NULL)
    {
	if (!clip_gen_owner_exists(&clip_star))
	    put_register('*', clip_star_save);
	else
	    free_register(clip_star_save);
	clip_star_save = NULL;
    }
    if (clip_plus_save != NULL)
    {
	if (!clip_gen_owner_exists(&clip_plus))
	    put_register('+', clip_plus_save);
	else
	    free_register(clip_plus_save);
	clip_plus_save = NULL;
    }
}
# endif
#endif

/*
 * If the machine has job control, use it to suspend the program,
 * otherwise fake it by starting a new shell.
 */
    void
mch_suspend(void)
{
    if (ignore_sigtstp)
	return;

#if defined(SIGTSTP)
    in_mch_suspend = TRUE;

    out_flush();	    // needed to make cursor visible on some systems
    settmode(TMODE_COOK);
    out_flush();	    // needed to disable mouse on some systems

# if defined(FEAT_CLIPBOARD) && defined(FEAT_X11)
    loose_clipboard();
# endif
# if defined(SIGCONT)
    sigcont_received = FALSE;
# endif

    kill(0, SIGTSTP);	    // send ourselves a STOP signal

# if defined(SIGCONT)
    /*
     * Wait for the SIGCONT signal to be handled. It generally happens
     * immediately, but somehow not all the time, probably because it's handled
     * in another thread. Do not call pause() because there would be race
     * condition which would hang Vim if signal happened in between the test of
     * sigcont_received and the call to pause(). If signal is not yet received,
     * sleep 0, 1, 2, 3 ms. Don't bother waiting further if signal is not
     * received after 1+2+3 ms (not expected to happen).
     */
    {
	long wait_time;

	for (wait_time = 0; !sigcont_received && wait_time <= 3L; wait_time++)
	    mch_delay(wait_time, 0);
    }
# endif
    in_mch_suspend = FALSE;

    after_sigcont();
#else
    suspend_shell();
#endif
}

    void
mch_init(void)
{
    Columns = 80;
    Rows = 24;

    out_flush();

#ifdef SIGTSTP
    // Check whether we were invoked with SIGTSTP set to be ignored. If it is
    // that indicates the shell (or program) that launched us does not support
    // tty job control and thus we should ignore that signal. If invoked as a
    // restricted editor (e.g., as "rvim") SIGTSTP is always ignored.
    ignore_sigtstp = restricted || SIG_IGN == mch_signal(SIGTSTP, SIG_ERR);
#endif
    set_signals();

#ifdef MACOS_CONVERT
    mac_conv_init();
#endif
#ifdef FEAT_CYGWIN_WIN32_CLIPBOARD
    win_clip_init();
#endif
}

    static void
set_signals(void)
{
#if defined(SIGWINCH)
    /*
     * WINDOW CHANGE signal is handled with sig_winch().
     */
    mch_signal(SIGWINCH, sig_winch);
#endif

#ifdef SIGTSTP
    // See mch_init() for the conditions under which we ignore SIGTSTP.
    // In the GUI default TSTP processing is OK.
    // Checking both gui.in_use and gui.starting because gui.in_use is not set
    // at this point (set after menus are displayed), but gui.starting is set.
    mch_signal(SIGTSTP, ignore_sigtstp ? SIG_IGN
# ifdef FEAT_GUI
				: gui.in_use || gui.starting ? SIG_DFL
# endif
				    : sig_tstp);
#endif
#if defined(SIGCONT)
    mch_signal(SIGCONT, sigcont_handler);
#endif
#ifdef SIGPIPE
    /*
     * We want to ignore breaking of PIPEs.
     */
    mch_signal(SIGPIPE, SIG_IGN);
#endif

#ifdef SIGINT
    catch_int_signal();
#endif

#ifdef SIGUSR1
    /*
     * Call user's handler on SIGUSR1
     */
    mch_signal(SIGUSR1, catch_sigusr1);
#endif

    /*
     * Ignore alarm signals (Perl's alarm() generates it).
     */
#ifdef SIGALRM
    mch_signal(SIGALRM, SIG_IGN);
#endif

#ifdef SIGPWR
    /*
     * Catch SIGPWR (power failure?) to preserve the swap files, so that no
     * work will be lost.
     */
    mch_signal(SIGPWR, catch_sigpwr);
#endif

    /*
     * Arrange for other signals to gracefully shutdown Vim.
     */
    catch_signals(deathtrap, SIG_ERR);

#if defined(FEAT_GUI) && defined(SIGHUP)
    /*
     * When the GUI is running, ignore the hangup signal.
     */
    if (gui.in_use)
	mch_signal(SIGHUP, SIG_IGN);
#endif
}

#if defined(SIGINT) || defined(PROTO)
/*
 * Catch CTRL-C (only works while in Cooked mode).
 */
    static void
catch_int_signal(void)
{
    mch_signal(SIGINT, catch_sigint);
}
#endif

    void
reset_signals(void)
{
    catch_signals(SIG_DFL, SIG_DFL);
#if defined(SIGCONT)
    // SIGCONT isn't in the list, because its default action is ignore
    mch_signal(SIGCONT, SIG_DFL);
#endif
}

    static void
catch_signals(
    void (*func_deadly)(int),
    void (*func_other)(int))
{
    int	    i;

    for (i = 0; signal_info[i].sig != -1; i++)
    {
	if (signal_info[i].deadly)
	{
#if defined(HAVE_SIGALTSTACK) && defined(HAVE_SIGACTION)
	    struct sigaction sa;

	    // Setup to use the alternate stack for the signal function.
	    sa.sa_handler = func_deadly;
	    sigemptyset(&sa.sa_mask);
# if defined(__linux__) && defined(_REENTRANT)
	    // On Linux, with glibc compiled for kernel 2.2, there is a bug in
	    // thread handling in combination with using the alternate stack:
	    // pthread library functions try to use the stack pointer to
	    // identify the current thread, causing a SEGV signal, which
	    // recursively calls deathtrap() and hangs.
	    sa.sa_flags = 0;
# else
	    sa.sa_flags = SA_ONSTACK;
# endif
	    sigaction(signal_info[i].sig, &sa, NULL);
#else
# if defined(HAVE_SIGALTSTACK) && defined(HAVE_SIGVEC)
	    struct sigvec sv;

	    // Setup to use the alternate stack for the signal function.
	    sv.sv_handler = func_deadly;
	    sv.sv_mask = 0;
	    sv.sv_flags = SV_ONSTACK;
	    sigvec(signal_info[i].sig, &sv, NULL);
# else
	    mch_signal(signal_info[i].sig, func_deadly);
# endif
#endif
	}
	else if (func_other != SIG_ERR)
	{
	    // Deal with non-deadly signals.
#ifdef SIGTSTP
	    mch_signal(signal_info[i].sig,
		    signal_info[i].sig == SIGTSTP && ignore_sigtstp
						       ? SIG_IGN : func_other);
#else
	    mch_signal(signal_info[i].sig, func_other);
#endif
	}
    }
}

#ifdef HAVE_SIGPROCMASK
    static void
block_signals(sigset_t *set)
{
    sigset_t	newset;
    int		i;

    sigemptyset(&newset);

    for (i = 0; signal_info[i].sig != -1; i++)
	sigaddset(&newset, signal_info[i].sig);

# if defined(SIGCONT)
    // SIGCONT isn't in the list, because its default action is ignore
    sigaddset(&newset, SIGCONT);
# endif

    sigprocmask(SIG_BLOCK, &newset, set);
}

    static void
unblock_signals(sigset_t *set)
{
    sigprocmask(SIG_SETMASK, set, NULL);
}
#endif

/*
 * Handling of SIGHUP, SIGQUIT and SIGTERM:
 * "when" == a signal:       when busy, postpone and return FALSE, otherwise
 *			     return TRUE
 * "when" == SIGNAL_BLOCK:   Going to be busy, block signals
 * "when" == SIGNAL_UNBLOCK: Going to wait, unblock signals, use postponed
 *			     signal
 * Returns TRUE when Vim should exit.
 */
    int
vim_handle_signal(int sig)
{
    static int got_signal = 0;
    static int blocked = TRUE;

    switch (sig)
    {
	case SIGNAL_BLOCK:   blocked = TRUE;
			     break;

	case SIGNAL_UNBLOCK: blocked = FALSE;
			     if (got_signal != 0)
			     {
				 kill(getpid(), got_signal);
				 got_signal = 0;
			     }
			     break;

	default:	     if (!blocked)
				 return TRUE;	// exit!
			     got_signal = sig;
#ifdef SIGPWR
			     if (sig != SIGPWR)
#endif
				 got_int = TRUE;    // break any loops
			     break;
    }
    return FALSE;
}

/*
 * Check_win checks whether we have an interactive stdout.
 */
    int
mch_check_win(int argc UNUSED, char **argv UNUSED)
{
    if (isatty(1))
	return OK;
    return FAIL;
}

/*
 * Return TRUE if the input comes from a terminal, FALSE otherwise.
 */
    int
mch_input_isatty(void)
{
    if (isatty(read_cmd_fd))
	return TRUE;
    return FALSE;
}

#ifdef FEAT_X11

# if defined(ELAPSED_TIMEVAL)

/*
 * Give a message about the elapsed time for opening the X window.
 */
    static void
xopen_message(long elapsed_msec)
{
    smsg(_("Opening the X display took %ld msec"), elapsed_msec);
}
# endif
#endif

#if defined(FEAT_X11)
/*
 * A few functions shared by X11 title and clipboard code.
 */

static int	got_x_error = FALSE;

/*
 * X Error handler, otherwise X just exits!  (very rude) -- webb
 */
    static int
x_error_handler(Display *dpy, XErrorEvent *error_event)
{
    XGetErrorText(dpy, error_event->error_code, (char *)IObuff, IOSIZE);
    STRCAT(IObuff, _("\nVim: Got X error\n"));

    // In the GUI we cannot print a message and continue, because no X calls
    // are allowed here (causes my system to hang).  Silently continuing seems
    // like the best alternative.  Do preserve files, in case we crash.
    ml_sync_all(FALSE, FALSE);

#ifdef FEAT_GUI
    if (!gui.in_use)
#endif
	msg((char *)IObuff);

    return 0;		// NOTREACHED
}

/*
 * Another X Error handler, just used to check for errors.
 */
    static int
x_error_check(Display *dpy UNUSED, XErrorEvent *error_event UNUSED)
{
    got_x_error = TRUE;
    return 0;
}

/*
 * Return TRUE when connection to the X server is desired.
 */
    static int
x_connect_to_server(void)
{
    // No point in connecting if we are exiting or dying.
    if (exiting || v_dying)
	return FALSE;

#if defined(FEAT_CLIENTSERVER)
    if (x_force_connect)
	return TRUE;
#endif
    if (x_no_connect)
	return FALSE;

    // Check for a match with "exclude:" from 'clipboard'.
    if (clip_exclude_prog != NULL)
    {
	// Just in case we get called recursively, return FALSE.  This could
	// happen if vpeekc() is used while executing the prog and it causes a
	// related callback to be invoked.
	if (regprog_in_use(clip_exclude_prog))
	    return FALSE;

	if (vim_regexec_prog(&clip_exclude_prog, FALSE, T_NAME, (colnr_T)0))
	    return FALSE;
    }
    return TRUE;
}

#if defined(FEAT_X11) && defined(FEAT_XCLIPBOARD)
# if defined(USING_SETJMP)
/*
 * An X IO Error handler, used to catch error while opening the display.
 */
    static int
x_IOerror_check(Display *dpy UNUSED)
{
    // This function should not return, it causes exit().  Longjump instead.
    LONGJMP(lc_jump_env, 1);
#  if defined(VMS) || defined(__CYGWIN__)
    return 0;  // avoid the compiler complains about missing return value
#  endif
}
# endif

/*
 * An X IO Error handler, used to catch terminal errors.
 */
static int xterm_dpy_retry_count = 0;

    static int
x_IOerror_handler(Display *dpy UNUSED)
{
    xterm_dpy = NULL;
    xterm_dpy_retry_count = 5;  // Try reconnecting five times
    x11_window = 0;
    x11_display = NULL;
    xterm_Shell = (Widget)0;

    // This function should not return, it causes exit().  Longjump instead.
    LONGJMP(x_jump_env, 1);
# if defined(VMS) || defined(__CYGWIN__)
    return 0;  // avoid the compiler complains about missing return value
# endif
}

/*
 * If the X11 connection was lost try to restore it.
 * Helps when the X11 server was stopped and restarted while Vim was inactive
 * (e.g. through tmux).
 */
    static void
may_restore_clipboard(void)
{
    // No point in restoring the connecting if we are exiting or dying.
    if (!exiting && !v_dying && xterm_dpy_retry_count > 0)
    {
	--xterm_dpy_retry_count;

# ifndef LESSTIF_VERSION
	// This has been reported to avoid Vim getting stuck.
	if (app_context != (XtAppContext)NULL)
	{
	    XtDestroyApplicationContext(app_context);
	    app_context = (XtAppContext)NULL;
	    x11_display = NULL; // freed by XtDestroyApplicationContext()
	}
# endif

	setup_term_clip();
	get_x11_title(FALSE);
    }
}

    void
ex_xrestore(exarg_T *eap)
{
    if (eap->arg != NULL && STRLEN(eap->arg) > 0)
    {
	if (xterm_display_allocated)
	    vim_free(xterm_display);
	xterm_display = (char *)vim_strsave(eap->arg);
	xterm_display_allocated = TRUE;
    }
    smsg(_("restoring display %s"), xterm_display == NULL
		    ? (char *)mch_getenv((char_u *)"DISPLAY") : xterm_display);

    clear_xterm_clip();
    x11_window = 0;
    xterm_dpy_retry_count = 5;  // Try reconnecting five times
    may_restore_clipboard();
}
#endif

/*
 * Test if "dpy" and x11_window are valid by getting the window title.
 * I don't actually want it yet, so there may be a simpler call to use, but
 * this will cause the error handler x_error_check() to be called if anything
 * is wrong, such as the window pointer being invalid (as can happen when the
 * user changes his DISPLAY, but not his WINDOWID) -- webb
 */
    static int
test_x11_window(Display *dpy)
{
    int			(*old_handler)(Display*, XErrorEvent*);
    XTextProperty	text_prop;

    old_handler = XSetErrorHandler(x_error_check);
    got_x_error = FALSE;
    if (XGetWMName(dpy, x11_window, &text_prop))
	XFree((void *)text_prop.value);
    XSync(dpy, False);
    (void)XSetErrorHandler(old_handler);

    if (p_verbose > 0 && got_x_error)
	verb_msg(_("Testing the X display failed"));

    return (got_x_error ? FAIL : OK);
}
#endif


#ifdef FEAT_X11

static int get_x11_thing(int get_title, int test_only);

/*
 * try to get x11 window and display
 *
 * return FAIL for failure, OK otherwise
 */
    static int
get_x11_windis(void)
{
    char	    *winid;
    static int	    result = -1;
#define XD_NONE	 0	// x11_display not set here
#define XD_HERE	 1	// x11_display opened here
#define XD_GUI	 2	// x11_display used from gui.dpy
#define XD_XTERM 3	// x11_display used from xterm_dpy
    static int	    x11_display_from = XD_NONE;
    static int	    did_set_error_handler = FALSE;

    if (!did_set_error_handler)
    {
	// X just exits if it finds an error otherwise!
	(void)XSetErrorHandler(x_error_handler);
	did_set_error_handler = TRUE;
    }

#if defined(FEAT_GUI_X11) || defined(FEAT_GUI_GTK)
    if (gui.in_use)
    {
	/*
	 * If the X11 display was opened here before, for the window where Vim
	 * was started, close that one now to avoid a memory leak.
	 */
	if (x11_display_from == XD_HERE && x11_display != NULL)
	{
	    XCloseDisplay(x11_display);
	    x11_display_from = XD_NONE;
	}
	if (gui_get_x11_windis(&x11_window, &x11_display) == OK)
	{
	    x11_display_from = XD_GUI;
	    return OK;
	}
	x11_display = NULL;
	return FAIL;
    }
    else if (x11_display_from == XD_GUI)
    {
	// GUI must have stopped somehow, clear x11_display
	x11_window = 0;
	x11_display = NULL;
	x11_display_from = XD_NONE;
    }
#endif

    // When started with the "-X" argument, don't try connecting.
    if (!x_connect_to_server())
	return FAIL;

    /*
     * If WINDOWID not set, should try another method to find out
     * what the current window number is. The only code I know for
     * this is very complicated.
     * We assume that zero is invalid for WINDOWID.
     */
    if (x11_window == 0 && (winid = getenv("WINDOWID")) != NULL)
	x11_window = (Window)atol(winid);

#ifdef FEAT_XCLIPBOARD
    if (xterm_dpy == x11_display)
	// x11_display may have been set to xterm_dpy elsewhere
	x11_display_from = XD_XTERM;

    if (xterm_dpy != NULL && x11_window != 0)
    {
	// We may have checked it already, but Gnome terminal can move us to
	// another window, so we need to check every time.
	if (x11_display_from != XD_XTERM)
	{
	    /*
	     * If the X11 display was opened here before, for the window where
	     * Vim was started, close that one now to avoid a memory leak.
	     */
	    if (x11_display_from == XD_HERE && x11_display != NULL)
		XCloseDisplay(x11_display);
	    x11_display = xterm_dpy;
	    x11_display_from = XD_XTERM;
	}
	if (test_x11_window(x11_display) == FAIL)
	{
	    // probably bad $WINDOWID
	    x11_window = 0;
	    x11_display = NULL;
	    x11_display_from = XD_NONE;
	    return FAIL;
	}
	return OK;
    }
#endif

    if (x11_window == 0 || x11_display == NULL)
	result = -1;

    if (result != -1)	    // Have already been here and set this
	return result;	    // Don't do all these X calls again

    if (x11_window != 0 && x11_display == NULL)
    {
#ifdef SET_SIG_ALARM
	sighandler_T sig_save;
#endif
#ifdef ELAPSED_FUNC
	elapsed_T start_tv;

	if (p_verbose > 0)
	    ELAPSED_INIT(start_tv);
#endif

#ifdef SET_SIG_ALARM
	/*
	 * Opening the Display may hang if the DISPLAY setting is wrong, or
	 * the network connection is bad.  Set an alarm timer to get out.
	 */
	sig_alarm_called = FALSE;
	sig_save = mch_signal(SIGALRM, sig_alarm);
	alarm(2);
#endif
	x11_display = XOpenDisplay(NULL);

#ifdef SET_SIG_ALARM
	alarm(0);
	mch_signal(SIGALRM, sig_save);
	if (p_verbose > 0 && sig_alarm_called)
	    verb_msg(_("Opening the X display timed out"));
#endif
	if (x11_display != NULL)
	{
# ifdef ELAPSED_FUNC
	    if (p_verbose > 0)
	    {
		verbose_enter();
		xopen_message(ELAPSED_FUNC(start_tv));
		verbose_leave();
	    }
# endif
	    if (test_x11_window(x11_display) == FAIL)
	    {
		// Maybe window id is bad
		x11_window = 0;
		XCloseDisplay(x11_display);
		x11_display = NULL;
	    }
	    else
		x11_display_from = XD_HERE;
	}
    }
    if (x11_window == 0 || x11_display == NULL)
	return (result = FAIL);

# ifdef FEAT_EVAL
    set_vim_var_nr(VV_WINDOWID, (long)x11_window);
# endif

    return (result = OK);
}

/*
 * Determine original x11 Window Title
 */
    static int
get_x11_title(int test_only)
{
    return get_x11_thing(TRUE, test_only);
}

/*
 * Determine original x11 Window icon
 */
    static int
get_x11_icon(int test_only)
{
    int		retval = FALSE;

    retval = get_x11_thing(FALSE, test_only);

    // could not get old icon, use terminal name
    if (oldicon == NULL && !test_only)
    {
	if (STRNCMP(T_NAME, "builtin_", 8) == 0)
	    oldicon = vim_strsave(T_NAME + 8);
	else
	    oldicon = vim_strsave(T_NAME);
    }

    return retval;
}

    static int
get_x11_thing(
    int		get_title,	// get title string
    int		test_only)
{
    XTextProperty	text_prop;
    int			retval = FALSE;
    Status		status;

    if (get_x11_windis() != OK)
	return FALSE;

    // Get window/icon name if any
    if (get_title)
	status = XGetWMName(x11_display, x11_window, &text_prop);
    else
	status = XGetWMIconName(x11_display, x11_window, &text_prop);

    /*
     * If terminal is xterm, then x11_window may be a child window of the
     * outer xterm window that actually contains the window/icon name, so
     * keep traversing up the tree until a window with a title/icon is
     * found.
     */
    // Previously this was only done for xterm and alike.  I don't see a
    // reason why it would fail for other terminal emulators.
    // if (term_is_xterm)
    Window	    root;
    Window	    parent;
    Window	    win = x11_window;
    Window	   *children;
    unsigned int    num_children;

    while (!status || text_prop.value == NULL)
    {
	if (!XQueryTree(x11_display, win, &root, &parent, &children,
		    &num_children))
	    break;
	if (children)
	    XFree((void *)children);
	if (parent == root || parent == 0)
	    break;

	win = parent;
	if (get_title)
	    status = XGetWMName(x11_display, win, &text_prop);
	else
	    status = XGetWMIconName(x11_display, win, &text_prop);
    }

    if (status && text_prop.value != NULL)
    {
	retval = TRUE;
	if (!test_only)
	{
	    if (get_title)
		vim_free(oldtitle);
	    else
		vim_free(oldicon);
	    if (text_prop.encoding == XA_STRING && !has_mbyte)
	    {
		if (get_title)
		    oldtitle = vim_strsave((char_u *)text_prop.value);
		else
		    oldicon = vim_strsave((char_u *)text_prop.value);
	    }
	    else
	    {
		char    **cl;
		Status  transform_status;
		int	    n = 0;

		transform_status = XmbTextPropertyToTextList(x11_display,
			&text_prop,
			&cl, &n);
		if (transform_status >= Success && n > 0 && cl[0])
		{
		    if (get_title)
			oldtitle = vim_strsave((char_u *) cl[0]);
		    else
			oldicon = vim_strsave((char_u *) cl[0]);
		    XFreeStringList(cl);
		}
		else
		{
		    if (get_title)
			oldtitle = vim_strsave((char_u *)text_prop.value);
		    else
			oldicon = vim_strsave((char_u *)text_prop.value);
		}
	    }
	}
	XFree((void *)text_prop.value);
    }
    return retval;
}

// Xutf8 functions are not available on older systems. Note that on some
// systems X_HAVE_UTF8_STRING may be defined in a header file but
// Xutf8SetWMProperties() is not in the X11 library.  Configure checks for
// that and defines HAVE_XUTF8SETWMPROPERTIES.
#if defined(X_HAVE_UTF8_STRING)
# if X_HAVE_UTF8_STRING && HAVE_XUTF8SETWMPROPERTIES
#  define USE_UTF8_STRING
# endif
#endif

/*
 * Set x11 Window Title
 *
 * get_x11_windis() must be called before this and have returned OK
 */
    static void
set_x11_title(char_u *title)
{
	// XmbSetWMProperties() and Xutf8SetWMProperties() should use a STRING
	// when possible, COMPOUND_TEXT otherwise.  COMPOUND_TEXT isn't
	// supported everywhere and STRING doesn't work for multi-byte titles.
#ifdef USE_UTF8_STRING
    if (enc_utf8)
	Xutf8SetWMProperties(x11_display, x11_window, (const char *)title,
					     NULL, NULL, 0, NULL, NULL, NULL);
    else
#endif
    {
#if XtSpecificationRelease >= 4
# ifdef FEAT_XFONTSET
	XmbSetWMProperties(x11_display, x11_window, (const char *)title,
					     NULL, NULL, 0, NULL, NULL, NULL);
# else
	XTextProperty	text_prop;
	char		*c_title = (char *)title;

	// directly from example 3-18 "basicwin" of Xlib Programming Manual
	(void)XStringListToTextProperty(&c_title, 1, &text_prop);
	XSetWMProperties(x11_display, x11_window, &text_prop,
					     NULL, NULL, 0, NULL, NULL, NULL);
# endif
#else
	XStoreName(x11_display, x11_window, (char *)title);
#endif
    }
    XFlush(x11_display);
}

/*
 * Set x11 Window icon
 *
 * get_x11_windis() must be called before this and have returned OK
 */
    static void
set_x11_icon(char_u *icon)
{
    // See above for comments about using X*SetWMProperties().
#ifdef USE_UTF8_STRING
    if (enc_utf8)
	Xutf8SetWMProperties(x11_display, x11_window, NULL, (const char *)icon,
						   NULL, 0, NULL, NULL, NULL);
    else
#endif
    {
#if XtSpecificationRelease >= 4
# ifdef FEAT_XFONTSET
	XmbSetWMProperties(x11_display, x11_window, NULL, (const char *)icon,
						   NULL, 0, NULL, NULL, NULL);
# else
	XTextProperty	text_prop;
	char		*c_icon = (char *)icon;

	(void)XStringListToTextProperty(&c_icon, 1, &text_prop);
	XSetWMProperties(x11_display, x11_window, NULL, &text_prop,
						   NULL, 0, NULL, NULL, NULL);
# endif
#else
	XSetIconName(x11_display, x11_window, (char *)icon);
#endif
    }
    XFlush(x11_display);
}

#else  // FEAT_X11

    static int
get_x11_title(int test_only UNUSED)
{
    return FALSE;
}

    static int
get_x11_icon(int test_only)
{
    if (!test_only)
    {
	if (STRNCMP(T_NAME, "builtin_", 8) == 0)
	    oldicon = vim_strsave(T_NAME + 8);
	else
	    oldicon = vim_strsave(T_NAME);
    }
    return FALSE;
}

#endif // FEAT_X11

    int
mch_can_restore_title(void)
{
    return get_x11_title(TRUE);
}

    int
mch_can_restore_icon(void)
{
    return get_x11_icon(TRUE);
}

/*
 * Set the window title and icon.
 */
    void
mch_settitle(char_u *title, char_u *icon)
{
    int		type = 0;
    static int	recursive = 0;

    if (T_NAME == NULL)	    // no terminal name (yet)
	return;
    if (title == NULL && icon == NULL)	    // nothing to do
	return;

    // When one of the X11 functions causes a deadly signal, we get here again
    // recursively.  Avoid hanging then (something is probably locked).
    if (recursive)
	return;
    ++recursive;

    /*
     * if the window ID and the display is known, we may use X11 calls
     */
#ifdef FEAT_X11
    if (get_x11_windis() == OK)
	type = 1;
#endif
#if defined(FEAT_GUI_PHOTON) \
    || defined(FEAT_GUI_GTK) || defined(FEAT_GUI_HAIKU)
    if (gui.in_use)
	type = 1;
#endif

    /*
     * Note: if "t_ts" is set, title is set with escape sequence rather
     *	     than x11 calls, because the x11 calls don't always work
     */
    if ((type || *T_TS != NUL) && title != NULL)
    {
	if (oldtitle_outdated)
	{
	    oldtitle_outdated = FALSE;
	    VIM_CLEAR(oldtitle);
	}
	if (oldtitle == NULL
#ifdef FEAT_GUI
		&& !gui.in_use
#endif
		)		// first call but not in GUI, save title
	    (void)get_x11_title(FALSE);

	if (*T_TS != NUL)		// it's OK if t_fs is empty
	    term_settitle(title);
#ifdef FEAT_X11
	else
# ifdef FEAT_GUI_GTK
	if (!gui.in_use)		// don't do this if GTK+ is running
# endif
	    set_x11_title(title);		// x11
#endif
#if defined(FEAT_GUI_GTK) || defined(FEAT_GUI_HAIKU) \
	|| defined(FEAT_GUI_PHOTON)
	else
	    gui_mch_settitle(title, icon);
#endif
	unix_did_set_title = TRUE;
    }

    if ((type || *T_CIS != NUL) && icon != NULL)
    {
	if (oldicon == NULL
#ifdef FEAT_GUI
		&& !gui.in_use
#endif
		)		// first call, save icon
	    get_x11_icon(FALSE);

	if (*T_CIS != NUL)
	{
	    out_str(T_CIS);			// set icon start
	    out_str_nf(icon);
	    out_str(T_CIE);			// set icon end
	    out_flush();
	}
#ifdef FEAT_X11
	else
# ifdef FEAT_GUI_GTK
	if (!gui.in_use)		// don't do this if GTK+ is running
# endif
	    set_x11_icon(icon);			// x11
#endif
	did_set_icon = TRUE;
    }
    --recursive;
}

/*
 * Restore the window/icon title.
 * "which" is one of:
 *  SAVE_RESTORE_TITLE only restore title
 *  SAVE_RESTORE_ICON  only restore icon
 *  SAVE_RESTORE_BOTH  restore title and icon
 */
    void
mch_restore_title(int which)
{
    int	do_push_pop = unix_did_set_title || did_set_icon;

    // Only restore the title or icon when it has been set.
    // When using "oldtitle" make a copy, it might be freed halfway.
    char_u *title = ((which & SAVE_RESTORE_TITLE) && unix_did_set_title)
			? (oldtitle ? oldtitle : p_titleold) : NULL;
    char_u *tofree = NULL;
    if (title == oldtitle && oldtitle != NULL)
    {
	tofree = vim_strsave(title);
	if (tofree != NULL)
	    title = tofree;
    }
    mch_settitle(title,
	       ((which & SAVE_RESTORE_ICON) && did_set_icon) ? oldicon : NULL);
    vim_free(tofree);

    if (do_push_pop)
    {
	// pop and push from/to the stack
	term_pop_title(which);
	term_push_title(which);
    }
}


/*
 * Return TRUE if "name" looks like some xterm name.
 * This matches "xterm.*", thus "xterm-256color", "xterm-kitty", etc.
 * Do not consider "xterm-kitty" an xterm, it is not fully xterm compatible,
 * using the "xterm-kitty" terminfo entry should work better.
 * Seiichi Sato mentioned that "mlterm" works like xterm.
 */
    int
vim_is_xterm(char_u *name)
{
    if (name == NULL)
	return FALSE;
    return ((STRNICMP(name, "xterm", 5) == 0
				     && STRNICMP(name, "xterm-kitty", 11) != 0)
		|| STRNICMP(name, "nxterm", 6) == 0
		|| STRNICMP(name, "kterm", 5) == 0
		|| STRNICMP(name, "mlterm", 6) == 0
		|| STRNICMP(name, "rxvt", 4) == 0
		|| STRNICMP(name, "screen.xterm", 12) == 0
		|| STRCMP(name, "builtin_xterm") == 0);
}

#if defined(FEAT_MOUSE_XTERM) || defined(PROTO)
/*
 * Return TRUE if "name" appears to be that of a terminal
 * known to support the xterm-style mouse protocol.
 * Relies on term_is_xterm having been set to its correct value.
 */
    int
use_xterm_like_mouse(char_u *name)
{
    return (name != NULL
	    && (term_is_xterm
		|| STRNICMP(name, "screen", 6) == 0
		|| STRNICMP(name, "tmux", 4) == 0
		|| STRNICMP(name, "gnome", 5) == 0
		|| STRICMP(name, "st") == 0
		|| STRNICMP(name, "st-", 3) == 0
		|| STRNICMP(name, "stterm", 6) == 0));
}
#endif

/*
 * Return non-zero when using an xterm mouse, according to 'ttymouse'.
 * Return 1 for "xterm".
 * Return 2 for "xterm2".
 * Return 3 for "urxvt".
 * Return 4 for "sgr".
 */
    int
use_xterm_mouse(void)
{
    if (ttym_flags == TTYM_SGR)
	return 4;
    if (ttym_flags == TTYM_URXVT)
	return 3;
    if (ttym_flags == TTYM_XTERM2)
	return 2;
    if (ttym_flags == TTYM_XTERM)
	return 1;
    return 0;
}

/*
 * Return TRUE if "name" is an iris-ansi terminal name.
 */
    int
vim_is_iris(char_u *name)
{
    if (name == NULL)
	return FALSE;
    return (STRNICMP(name, "iris-ansi", 9) == 0
	    || STRCMP(name, "builtin_iris-ansi") == 0);
}

#if defined(VMS) || defined(PROTO)
/*
 * Return TRUE if "name" is a vt300-like terminal name.
 */
    int
vim_is_vt300(char_u *name)
{
    if (name == NULL)
	return FALSE;
    // Actually all ANSI compatible terminals should be here.
    // Catch at least VT1xx - VT5xx
    return ((STRNICMP(name, "vt", 2) == 0
			     && vim_strchr((char_u *)"12345", name[2]) != NULL)
	    || STRCMP(name, "builtin_vt320") == 0);
}
#endif

/*
 * Insert user name in s[len].
 * Return OK if a name found.
 */
    int
mch_get_user_name(char_u *s, int len)
{
#ifdef VMS
    vim_strncpy(s, (char_u *)cuserid(NULL), len - 1);
    return OK;
#else
    return mch_get_uname(getuid(), s, len);
#endif
}

/*
 * Insert user name for "uid" in s[len].
 * Return OK if a name found.
 */
    int
mch_get_uname(uid_t uid, char_u *s, int len)
{
#if defined(HAVE_PWD_H) && defined(HAVE_GETPWUID)
    struct passwd   *pw;

    if ((pw = getpwuid(uid)) != NULL
	    && pw->pw_name != NULL && *(pw->pw_name) != NUL)
    {
	vim_strncpy(s, (char_u *)pw->pw_name, len - 1);
	return OK;
    }
#endif
    sprintf((char *)s, "%d", (int)uid);	    // assumes s is long enough
    return FAIL;			    // a number is not a name
}

/*
 * Insert host name is s[len].
 */

#ifdef HAVE_SYS_UTSNAME_H
    void
mch_get_host_name(char_u *s, int len)
{
    struct utsname vutsname;

    if (uname(&vutsname) < 0)
	*s = NUL;
    else
	vim_strncpy(s, (char_u *)vutsname.nodename, len - 1);
}
#else // HAVE_SYS_UTSNAME_H

# ifdef HAVE_SYS_SYSTEMINFO_H
#  define gethostname(nam, len) sysinfo(SI_HOSTNAME, nam, len)
# endif

    void
mch_get_host_name(char_u *s, int len)
{
# ifdef VAXC
    vaxc$gethostname((char *)s, len);
# else
    gethostname((char *)s, len);
# endif
    s[len - 1] = NUL;	// make sure it's terminated
}
#endif // HAVE_SYS_UTSNAME_H

/*
 * return process ID
 */
    long
mch_get_pid(void)
{
    return (long)getpid();
}

/*
 * return TRUE if process "pid" is still running
 */
    int
mch_process_running(long pid)
{
    // If there is no error the process must be running.
    if (kill(pid, 0) == 0)
	return TRUE;
#ifdef ESRCH
    // If the error is ESRCH then the process is not running.
    if (errno == ESRCH)
	return FALSE;
#endif
    // If the process is running and owned by another user we get EPERM.  With
    // other errors the process might be running, assuming it is then.
    return TRUE;
}

#if !defined(HAVE_STRERROR) && defined(USE_GETCWD)
    static char *
strerror(int err)
{
    extern int	    sys_nerr;
    extern char	    *sys_errlist[];
    static char	    er[20];

    if (err > 0 && err < sys_nerr)
	return (sys_errlist[err]);
    sprintf(er, "Error %d", err);
    return er;
}
#endif

/*
 * Get name of current directory into buffer "buf" of length "len" bytes.
 * "len" must be at least PATH_MAX.
 * Return OK for success, FAIL for failure.
 */
    int
mch_dirname(char_u *buf, int len)
{
#if defined(USE_GETCWD)
    if (getcwd((char *)buf, len) == NULL)
    {
	STRCPY(buf, strerror(errno));
	return FAIL;
    }
    return OK;
#else
    return (getwd((char *)buf) != NULL ? OK : FAIL);
#endif
}

/*
 * Get absolute file name into "buf[len]".
 *
 * return FAIL for failure, OK for success
 */
    int
mch_FullName(
    char_u	*fname,
    char_u	*buf,
    int		len,
    int		force)		// also expand when already absolute path
{
    int		l;
#ifdef HAVE_FCHDIR
    int		fd = -1;
    static int	dont_fchdir = FALSE;	// TRUE when fchdir() doesn't work
#endif
    char_u	olddir[MAXPATHL];
    char_u	*p;
    int		retval = OK;
#ifdef __CYGWIN__
    char_u	posix_fname[MAXPATHL];	// Cygwin docs mention MAX_PATH, but
					// it's not always defined
#endif

#ifdef VMS
    fname = vms_fixfilename(fname);
#endif

#ifdef __CYGWIN__
    /*
     * This helps for when "/etc/hosts" is a symlink to "c:/something/hosts".
     */
# if CYGWIN_VERSION_DLL_MAJOR >= 1007
    // Use CCP_RELATIVE to avoid that it sometimes returns a path that ends in
    // a forward slash.
    cygwin_conv_path(CCP_WIN_A_TO_POSIX | CCP_RELATIVE,
		     fname, posix_fname, MAXPATHL);
# else
    cygwin_conv_to_posix_path(fname, posix_fname);
# endif
    fname = posix_fname;
#endif

    // Expand it if forced or not an absolute path.
    // Do not do it for "/file", the result is always "/".
    if ((force || !mch_isFullName(fname))
	    && ((p = vim_strrchr(fname, '/')) == NULL || p != fname))
    {
	/*
	 * If the file name has a path, change to that directory for a moment,
	 * and then get the directory (and get back to where we were).
	 * This will get the correct path name with "../" things.
	 */
	if (p != NULL)
	{
	    if (STRCMP(p, "/..") == 0)
		// for "/path/dir/.." include the "/.."
		p += 3;

#ifdef HAVE_FCHDIR
	    /*
	     * Use fchdir() if possible, it's said to be faster and more
	     * reliable.  But on SunOS 4 it might not work.  Check this by
	     * doing a fchdir() right now.
	     */
	    if (!dont_fchdir)
	    {
		fd = open(".", O_RDONLY | O_EXTRA, 0);
		if (fd >= 0 && fchdir(fd) < 0)
		{
		    close(fd);
		    fd = -1;
		    dont_fchdir = TRUE;	    // don't try again
		}
	    }
#endif

	    // Only change directory when we are sure we can return to where
	    // we are now.  After doing "su" chdir(".") might not work.
	    if (
#ifdef HAVE_FCHDIR
		fd < 0 &&
#endif
			(mch_dirname(olddir, MAXPATHL) == FAIL
					   || mch_chdir((char *)olddir) != 0))
	    {
		p = NULL;	// can't get current dir: don't chdir
		retval = FAIL;
	    }
	    else
	    {
		// The directory is copied into buf[], to be able to remove
		// the file name without changing it (could be a string in
		// read-only memory)
		if (p - fname >= len)
		    retval = FAIL;
		else
		{
		    vim_strncpy(buf, fname, p - fname);
		    if (mch_chdir((char *)buf))
		    {
			// Path does not exist (yet).  For a full path fail,
			// will use the path as-is.  For a relative path use
			// the current directory and append the file name.
			if (mch_isFullName(fname))
			    retval = FAIL;
			else
			    p = NULL;
		    }
		    else if (*p == '/')
			fname = p + 1;
		    else
			fname = p;
		    *buf = NUL;
		}
	    }
	}
	if (mch_dirname(buf, len) == FAIL)
	{
	    retval = FAIL;
	    *buf = NUL;
	}
	if (p != NULL)
	{
#ifdef HAVE_FCHDIR
	    if (fd >= 0)
	    {
		if (p_verbose >= 5)
		{
		    verbose_enter();
		    msg("fchdir() to previous dir");
		    verbose_leave();
		}
		l = fchdir(fd);
	    }
	    else
#endif
		l = mch_chdir((char *)olddir);
	    if (l != 0)
		emsg(_(e_cannot_go_back_to_previous_directory));
	}
#ifdef HAVE_FCHDIR
	if (fd >= 0)
	    close(fd);
#endif

	l = STRLEN(buf);
	if (l >= len - 1)
	    retval = FAIL; // no space for trailing "/"
#ifndef VMS
	else if (l > 0 && buf[l - 1] != '/' && *fname != NUL
						   && STRCMP(fname, ".") != 0)
	    STRCAT(buf, "/");
#endif
    }

    // Catch file names which are too long.
    if (retval == FAIL || (int)(STRLEN(buf) + STRLEN(fname)) >= len)
	return FAIL;

    // Do not append ".", "/dir/." is equal to "/dir".
    if (STRCMP(fname, ".") != 0)
	STRCAT(buf, fname);

    return OK;
}

/*
 * Return TRUE if "fname" does not depend on the current directory.
 */
    int
mch_isFullName(char_u *fname)
{
#ifdef VMS
    return ( fname[0] == '/'	       || fname[0] == '.'	    ||
	     strchr((char *)fname,':') || strchr((char *)fname,'"') ||
	    (strchr((char *)fname,'[') && strchr((char *)fname,']'))||
	    (strchr((char *)fname,'<') && strchr((char *)fname,'>'))   );
#else
    return (*fname == '/' || *fname == '~');
#endif
}

#if defined(USE_FNAME_CASE) || defined(PROTO)
/*
 * Set the case of the file name, if it already exists.  This will cause the
 * file name to remain exactly the same.
 * Only required for file systems where case is ignored and preserved.
 */
    void
fname_case(
    char_u	*name,
    int		len UNUSED)  // buffer size, only used when name gets longer
{
    struct stat st;
    char_u	*slash, *tail;
    DIR		*dirp;
    struct dirent *dp;

    if (mch_lstat((char *)name, &st) < 0)
	return;

    // Open the directory where the file is located.
    slash = vim_strrchr(name, '/');
    if (slash == NULL)
    {
	dirp = opendir(".");
	tail = name;
    }
    else
    {
	*slash = NUL;
	dirp = opendir((char *)name);
	*slash = '/';
	tail = slash + 1;
    }

    if (dirp == NULL)
	return;

    while ((dp = readdir(dirp)) != NULL)
    {
	// Only accept names that differ in case and are the same byte
	// length. TODO: accept different length name.
	if (STRICMP(tail, dp->d_name) == 0
		&& STRLEN(tail) == STRLEN(dp->d_name))
	{
	    char_u	newname[MAXPATHL + 1];
	    struct stat st2;

	    // Verify the inode is equal.
	    vim_strncpy(newname, name, MAXPATHL);
	    vim_strncpy(newname + (tail - name), (char_u *)dp->d_name,
		    MAXPATHL - (tail - name));
	    if (mch_lstat((char *)newname, &st2) >= 0
		    && st.st_ino == st2.st_ino
		    && st.st_dev == st2.st_dev)
	    {
		STRCPY(tail, dp->d_name);
		break;
	    }
	}
    }

    closedir(dirp);
}
#endif

/*
 * Get file permissions for 'name'.
 * Returns -1 when it doesn't exist.
 */
    long
mch_getperm(char_u *name)
{
    struct stat statb;

    // Keep the #ifdef outside of stat(), it may be a macro.
#ifdef VMS
    if (stat((char *)vms_fixfilename(name), &statb))
#else
    if (stat((char *)name, &statb))
#endif
	return -1;
#ifdef __INTERIX
    // The top bit makes the value negative, which means the file doesn't
    // exist.  Remove the bit, we don't use it.
    return statb.st_mode & ~S_ADDACE;
#else
    return statb.st_mode;
#endif
}

/*
 * Set file permission for "name" to "perm".
 * Return FAIL for failure, OK otherwise.
 */
    int
mch_setperm(char_u *name, long perm)
{
    return (chmod((char *)
#ifdef VMS
		    vms_fixfilename(name),
#else
		    name,
#endif
		    (mode_t)perm) == 0 ? OK : FAIL);
}

#if defined(HAVE_FCHMOD) || defined(PROTO)
/*
 * Set file permission for open file "fd" to "perm".
 * Return FAIL for failure, OK otherwise.
 */
    int
mch_fsetperm(int fd, long perm)
{
    return (fchmod(fd, (mode_t)perm) == 0 ? OK : FAIL);
}
#endif

#if defined(HAVE_ACL) || defined(PROTO)
# ifdef HAVE_SYS_ACL_H
#  include <sys/acl.h>
# endif
# ifdef HAVE_SYS_ACCESS_H
#  include <sys/access.h>
# endif

# ifdef HAVE_SOLARIS_ACL
typedef struct vim_acl_solaris_T {
    int acl_cnt;
    aclent_t *acl_entry;
} vim_acl_solaris_T;
# endif

#if defined(HAVE_SELINUX) || defined(PROTO)
/*
 * Copy security info from "from_file" to "to_file".
 */
    void
mch_copy_sec(char_u *from_file, char_u *to_file)
{
    if (from_file == NULL)
	return;

    if (selinux_enabled == -1)
	selinux_enabled = is_selinux_enabled();

    if (selinux_enabled <= 0)
	return;

    // Use "char *" instead of "security_context_t" to avoid a deprecation
    // warning.
    char *from_context = NULL;
    char *to_context = NULL;

    if (getfilecon((char *)from_file, &from_context) < 0)
    {
	// If the filesystem doesn't support extended attributes,
	// the original had no special security context and the
	// target cannot have one either.
	if (errno == EOPNOTSUPP)
	    return;

	msg_puts(_("\nCould not get security context for "));
	msg_outtrans(from_file);
	msg_putchar('\n');
	return;
    }
    if (getfilecon((char *)to_file, &to_context) < 0)
    {
	msg_puts(_("\nCould not get security context for "));
	msg_outtrans(to_file);
	msg_putchar('\n');
	freecon (from_context);
	return ;
    }
    if (strcmp(from_context, to_context) != 0)
    {
	if (setfilecon((char *)to_file, from_context) < 0)
	{
	    msg_puts(_("\nCould not set security context for "));
	    msg_outtrans(to_file);
	    msg_putchar('\n');
	}
    }
    freecon(to_context);
    freecon(from_context);
}
#endif // HAVE_SELINUX

#if defined(HAVE_SMACK) && !defined(PROTO)
/*
 * Copy security info from "from_file" to "to_file".
 */
    void
mch_copy_sec(char_u *from_file, char_u *to_file)
{
    static const char * const smack_copied_attributes[] =
	{
	    XATTR_NAME_SMACK,
	    XATTR_NAME_SMACKEXEC,
	    XATTR_NAME_SMACKMMAP
	};

    char	buffer[SMACK_LABEL_LEN];
    const char	*name;
    int		index;
    int		ret;
    ssize_t	size;

    if (from_file == NULL)
	return;

    size = listxattr((char *)from_file, NULL, 0);
    // not supported or no attributes to copy
    if (size <= 0)
	return;

    for (index = 0 ; index < (int)(sizeof(smack_copied_attributes)
			      / sizeof(smack_copied_attributes)[0]) ; index++)
    {
	// get the name of the attribute to copy
	name = smack_copied_attributes[index];

	// get the value of the attribute in buffer
	size = getxattr((char*)from_file, name, buffer, sizeof(buffer));
	if (size >= 0)
	{
	    // copy the attribute value of buffer
	    ret = setxattr((char*)to_file, name, buffer, (size_t)size, 0);
	    if (ret < 0)
	    {
		vim_snprintf((char *)IObuff, IOSIZE,
			_("Could not set security context %s for %s"),
			name, to_file);
		msg_outtrans(IObuff);
		msg_putchar('\n');
	    }
	}
	else
	{
	    // what reason of not having the attribute value?
	    switch (errno)
	    {
		case ENOTSUP:
		    // extended attributes aren't supported or enabled
		    // should a message be echoed? not sure...
		    return; // leave because it isn't useful to continue

		case ERANGE:
		default:
		    // no enough size OR unexpected error
		     vim_snprintf((char *)IObuff, IOSIZE,
			    _("Could not get security context %s for %s. Removing it!"),
			    name, from_file);
		    msg_puts((char *)IObuff);
		    msg_putchar('\n');
		    // FALLTHROUGH to remove the attribute

		case ENODATA:
		    // no attribute of this name
		    ret = removexattr((char*)to_file, name);
		    // Silently ignore errors, apparently this happens when
		    // smack is not actually being used.
		    break;
	    }
	}
    }
}
#endif // HAVE_SMACK

#ifdef FEAT_XATTR
/*
 * Copy extended attributes from_file to to_file
 */
    void
mch_copy_xattr(char_u *from_file, char_u *to_file)
{
    char	*xattr_buf;
    ssize_t	size;
    ssize_t	tsize;
    ssize_t	keylen, vallen, max_vallen = 0;
    char	*key;
    char	*val = NULL;
    char	*errmsg = NULL;

    if (from_file == NULL)
	return;

    // get the length of the extended attributes
    size = listxattr((char *)from_file, NULL, 0);
    // not supported or no attributes to copy
    if (size <= 0)
	return;
    xattr_buf = (char*)alloc(size);
    if (xattr_buf == NULL)
	return;
    size = listxattr((char *)from_file, xattr_buf, size);
    tsize = size;

    errno = 0;

    for (int round = 0; round < 2; round++)
    {

	key = xattr_buf;
	if (round == 1)
	    size = tsize;

	while (size > 0)
	{
	    vallen = getxattr((char *)from_file, key,
		    val, round ? max_vallen : 0);
	    // only set the attribute in the second round
	    if (vallen >= 0 && round &&
		setxattr((char *)to_file, key, val, vallen, 0) == 0)
		;
	    else if (errno)
	    {
		switch (errno)
		{
		    case E2BIG:
			errmsg = e_xattr_e2big;
			goto error_exit;
		    case ENOTSUP:
		    case EACCES:
		    case EPERM:
			break;
		    case ERANGE:
			errmsg = e_xattr_erange;
			goto error_exit;
		    default:
			errmsg = e_xattr_other;
			goto error_exit;
		}
	    }

	    if (round == 0 && vallen > max_vallen)
		max_vallen = vallen;

	    // add one for terminating null
	    keylen = STRLEN(key) + 1;
	    size -= keylen;
	    key += keylen;
	}
	if (round)
	    break;

	val = (char*)alloc(max_vallen + 1);
	if (val == NULL)
	    goto error_exit;

    }
error_exit:
    vim_free(xattr_buf);
    vim_free(val);

    if (errmsg != NULL)
	emsg(_(errmsg));
}
#endif

/*
 * Return a pointer to the ACL of file "fname" in allocated memory.
 * Return NULL if the ACL is not available for whatever reason.
 */
    vim_acl_T
mch_get_acl(char_u *fname UNUSED)
{
    vim_acl_T	ret = NULL;
#ifdef HAVE_POSIX_ACL
    ret = (vim_acl_T)acl_get_file((char *)fname, ACL_TYPE_ACCESS);
#else
#ifdef HAVE_SOLARIS_ZFS_ACL
    acl_t *aclent;

    if (acl_get((char *)fname, 0, &aclent) < 0)
	return NULL;
    ret = (vim_acl_T)aclent;
#else
#ifdef HAVE_SOLARIS_ACL
    vim_acl_solaris_T   *aclent;

    aclent = malloc(sizeof(vim_acl_solaris_T));
    if ((aclent->acl_cnt = acl((char *)fname, GETACLCNT, 0, NULL)) < 0)
    {
	free(aclent);
	return NULL;
    }
    aclent->acl_entry = malloc(aclent->acl_cnt * sizeof(aclent_t));
    if (acl((char *)fname, GETACL, aclent->acl_cnt, aclent->acl_entry) < 0)
    {
	free(aclent->acl_entry);
	free(aclent);
	return NULL;
    }
    ret = (vim_acl_T)aclent;
#else
#if defined(HAVE_AIX_ACL)
    int		aclsize;
    struct acl *aclent;

    aclsize = sizeof(struct acl);
    aclent = malloc(aclsize);
    if (statacl((char *)fname, STX_NORMAL, aclent, aclsize) < 0)
    {
	if (errno == ENOSPC)
	{
	    aclsize = aclent->acl_len;
	    aclent = realloc(aclent, aclsize);
	    if (statacl((char *)fname, STX_NORMAL, aclent, aclsize) < 0)
	    {
		free(aclent);
		return NULL;
	    }
	}
	else
	{
	    free(aclent);
	    return NULL;
	}
    }
    ret = (vim_acl_T)aclent;
#endif // HAVE_AIX_ACL
#endif // HAVE_SOLARIS_ACL
#endif // HAVE_SOLARIS_ZFS_ACL
#endif // HAVE_POSIX_ACL
    return ret;
}

/*
 * Set the ACL of file "fname" to "acl" (unless it's NULL).
 */
    void
mch_set_acl(char_u *fname UNUSED, vim_acl_T aclent)
{
    if (aclent == NULL)
	return;
#ifdef HAVE_POSIX_ACL
    acl_set_file((char *)fname, ACL_TYPE_ACCESS, (acl_t)aclent);
#else
#ifdef HAVE_SOLARIS_ZFS_ACL
    acl_set((char *)fname, (acl_t *)aclent);
#else
#ifdef HAVE_SOLARIS_ACL
    acl((char *)fname, SETACL, ((vim_acl_solaris_T *)aclent)->acl_cnt,
	    ((vim_acl_solaris_T *)aclent)->acl_entry);
#else
#ifdef HAVE_AIX_ACL
    chacl((char *)fname, aclent, ((struct acl *)aclent)->acl_len);
#endif // HAVE_AIX_ACL
#endif // HAVE_SOLARIS_ACL
#endif // HAVE_SOLARIS_ZFS_ACL
#endif // HAVE_POSIX_ACL
}

    void
mch_free_acl(vim_acl_T aclent)
{
    if (aclent == NULL)
	return;
#ifdef HAVE_POSIX_ACL
    acl_free((acl_t)aclent);
#else
#ifdef HAVE_SOLARIS_ZFS_ACL
    acl_free((acl_t *)aclent);
#else
#ifdef HAVE_SOLARIS_ACL
    free(((vim_acl_solaris_T *)aclent)->acl_entry);
    free(aclent);
#else
#ifdef HAVE_AIX_ACL
    free(aclent);
#endif // HAVE_AIX_ACL
#endif // HAVE_SOLARIS_ACL
#endif // HAVE_SOLARIS_ZFS_ACL
#endif // HAVE_POSIX_ACL
}
#endif

/*
 * Set hidden flag for "name".
 */
    void
mch_hide(char_u *name UNUSED)
{
    // can't hide a file
}

/*
 * return TRUE if "name" is a directory or a symlink to a directory
 * return FALSE if "name" is not a directory
 * return FALSE for error
 */
    int
mch_isdir(char_u *name)
{
    struct stat statb;

    if (*name == NUL)	    // Some stat()s don't flag "" as an error.
	return FALSE;
    if (stat((char *)name, &statb))
	return FALSE;
    return (S_ISDIR(statb.st_mode) ? TRUE : FALSE);
}

/*
 * return TRUE if "name" is a directory, NOT a symlink to a directory
 * return FALSE if "name" is not a directory
 * return FALSE for error
 */
    int
mch_isrealdir(char_u *name)
{
    struct stat statb;

    if (*name == NUL)	    // Some stat()s don't flag "" as an error.
	return FALSE;
    if (mch_lstat((char *)name, &statb))
	return FALSE;
    return (S_ISDIR(statb.st_mode) ? TRUE : FALSE);
}

/*
 * Return 1 if "name" is an executable file, 0 if not or it doesn't exist.
 */
    static int
executable_file(char_u *name)
{
    struct stat	st;

    if (stat((char *)name, &st))
	return 0;
#ifdef VMS
    // Like on Unix system file can have executable rights but not necessarily
    // be an executable, but on Unix is not a default for an ordinary file to
    // have an executable flag - on VMS it is in most cases.
    // Therefore, this check does not have any sense - let keep us to the
    // conventions instead:
    // *.COM and *.EXE files are the executables - the rest are not. This is
    // not ideal but better than it was.
    int vms_executable = 0;
    if (S_ISREG(st.st_mode) && mch_access((char *)name, X_OK) == 0)
    {
	if (strstr(vms_tolower((char*)name),".exe") != NULL
		|| strstr(vms_tolower((char*)name),".com")!= NULL)
	    vms_executable = 1;
    }
    return vms_executable;
#else
    return S_ISREG(st.st_mode) && mch_access((char *)name, X_OK) == 0;
#endif
}

/*
 * Return TRUE if "name" can be found in $PATH and executed, FALSE if not.
 * If "use_path" is FALSE only check if "name" is executable.
 * Return -1 if unknown.
 */
    int
mch_can_exe(char_u *name, char_u **path, int use_path)
{
    char_u	*buf;
    char_u	*p, *e;
    int		retval;

    // When "use_path" is false and if it's an absolute or relative path don't
    // need to use $PATH.
    if (!use_path || gettail(name) != name)
    {
	// There must be a path separator, files in the current directory
	// can't be executed.
	if ((use_path || gettail(name) != name) && executable_file(name))
	{
	    if (path != NULL)
	    {
		if (name[0] != '/')
		    *path = FullName_save(name, TRUE);
		else
		    *path = vim_strsave(name);
	    }
	    return TRUE;
	}
	return FALSE;
    }

    p = (char_u *)getenv("PATH");
    if (p == NULL || *p == NUL)
	return -1;
    buf = alloc(STRLEN(name) + STRLEN(p) + 2);
    if (buf == NULL)
	return -1;

    /*
     * Walk through all entries in $PATH to check if "name" exists there and
     * is an executable file.
     */
    for (;;)
    {
	e = (char_u *)strchr((char *)p, ':');
	if (e == NULL)
	    e = p + STRLEN(p);
	if (e - p <= 1)		// empty entry means current dir
	    STRCPY(buf, "./");
	else
	{
	    vim_strncpy(buf, p, e - p);
	    add_pathsep(buf);
	}
	STRCAT(buf, name);
	retval = executable_file(buf);
	if (retval == 1)
	{
	    if (path != NULL)
	    {
		if (buf[0] != '/')
		    *path = FullName_save(buf, TRUE);
		else
		    *path = vim_strsave(buf);
	    }
	    break;
	}

	if (*e != ':')
	    break;
	p = e + 1;
    }

    vim_free(buf);
    return retval;
}

/*
 * Check what "name" is:
 * NODE_NORMAL: file or directory (or doesn't exist)
 * NODE_WRITABLE: writable device, socket, fifo, etc.
 * NODE_OTHER: non-writable things
 */
    int
mch_nodetype(char_u *name)
{
    struct stat	st;

    if (stat((char *)name, &st))
	return NODE_NORMAL;
    if (S_ISREG(st.st_mode) || S_ISDIR(st.st_mode))
	return NODE_NORMAL;
    if (S_ISBLK(st.st_mode))	// block device isn't writable
	return NODE_OTHER;
    // Everything else is writable?
    return NODE_WRITABLE;
}

    void
mch_early_init(void)
{
#ifdef HAVE_CHECK_STACK_GROWTH
    int			i;

    check_stack_growth((char *)&i);

# ifdef HAVE_STACK_LIMIT
    get_stack_limit();
# endif

#endif

    /*
     * Setup an alternative stack for signals.  Helps to catch signals when
     * running out of stack space.
     * Use of sigaltstack() is preferred, it's more portable.
     * Ignore any errors.
     */
#if defined(HAVE_SIGALTSTACK) || defined(HAVE_SIGSTACK)
    signal_stack = alloc(get_signal_stack_size());
    init_signal_stack();
#endif
}

#if defined(EXITFREE) || defined(PROTO)
    void
mch_free_mem(void)
{
# if defined(FEAT_CLIPBOARD) && defined(FEAT_X11)
    if (clip_star.owned)
	clip_lose_selection(&clip_star);
    if (clip_plus.owned)
	clip_lose_selection(&clip_plus);
# endif
# if defined(FEAT_X11) && defined(FEAT_XCLIPBOARD)
    if (xterm_Shell != (Widget)0)
	XtDestroyWidget(xterm_Shell);
#  ifndef LESSTIF_VERSION
    // Lesstif crashes here, lose some memory
    if (xterm_dpy != NULL)
	XtCloseDisplay(xterm_dpy);
    if (app_context != (XtAppContext)NULL)
    {
	XtDestroyApplicationContext(app_context);
#   ifdef FEAT_X11
	x11_display = NULL; // freed by XtDestroyApplicationContext()
#   endif
    }
#  endif
# endif
# if defined(FEAT_X11)
    if (x11_display != NULL
#  ifdef FEAT_XCLIPBOARD
	    && x11_display != xterm_dpy
#  endif
	    )
	XCloseDisplay(x11_display);
# endif
# if defined(HAVE_SIGALTSTACK) || defined(HAVE_SIGSTACK)
    VIM_CLEAR(signal_stack);
# endif
    vim_free(oldtitle);
    vim_free(oldicon);
}
#endif

/*
 * Output a newline when exiting.
 * Make sure the newline goes to the same stream as the text.
 */
    static void
exit_scroll(void)
{
    if (silent_mode)
	return;
    if (newline_on_exit || msg_didout)
    {
	if (msg_use_printf())
	{
	    if (info_message)
		mch_msg("\n");
	    else
		mch_errmsg("\r\n");
	}
	else
	    out_char('\n');
    }
    else if (!is_not_a_term())
    {
	restore_cterm_colors();		// get original colors back
	msg_clr_eos_force();		// clear the rest of the display
	windgoto((int)Rows - 1, 0);	// may have moved the cursor
    }
}

#ifdef USE_GCOV_FLUSH
# if (defined(__GNUC__) \
	    && ((__GNUC__ == 11 && __GNUC_MINOR__ >= 1) || (__GNUC__ >= 12))) \
	|| (defined(__clang__) && (__clang_major__ >= 12))
extern void __gcov_dump(void);
extern void __gcov_reset(void);
#  define __gcov_flush() do { __gcov_dump(); __gcov_reset(); } while (0)
# else
extern void __gcov_flush(void);
# endif
#endif

    void
mch_exit(int r)
{
    exiting = TRUE;

#if defined(FEAT_X11) && defined(FEAT_CLIPBOARD)
    x11_export_final_selection();
#endif

#ifdef FEAT_GUI
    if (!gui.in_use)
#endif
    {
	settmode(TMODE_COOK);
	if (!is_not_a_term())
	{
	    // restore xterm title and icon name
	    mch_restore_title(SAVE_RESTORE_BOTH);
	    term_pop_title(SAVE_RESTORE_BOTH);
	}

	/*
	 * When t_ti is not empty but it doesn't cause swapping terminal
	 * pages, need to output a newline when msg_didout is set.  But when
	 * t_ti does swap pages it should not go to the shell page.  Do this
	 * before stoptermcap().
	 */
	if (swapping_screen() && !newline_on_exit)
	    exit_scroll();

	// Stop termcap: May need to check for T_CRV response, which
	// requires RAW mode.
	stoptermcap();

	/*
	 * A newline is only required after a message in the alternate screen.
	 * This is set to TRUE by wait_return().
	 */
	if (!swapping_screen() || newline_on_exit)
	    exit_scroll();

	// Cursor may have been switched off without calling starttermcap()
	// when doing "vim -u vimrc" and vimrc contains ":q".
	if (full_screen)
	    cursor_on();
    }
    out_flush();
    ml_close_all(TRUE);		// remove all memfiles

#ifdef USE_GCOV_FLUSH
    // Flush coverage info before possibly being killed by a deadly signal.
    __gcov_flush();
#endif

    may_core_dump();
#ifdef FEAT_GUI
    if (gui.in_use)
	gui_exit(r);
#endif

#ifdef MACOS_CONVERT
    mac_conv_cleanup();
#endif

#ifdef __QNX__
    // A core dump won't be created if the signal handler
    // doesn't return, so we can't call exit()
    if (deadly_signal != 0)
	return;
#endif

#ifdef FEAT_NETBEANS_INTG
    netbeans_send_disconnect();
#endif

#ifdef EXITFREE
    free_all_mem();
#endif

    exit(r);
}

    static void
may_core_dump(void)
{
    if (deadly_signal != 0)
    {
	mch_signal(deadly_signal, SIG_DFL);
	kill(getpid(), deadly_signal);	// Die using the signal we caught
    }
}

#ifndef VMS

/*
 * Get the file descriptor to use for tty operations.
 */
    static int
get_tty_fd(int fd)
{
    int		tty_fd = fd;

#if defined(HAVE_SVR4_PTYS) && defined(SUN_SYSTEM)
    // On SunOS: Get the terminal parameters from "fd", or the slave device of
    // "fd" when it is a master device.
    if (mch_isatty(fd) > 1)
    {
	char *name;

	name = ptsname(fd);
	if (name == NULL)
	    return -1;

	tty_fd = open(name, O_RDONLY | O_NOCTTY | O_EXTRA, 0);
	if (tty_fd < 0)
	    return -1;
    }
#endif
    return tty_fd;
}

    static int
mch_tcgetattr(int fd, void *term)
{
    int		tty_fd;
    int		retval = -1;

    tty_fd = get_tty_fd(fd);
    if (tty_fd < 0)
	return -1;

#ifdef NEW_TTY_SYSTEM
# ifdef HAVE_TERMIOS_H
    retval = tcgetattr(tty_fd, (struct termios *)term);
# else
    retval = ioctl(tty_fd, TCGETA, (struct termio *)term);
# endif
#else
    // for "old" tty systems
    retval = ioctl(tty_fd, TIOCGETP, (struct sgttyb *)term);
#endif
    if (tty_fd != fd)
	close(tty_fd);
    return retval;
}

    void
mch_settmode(tmode_T tmode)
{
    static int first = TRUE;

#ifdef NEW_TTY_SYSTEM
# ifdef HAVE_TERMIOS_H
    static struct termios told;
	   struct termios tnew;
# else
    static struct termio told;
	   struct termio tnew;
# endif

    if (first)
    {
	first = FALSE;
	mch_tcgetattr(read_cmd_fd, &told);
    }

    tnew = told;
    if (tmode == TMODE_RAW)
    {
	// ~ICRNL enables typing ^V^M
	// ~IXON disables CTRL-S stopping output, so that it can be mapped.
	tnew.c_iflag &= ~(ICRNL | IXON);
	tnew.c_lflag &= ~(ICANON | ECHO | ISIG | ECHOE
# if defined(IEXTEN)
		    | IEXTEN	    // IEXTEN enables typing ^V on SOLARIS
# endif
				);
# ifdef ONLCR
	// Don't map NL -> CR NL, we do it ourselves.
	// Also disable expanding tabs if possible.
#  ifdef XTABS
	tnew.c_oflag &= ~(ONLCR | XTABS);
#  else
#   ifdef TAB3
	tnew.c_oflag &= ~(ONLCR | TAB3);
#   else
	tnew.c_oflag &= ~ONLCR;
#   endif
#  endif
# endif
	tnew.c_cc[VMIN] = 1;		// return after 1 char
	tnew.c_cc[VTIME] = 0;		// don't wait
    }
    else if (tmode == TMODE_SLEEP)
    {
	// Also reset ICANON here, otherwise on Solaris select() won't see
	// typeahead characters.
	tnew.c_lflag &= ~(ICANON | ECHO);
	tnew.c_cc[VMIN] = 1;		// return after 1 char
	tnew.c_cc[VTIME] = 0;		// don't wait
    }

# if defined(HAVE_TERMIOS_H)
    {
	int	n = 10;

	// A signal may cause tcsetattr() to fail (e.g., SIGCONT).  Retry a
	// few times.
	while (tcsetattr(read_cmd_fd, TCSANOW, &tnew) == -1
						   && errno == EINTR && n > 0)
	    --n;
    }
# else
    ioctl(read_cmd_fd, TCSETA, &tnew);
# endif

#else
    /*
     * for "old" tty systems
     */
# ifndef TIOCSETN
#  define TIOCSETN TIOCSETP	// for hpux 9.0
# endif
    static struct sgttyb ttybold;
	   struct sgttyb ttybnew;

    if (first)
    {
	first = FALSE;
	mch_tcgetattr(read_cmd_fd, &ttybold);
    }

    ttybnew = ttybold;
    if (tmode == TMODE_RAW)
    {
	ttybnew.sg_flags &= ~(CRMOD | ECHO);
	ttybnew.sg_flags |= RAW;
    }
    else if (tmode == TMODE_SLEEP)
	ttybnew.sg_flags &= ~(ECHO);
    ioctl(read_cmd_fd, TIOCSETN, &ttybnew);
#endif
    mch_cur_tmode = tmode;
}

/*
 * Try to get the code for "t_kb" from the stty setting
 *
 * Even if termcap claims a backspace key, the user's setting *should*
 * prevail.  stty knows more about reality than termcap does, and if
 * somebody's usual erase key is DEL (which, for most BSD users, it will
 * be), they're going to get really annoyed if their erase key starts
 * doing forward deletes for no reason. (Eric Fischer)
 */
    void
get_stty(void)
{
    ttyinfo_T	info;
    char_u	buf[2];
    char_u	*p;

    if (get_tty_info(read_cmd_fd, &info) != OK)
	return;

    intr_char = info.interrupt;
    buf[0] = info.backspace;
    buf[1] = NUL;
    add_termcode((char_u *)"kb", buf, FALSE);

    // If <BS> and <DEL> are now the same, redefine <DEL>.
    p = find_termcode((char_u *)"kD");
    if (p != NULL && p[0] == buf[0] && p[1] == buf[1])
	do_fixdel(NULL);
}

/*
 * Obtain the characters that Backspace and Enter produce on "fd".
 * Returns OK or FAIL.
 */
    int
get_tty_info(int fd, ttyinfo_T *info)
{
#ifdef NEW_TTY_SYSTEM
# ifdef HAVE_TERMIOS_H
    struct termios keys;
# else
    struct termio keys;
# endif

    if (mch_tcgetattr(fd, &keys) != -1)
    {
	info->backspace = keys.c_cc[VERASE];
	info->interrupt = keys.c_cc[VINTR];
	if (keys.c_iflag & ICRNL)
	    info->enter = NL;
	else
	    info->enter = CAR;
	if (keys.c_oflag & ONLCR)
	    info->nl_does_cr = TRUE;
	else
	    info->nl_does_cr = FALSE;
	return OK;
    }
#else
    // for "old" tty systems
    struct sgttyb keys;

    if (mch_tcgetattr(fd, &keys) != -1)
    {
	info->backspace = keys.sg_erase;
	info->interrupt = keys.sg_kill;
	info->enter = CAR;
	info->nl_does_cr = TRUE;
	return OK;
    }
#endif
    return FAIL;
}

#endif // VMS

static int	mouse_ison = FALSE;

/*
 * Set mouse clicks on or off and possible enable mouse movement events.
 */
    void
mch_setmouse(int on)
{
#ifdef FEAT_BEVAL_TERM
    static int	bevalterm_ison = FALSE;
#endif
    int		xterm_mouse_vers;

#if defined(FEAT_X11) && defined(FEAT_XCLIPBOARD)
    if (!on)
	// Make sure not tracing mouse movements.  Important when a button-down
	// was received but no release yet.
	stop_xterm_trace();
#endif

    if (on == mouse_ison
#ifdef FEAT_BEVAL_TERM
	    && p_bevalterm == bevalterm_ison
#endif
	    )
	// return quickly if nothing to do
	return;

    xterm_mouse_vers = use_xterm_mouse();

#ifdef FEAT_MOUSE_URXVT
    if (ttym_flags == TTYM_URXVT)
    {
	out_str_nf((char_u *)(on ? "\033[?1015h" : "\033[?1015l"));
	mouse_ison = on;
    }
#endif

    if (T_CXM != NULL && *T_CXM != NUL)
    {
	term_enable_mouse(on);
    }
    else if (ttym_flags == TTYM_SGR)
    {
	// SGR mode supports columns above 223
	out_str_nf((char_u *)(on ? "\033[?1006h" : "\033[?1006l"));
	mouse_ison = on;
    }

#ifdef FEAT_BEVAL_TERM
    if (bevalterm_ison != (p_bevalterm && on))
    {
	bevalterm_ison = (p_bevalterm && on);
	if (xterm_mouse_vers > 1 && !bevalterm_ison)
	    // disable mouse movement events, enabling is below
	    out_str_nf((char_u *)("\033[?1003l"));
    }
#endif

    if (xterm_mouse_vers > 0)
    {
	if (on)	// enable mouse events, use mouse tracking if available
	    out_str_nf((char_u *)
		       (xterm_mouse_vers > 1
			? (
#ifdef FEAT_BEVAL_TERM
			    bevalterm_ison ? "\033[?1003h" :
#endif
			      "\033[?1002h")
			: "\033[?1000h"));
	else	// disable mouse events, could probably always send the same
	    out_str_nf((char_u *)
		       (xterm_mouse_vers > 1 ? "\033[?1002l" : "\033[?1000l"));
	mouse_ison = on;
    }

#ifdef FEAT_MOUSE_DEC
    else if (ttym_flags == TTYM_DEC)
    {
	if (on)	// enable mouse events
	    out_str_nf((char_u *)"\033[1;2'z\033[1;3'{");
	else	// disable mouse events
	    out_str_nf((char_u *)"\033['z");
	mouse_ison = on;
    }
#endif

#ifdef FEAT_MOUSE_GPM
    else
    {
	if (on)
	{
	    if (gpm_open())
		mouse_ison = TRUE;
	}
	else
	{
	    gpm_close();
	    mouse_ison = FALSE;
	}
    }
#endif

#ifdef FEAT_SYSMOUSE
    else
    {
	if (on)
	{
	    if (sysmouse_open() == OK)
		mouse_ison = TRUE;
	}
	else
	{
	    sysmouse_close();
	    mouse_ison = FALSE;
	}
    }
#endif

#ifdef FEAT_MOUSE_JSB
    else
    {
	if (on)
	{
	    // D - Enable Mouse up/down messages
	    // L - Enable Left Button Reporting
	    // M - Enable Middle Button Reporting
	    // R - Enable Right Button Reporting
	    // K - Enable SHIFT and CTRL key Reporting
	    // + - Enable Advanced messaging of mouse moves and up/down messages
	    // Q - Quiet No Ack
	    // # - Numeric value of mouse pointer required
	    //	  0 = Multiview 2000 cursor, used as standard
	    //	  1 = Windows Arrow
	    //	  2 = Windows I Beam
	    //	  3 = Windows Hour Glass
	    //	  4 = Windows Cross Hair
	    //	  5 = Windows UP Arrow
# ifdef JSBTERM_MOUSE_NONADVANCED
	    // Disables full feedback of pointer movements
	    out_str_nf((char_u *)"\033[0~ZwLMRK1Q\033\\");
# else
	    out_str_nf((char_u *)"\033[0~ZwLMRK+1Q\033\\");
# endif
	    mouse_ison = TRUE;
	}
	else
	{
	    out_str_nf((char_u *)"\033[0~ZwQ\033\\");
	    mouse_ison = FALSE;
	}
    }
#endif
#ifdef FEAT_MOUSE_PTERM
    else
    {
	// 1 = button press, 6 = release, 7 = drag, 1h...9l = right button
	if (on)
	    out_str_nf("\033[>1h\033[>6h\033[>7h\033[>1h\033[>9l");
	else
	    out_str_nf("\033[>1l\033[>6l\033[>7l\033[>1l\033[>9h");
	mouse_ison = on;
    }
#endif
}

#if defined(FEAT_BEVAL_TERM) || defined(PROTO)
/*
 * Called when 'balloonevalterm' changed.
 */
    void
mch_bevalterm_changed(void)
{
    mch_setmouse(mouse_ison);
}
#endif

/*
 * Set the mouse termcode, depending on the 'term' and 'ttymouse' options.
 */
    void
check_mouse_termcode(void)
{
# ifdef FEAT_MOUSE_XTERM
    if (use_xterm_mouse()
# ifdef FEAT_MOUSE_URXVT
	    && use_xterm_mouse() != 3
# endif
#  ifdef FEAT_GUI
	    && !gui.in_use
#  endif
	    )
    {
	set_mouse_termcode(KS_MOUSE, (char_u *)(term_is_8bit(T_NAME)
							? "\233M" : "\033[M"));
	if (*p_mouse != NUL)
	{
	    // force mouse off and maybe on to send possibly new mouse
	    // activation sequence to the xterm, with(out) drag tracing.
	    mch_setmouse(FALSE);
	    setmouse();
	}
    }
    else
	del_mouse_termcode(KS_MOUSE);
# endif

# ifdef FEAT_MOUSE_GPM
    if (!use_xterm_mouse()
#  ifdef FEAT_GUI
	    && !gui.in_use
#  endif
	    )
	set_mouse_termcode(KS_GPM_MOUSE, (char_u *)"\033MG");
    else
	del_mouse_termcode(KS_GPM_MOUSE);
# endif

# ifdef FEAT_SYSMOUSE
    if (!use_xterm_mouse()
#  ifdef FEAT_GUI
	    && !gui.in_use
#  endif
	    )
	set_mouse_termcode(KS_MOUSE, (char_u *)"\033MS");
# endif

# ifdef FEAT_MOUSE_JSB
    // Conflicts with xterm mouse: "\033[" and "\033[M" ???
    if (!use_xterm_mouse()
#  ifdef FEAT_GUI
	    && !gui.in_use
#  endif
	    )
	set_mouse_termcode(KS_JSBTERM_MOUSE, (char_u *)"\033[0~zw");
    else
	del_mouse_termcode(KS_JSBTERM_MOUSE);
# endif

# ifdef FEAT_MOUSE_NET
    // There is no conflict, but one may type "ESC }" from Insert mode.  Don't
    // define it in the GUI or when using an xterm.
    if (!use_xterm_mouse()
#  ifdef FEAT_GUI
	    && !gui.in_use
#  endif
	    )
	set_mouse_termcode(KS_NETTERM_MOUSE, (char_u *)"\033}");
    else
	del_mouse_termcode(KS_NETTERM_MOUSE);
# endif

# ifdef FEAT_MOUSE_DEC
    // Conflicts with xterm mouse: "\033[" and "\033[M"
    if (!use_xterm_mouse()
#  ifdef FEAT_GUI
	    && !gui.in_use
#  endif
	    )
	set_mouse_termcode(KS_DEC_MOUSE, (char_u *)(term_is_8bit(T_NAME)
							  ? "\233" : "\033["));
    else
	del_mouse_termcode(KS_DEC_MOUSE);
# endif
# ifdef FEAT_MOUSE_PTERM
    // same conflict as the dec mouse
    if (!use_xterm_mouse()
#  ifdef FEAT_GUI
	    && !gui.in_use
#  endif
	    )
	set_mouse_termcode(KS_PTERM_MOUSE, (char_u *)"\033[");
    else
	del_mouse_termcode(KS_PTERM_MOUSE);
# endif
# ifdef FEAT_MOUSE_URXVT
    if (use_xterm_mouse() == 3
#  ifdef FEAT_GUI
	    && !gui.in_use
#  endif
	    )
    {
	set_mouse_termcode(KS_URXVT_MOUSE, (char_u *)(term_is_8bit(T_NAME)
						      ? "\233*M" : "\033[*M"));

	if (*p_mouse != NUL)
	{
	    mch_setmouse(FALSE);
	    setmouse();
	}
    }
    else
	del_mouse_termcode(KS_URXVT_MOUSE);
# endif
    if (use_xterm_mouse() == 4
# ifdef FEAT_GUI
	    && !gui.in_use
# endif
	    )
    {
	set_mouse_termcode(KS_SGR_MOUSE, (char_u *)(term_is_8bit(T_NAME)
						    ? "\233<*M" : "\033[<*M"));

	set_mouse_termcode(KS_SGR_MOUSE_RELEASE, (char_u *)(term_is_8bit(T_NAME)
						    ? "\233<*m" : "\033[<*m"));

	if (*p_mouse != NUL)
	{
	    mch_setmouse(FALSE);
	    setmouse();
	}
    }
    else
    {
	del_mouse_termcode(KS_SGR_MOUSE);
	del_mouse_termcode(KS_SGR_MOUSE_RELEASE);
    }
}

#ifndef VMS

/*
 * Try to get the current window size:
 * 1. with an ioctl(), most accurate method
 * 2. from the environment variables LINES and COLUMNS
 * 3. from the termcap
 * 4. keep using the old values
 * Return OK when size could be determined, FAIL otherwise.
 */
    int
mch_get_shellsize(void)
{
    long	rows = 0;
    long	columns = 0;
    char_u	*p;

    /*
     * 1. try using an ioctl. It is the most accurate method.
     *
     * Try using TIOCGWINSZ first, some systems that have it also define
     * TIOCGSIZE but don't have a struct ttysize.
     */
# ifdef TIOCGWINSZ
    {
	struct winsize	ws;
	int fd = 1;

	// When stdout is not a tty, use stdin for the ioctl().
	if (!isatty(fd) && isatty(read_cmd_fd))
	    fd = read_cmd_fd;
	if (ioctl(fd, TIOCGWINSZ, &ws) == 0)
	{
	    columns = ws.ws_col;
	    rows = ws.ws_row;
#  ifdef FEAT_EVAL
	    ch_log(NULL, "Got size with TIOCGWINSZ: %ld x %ld", columns, rows);
#  endif
	}
    }
# else // TIOCGWINSZ
#  ifdef TIOCGSIZE
    {
	struct ttysize	ts;
	int fd = 1;

	// When stdout is not a tty, use stdin for the ioctl().
	if (!isatty(fd) && isatty(read_cmd_fd))
	    fd = read_cmd_fd;
	if (ioctl(fd, TIOCGSIZE, &ts) == 0)
	{
	    columns = ts.ts_cols;
	    rows = ts.ts_lines;
#  ifdef FEAT_EVAL
	    ch_log(NULL, "Got size with TIOCGSIZE: %ld x %ld", columns, rows);
#  endif
	}
    }
#  endif // TIOCGSIZE
# endif // TIOCGWINSZ

    /*
     * 2. get size from environment
     *    When being POSIX compliant ('|' flag in 'cpoptions') this overrules
     *    the ioctl() values!
     */
    if (columns == 0 || rows == 0 || vim_strchr(p_cpo, CPO_TSIZE) != NULL)
    {
	if ((p = (char_u *)getenv("LINES")))
	{
	    rows = atoi((char *)p);
#  ifdef FEAT_EVAL
	    ch_log(NULL, "Got 'lines' from $LINES: %ld", rows);
#  endif
	}
	if ((p = (char_u *)getenv("COLUMNS")))
	{
	    columns = atoi((char *)p);
#  ifdef FEAT_EVAL
	    ch_log(NULL, "Got 'columns' from $COLUMNS: %ld", columns);
#  endif
	}
    }

#ifdef HAVE_TGETENT
    /*
     * 3. try reading "co" and "li" entries from termcap
     */
    if (columns == 0 || rows == 0)
    {
	getlinecol(&columns, &rows);
# ifdef FEAT_EVAL
	ch_log(NULL, "Got size from termcap: %ld x %ld", columns, rows);
# endif
    }
#endif

    /*
     * 4. If everything fails, use the old values
     */
    if (columns <= 0 || rows <= 0)
	return FAIL;

    Rows = rows;
    Columns = columns;
    limit_screen_size();
    return OK;
}

#if defined(FEAT_TERMINAL) || defined(PROTO)
/*
 * Report the windows size "rows" and "cols" to tty "fd".
 */
    int
mch_report_winsize(int fd, int rows, int cols)
{
    int		tty_fd;
    int		retval = -1;

    tty_fd = get_tty_fd(fd);
    if (tty_fd < 0)
	return FAIL;

# if defined(TIOCSWINSZ)
    struct winsize ws;

    ws.ws_col = cols;
    ws.ws_row = rows;
    ws.ws_xpixel = cols * 5;
    ws.ws_ypixel = rows * 10;
    retval = ioctl(tty_fd, TIOCSWINSZ, &ws);
    ch_log(NULL, "ioctl(TIOCSWINSZ) %s", retval == 0 ? "success" : "failed");
# elif defined(TIOCSSIZE)
    struct ttysize ts;

    ts.ts_cols = cols;
    ts.ts_lines = rows;
    retval = ioctl(tty_fd, TIOCSSIZE, &ts);
    ch_log(NULL, "ioctl(TIOCSSIZE) %s", retval == 0 ? "success" : "failed");
# endif
    if (tty_fd != fd)
	close(tty_fd);
    return retval == 0 ? OK : FAIL;
}
#endif

/*
 * Try to set the window size to Rows and Columns.
 */
    void
mch_set_shellsize(void)
{
    if (*T_CWS)
    {
	/*
	 * NOTE: if you get an error here that term_set_winsize() is
	 * undefined, check the output of configure.  It could probably not
	 * find a ncurses, termcap or termlib library.
	 */
	term_set_winsize((int)Rows, (int)Columns);
	out_flush();
	screen_start();			// don't know where cursor is now
    }
}

#endif // VMS

/*
 * Rows and/or Columns has changed.
 */
    void
mch_new_shellsize(void)
{
    // Nothing to do.
}

/*
 * Wait for process "child" to end.
 * Return "child" if it exited properly, <= 0 on error.
 */
    static pid_t
wait4pid(pid_t child, waitstatus *status)
{
    pid_t wait_pid = 0;
    long delay_msec = 1;

    while (wait_pid != child)
    {
	// When compiled with Python threads are probably used, in which case
	// wait() sometimes hangs for no obvious reason.  Use waitpid()
	// instead and loop (like the GUI). Also needed for other interfaces,
	// they might call system().
# ifdef __NeXT__
	wait_pid = wait4(child, status, WNOHANG, (struct rusage *)0);
# else
	wait_pid = waitpid(child, status, WNOHANG);
# endif
	if (wait_pid == 0)
	{
	    // Wait for 1 to 10 msec before trying again.
	    mch_delay(delay_msec, MCH_DELAY_IGNOREINPUT | MCH_DELAY_SETTMODE);
	    if (++delay_msec > 10)
		delay_msec = 10;
	    continue;
	}
	if (wait_pid <= 0
# ifdef ECHILD
		&& errno == ECHILD
# endif
	   )
	    break;
    }
    return wait_pid;
}

#if !defined(USE_SYSTEM) || defined(FEAT_JOB_CHANNEL)
/*
 * Set the environment for a child process.
 */
    static void
set_child_environment(
	long	rows,
	long	columns,
	char	*term,
	int	is_terminal UNUSED)
{
# ifdef HAVE_SETENV
    char	envbuf[50];
# else
    static char	envbuf_Term[30];
    static char	envbuf_Rows[20];
    static char	envbuf_Lines[20];
    static char	envbuf_Columns[20];
    static char	envbuf_Colors[20];
#  ifdef FEAT_TERMINAL
    static char	envbuf_Version[20];
#  endif
#  ifdef FEAT_CLIENTSERVER
    static char	envbuf_Servername[60];
#  endif
# endif

# ifdef HAVE_SETENV
    setenv("TERM", term, 1);
    sprintf((char *)envbuf, "%ld", rows);
    setenv("ROWS", (char *)envbuf, 1);
    sprintf((char *)envbuf, "%ld", rows);
    setenv("LINES", (char *)envbuf, 1);
    sprintf((char *)envbuf, "%ld", columns);
    setenv("COLUMNS", (char *)envbuf, 1);
    sprintf((char *)envbuf, "%d", t_colors);
    setenv("COLORS", (char *)envbuf, 1);
#  ifdef FEAT_TERMINAL
    if (is_terminal)
    {
	sprintf((char *)envbuf, "%ld",  (long)get_vim_var_nr(VV_VERSION));
	setenv("VIM_TERMINAL", (char *)envbuf, 1);
    }
#  endif
#  ifdef FEAT_CLIENTSERVER
    setenv("VIM_SERVERNAME", serverName == NULL ? "" : (char *)serverName, 1);
#  endif
# else
    /*
     * Putenv does not copy the string, it has to remain valid.
     * Use a static array to avoid losing allocated memory.
     * This won't work well when running multiple children...
     */
    vim_snprintf(envbuf_Term, sizeof(envbuf_Term), "TERM=%s", term);
    putenv(envbuf_Term);
    vim_snprintf(envbuf_Rows, sizeof(envbuf_Rows), "ROWS=%ld", rows);
    putenv(envbuf_Rows);
    vim_snprintf(envbuf_Lines, sizeof(envbuf_Lines), "LINES=%ld", rows);
    putenv(envbuf_Lines);
    vim_snprintf(envbuf_Columns, sizeof(envbuf_Columns),
						       "COLUMNS=%ld", columns);
    putenv(envbuf_Columns);
    vim_snprintf(envbuf_Colors, sizeof(envbuf_Colors), "COLORS=%ld", t_colors);
    putenv(envbuf_Colors);
#  ifdef FEAT_TERMINAL
    if (is_terminal)
    {
	vim_snprintf(envbuf_Version, sizeof(envbuf_Version),
			 "VIM_TERMINAL=%ld", (long)get_vim_var_nr(VV_VERSION));
	putenv(envbuf_Version);
    }
#  endif
#  ifdef FEAT_CLIENTSERVER
    vim_snprintf(envbuf_Servername, sizeof(envbuf_Servername),
	    "VIM_SERVERNAME=%s", serverName == NULL ? "" : (char *)serverName);
    putenv(envbuf_Servername);
#  endif
# endif
}

    static void
set_default_child_environment(int is_terminal)
{
    set_child_environment(Rows, Columns, "dumb", is_terminal);
}
#endif

#if defined(FEAT_GUI) || defined(FEAT_JOB_CHANNEL)
/*
 * Open a PTY, with FD for the master and slave side.
 * When failing "pty_master_fd" and "pty_slave_fd" are -1.
 * When successful both file descriptors are stored and the allocated pty name
 * is stored in both "*name1" and "*name2".
 */
    static void
open_pty(int *pty_master_fd, int *pty_slave_fd, char_u **name1, char_u **name2)
{
    char	*tty_name;

    if (name1 != NULL)
	*name1 = NULL;
    if (name2 != NULL)
	*name2 = NULL;

    *pty_master_fd = mch_openpty(&tty_name);	    // open pty
    if (*pty_master_fd < 0)
	return;

    // Leaving out O_NOCTTY may lead to waitpid() always returning
    // 0 on Mac OS X 10.7 thereby causing freezes. Let's assume
    // adding O_NOCTTY always works when defined.
#ifdef O_NOCTTY
    *pty_slave_fd = open(tty_name, O_RDWR | O_NOCTTY | O_EXTRA, 0);
#else
    *pty_slave_fd = open(tty_name, O_RDWR | O_EXTRA, 0);
#endif
    if (*pty_slave_fd < 0)
    {
	close(*pty_master_fd);
	*pty_master_fd = -1;
    }
    else
    {
	if (name1 != NULL)
	    *name1 = vim_strsave((char_u *)tty_name);
	if (name2 != NULL)
	    *name2 = vim_strsave((char_u *)tty_name);
    }
}
#endif

/*
 * Send SIGINT to a child process if "c" is an interrupt character.
 */
    static void
may_send_sigint(int c UNUSED, pid_t pid UNUSED, pid_t wpid UNUSED)
{
# ifdef SIGINT
    if (c == Ctrl_C || c == intr_char)
    {
#  ifdef HAVE_SETSID
	kill(-pid, SIGINT);
#  else
	kill(0, SIGINT);
#  endif
	if (wpid > 0)
	    kill(wpid, SIGINT);
    }
# endif
}

#if !defined(USE_SYSTEM) || defined(FEAT_TERMINAL) || defined(PROTO)

/*
 * Parse "cmd" and return the result in "argvp" which is an allocated array of
 * pointers, the last one is NULL.
 * The "sh_tofree" and "shcf_tofree" must be later freed by the caller.
 */
    int
unix_build_argv(
	char_u *cmd,
	char ***argvp,
	char_u **sh_tofree,
	char_u **shcf_tofree)
{
    char	**argv = NULL;
    int		argc;

    *sh_tofree = vim_strsave(p_sh);
    if (*sh_tofree == NULL)		// out of memory
	return FAIL;

    if (mch_parse_cmd(*sh_tofree, TRUE, &argv, &argc) == FAIL)
	return FAIL;
    *argvp = argv;

    if (cmd != NULL)
    {
	char_u	*s;
	char_u	*p;

	if (extra_shell_arg != NULL)
	    argv[argc++] = (char *)extra_shell_arg;

	// Break 'shellcmdflag' into white separated parts.  This doesn't
	// handle quoted strings, they are very unlikely to appear.
	*shcf_tofree = alloc(STRLEN(p_shcf) + 1);
	if (*shcf_tofree == NULL)    // out of memory
	    return FAIL;
	s = *shcf_tofree;
	p = p_shcf;
	while (*p != NUL)
	{
	    argv[argc++] = (char *)s;
	    while (*p && *p != ' ' && *p != TAB)
		*s++ = *p++;
	    *s++ = NUL;
	    p = skipwhite(p);
	}

	argv[argc++] = (char *)cmd;
    }
    argv[argc] = NULL;
    return OK;
}
#endif

#if defined(FEAT_GUI) && defined(FEAT_TERMINAL)
/*
 * Use a terminal window to run a shell command in.
 */
    static int
mch_call_shell_terminal(
    char_u	*cmd,
    int		options UNUSED)	// SHELL_*, see vim.h
{
    jobopt_T	opt;
    char	**argv = NULL;
    char_u	*tofree1 = NULL;
    char_u	*tofree2 = NULL;
    int		retval = -1;
    buf_T	*buf;
    job_T	*job;
    aco_save_T	aco;
    oparg_T	oa;		// operator arguments

    if (unix_build_argv(cmd, &argv, &tofree1, &tofree2) == FAIL)
	goto theend;

    init_job_options(&opt);
    ch_log(NULL, "starting terminal for system command '%s'", cmd);
    buf = term_start(NULL, argv, &opt, TERM_START_SYSTEM);
    if (buf == NULL)
	goto theend;

    job = term_getjob(buf->b_term);
    ++job->jv_refcount;

    // Find a window to make "buf" curbuf.
    aucmd_prepbuf(&aco, buf);
    if (curbuf == buf)
    {
	// Only when managed to find a window for "buf",
	clear_oparg(&oa);
	while (term_use_loop())
	{
	    if (oa.op_type == OP_NOP && oa.regname == NUL && !VIsual_active)
	    {
		// If terminal_loop() returns OK we got a key that is handled
		// in Normal model. We don't do redrawing anyway.
		if (terminal_loop(TRUE) == OK)
		    normal_cmd(&oa, TRUE);
	    }
	    else
		normal_cmd(&oa, TRUE);
	}
	retval = job->jv_exitval;
	ch_log(NULL, "system command finished");

	job_unref(job);

	// restore curwin/curbuf and a few other things
	aucmd_restbuf(&aco);
    }

    // Only require pressing Enter when redrawing, to avoid that system() gets
    // the hit-enter prompt even though it didn't output anything.
    if (RedrawingDisabled == 0)
	wait_return(TRUE);
    do_buffer(DOBUF_WIPE, DOBUF_FIRST, FORWARD, buf->b_fnum, TRUE);

theend:
    vim_free(argv);
    vim_free(tofree1);
    vim_free(tofree2);
    return retval;
}
#endif

#ifdef USE_SYSTEM
/*
 * Use system() to start the shell: simple but slow.
 */
    static int
mch_call_shell_system(
    char_u	*cmd,
    int		options)	// SHELL_*, see vim.h
{
#ifdef VMS
    char	*ifn = NULL;
    char	*ofn = NULL;
#endif
    tmode_T	tmode = cur_tmode;
    char_u	*newcmd;	// only needed for unix
    int		x;

    out_flush();

    if (options & SHELL_COOKED)
	settmode(TMODE_COOK);	    // set to normal mode

# if defined(FEAT_CLIPBOARD) && defined(FEAT_X11)
    save_clipboard();
    loose_clipboard();
# endif

    if (cmd == NULL)
	x = system((char *)p_sh);
    else
    {
# ifdef VMS
	if (ofn = strchr((char *)cmd, '>'))
	    *ofn++ = '\0';
	if (ifn = strchr((char *)cmd, '<'))
	{
	    char *p;

	    *ifn++ = '\0';
	    p = strchr(ifn,' '); // chop off any trailing spaces
	    if (p)
		*p = '\0';
	}
	if (ofn)
	    x = vms_sys((char *)cmd, ofn, ifn);
	else
	    x = system((char *)cmd);
# else
	newcmd = alloc(STRLEN(p_sh)
		+ (extra_shell_arg == NULL ? 0 : STRLEN(extra_shell_arg))
		+ STRLEN(p_shcf) + STRLEN(cmd) + 4);
	if (newcmd == NULL)
	    x = 0;
	else
	{
	    sprintf((char *)newcmd, "%s %s %s %s", p_sh,
		    extra_shell_arg == NULL ? "" : (char *)extra_shell_arg,
		    (char *)p_shcf,
		    (char *)cmd);
	    x = system((char *)newcmd);
	    vim_free(newcmd);
	}
# endif
    }
# ifdef VMS
    x = vms_sys_status(x);
# endif
    if (emsg_silent)
	;
    else if (x == 127)
	msg_puts(_("\nCannot execute shell sh\n"));
    else if (x && !(options & SHELL_SILENT))
    {
	msg_puts(_("\nshell returned "));
	msg_outnum((long)x);
	msg_putchar('\n');
    }

    if (tmode == TMODE_RAW)
    {
	// The shell may have messed with the mode, always set it.
	cur_tmode = TMODE_UNKNOWN;
	settmode(TMODE_RAW);	// set to raw mode
    }
    resettitle();
# if defined(FEAT_CLIPBOARD) && defined(FEAT_X11)
    restore_clipboard();
# endif
    return x;
}

#else // USE_SYSTEM

# define EXEC_FAILED 122    // Exit code when shell didn't execute.  Don't use
			    // 127, some shells use that already
# define OPEN_NULL_FAILED 123 // Exit code if /dev/null can't be opened

/*
 * Don't use system(), use fork()/exec().
 */
    static int
mch_call_shell_fork(
    char_u	*cmd,
    int		options)	// SHELL_*, see vim.h
{
    tmode_T	tmode = cur_tmode;
    pid_t	pid;
    pid_t	wpid = 0;
    pid_t	wait_pid = 0;
# ifdef HAVE_UNION_WAIT
    union wait	status;
# else
    int		status = -1;
# endif
    int		retval = -1;
    char	**argv = NULL;
    char_u	*tofree1 = NULL;
    char_u	*tofree2 = NULL;
    int		i;
    int		pty_master_fd = -1;	    // for pty's
# ifdef FEAT_GUI
    int		pty_slave_fd = -1;
# endif
    int		fd_toshell[2];		// for pipes
    int		fd_fromshell[2];
    int		pipe_error = FALSE;
    int		did_settmode = FALSE;	// settmode(TMODE_RAW) called

    out_flush();
    if (options & SHELL_COOKED)
	settmode(TMODE_COOK);		// set to normal mode
    if (tmode == TMODE_RAW)
	// The shell may have messed with the mode, always set it later.
	cur_tmode = TMODE_UNKNOWN;

    if (unix_build_argv(cmd, &argv, &tofree1, &tofree2) == FAIL)
	goto error;

    /*
     * For the GUI, when writing the output into the buffer and when reading
     * input from the buffer: Try using a pseudo-tty to get the stdin/stdout
     * of the executed command into the Vim window.  Or use a pipe.
     */
    if ((options & (SHELL_READ|SHELL_WRITE))
# ifdef FEAT_GUI
	    || (gui.in_use && show_shell_mess)
# endif
		    )
    {
# ifdef FEAT_GUI
	/*
	 * Try to open a master pty.
	 * If this works, open the slave pty.
	 * If the slave can't be opened, close the master pty.
	 */
	if (p_guipty && !(options & (SHELL_READ|SHELL_WRITE)))
	    open_pty(&pty_master_fd, &pty_slave_fd, NULL, NULL);
	/*
	 * If not opening a pty or it didn't work, try using pipes.
	 */
	if (pty_master_fd < 0)
# endif
	{
	    pipe_error = (pipe(fd_toshell) < 0);
	    if (!pipe_error)			    // pipe create OK
	    {
		pipe_error = (pipe(fd_fromshell) < 0);
		if (pipe_error)			    // pipe create failed
		{
		    close(fd_toshell[0]);
		    close(fd_toshell[1]);
		}
	    }
	    if (pipe_error)
	    {
		msg_puts(_("\nCannot create pipes\n"));
		out_flush();
	    }
	}
    }

    if (!pipe_error)			// pty or pipe opened or not used
    {
	SIGSET_DECL(curset)
	BLOCK_SIGNALS(&curset);
	pid = fork();	// maybe we should use vfork()
	if (pid == -1)
	{
	    UNBLOCK_SIGNALS(&curset);

	    msg_puts(_("\nCannot fork\n"));
	    if ((options & (SHELL_READ|SHELL_WRITE))
# ifdef FEAT_GUI
		|| (gui.in_use && show_shell_mess)
# endif
		    )
	    {
# ifdef FEAT_GUI
		if (pty_master_fd >= 0)		// close the pseudo tty
		{
		    close(pty_master_fd);
		    close(pty_slave_fd);
		}
		else				// close the pipes
# endif
		{
		    close(fd_toshell[0]);
		    close(fd_toshell[1]);
		    close(fd_fromshell[0]);
		    close(fd_fromshell[1]);
		}
	    }
	}
	else if (pid == 0)	// child
	{
	    reset_signals();		// handle signals normally
	    UNBLOCK_SIGNALS(&curset);

# ifdef FEAT_EVAL
	    if (ch_log_active())
	    {
		ch_log(NULL, "closing channel log in the child process");
		ch_logfile((char_u *)"", (char_u *)"");
	    }
# endif

	    if (!show_shell_mess || (options & SHELL_EXPAND))
	    {
		int fd;

		/*
		 * Don't want to show any message from the shell.  Can't just
		 * close stdout and stderr though, because some systems will
		 * break if you try to write to them after that, so we must
		 * use dup() to replace them with something else -- webb
		 * Connect stdin to /dev/null too, so ":n `cat`" doesn't hang,
		 * waiting for input.
		 */
		fd = open("/dev/null", O_RDWR | O_EXTRA, 0);
		fclose(stdin);
		fclose(stdout);
		fclose(stderr);

		/*
		 * If any of these open()'s and dup()'s fail, we just continue
		 * anyway.  It's not fatal, and on most systems it will make
		 * no difference at all.  On a few it will cause the execvp()
		 * to exit with a non-zero status even when the completion
		 * could be done, which is nothing too serious.  If the open()
		 * or dup() failed we'd just do the same thing ourselves
		 * anyway -- webb
		 */
		if (fd >= 0)
		{
		    vim_ignored = dup(fd); // To replace stdin  (fd 0)
		    vim_ignored = dup(fd); // To replace stdout (fd 1)
		    vim_ignored = dup(fd); // To replace stderr (fd 2)

		    // Don't need this now that we've duplicated it
		    close(fd);
		}
	    }
	    else if ((options & (SHELL_READ|SHELL_WRITE))
# ifdef FEAT_GUI
		    || gui.in_use
# endif
		    )
	    {

# ifdef HAVE_SETSID
		// Create our own process group, so that the child and all its
		// children can be kill()ed.  Don't do this when using pipes,
		// because stdin is not a tty, we would lose /dev/tty.
		if (p_stmp)
		{
		    (void)setsid();
#  if defined(SIGHUP)
		    // When doing "!xterm&" and 'shell' is bash: the shell
		    // will exit and send SIGHUP to all processes in its
		    // group, killing the just started process.  Ignore SIGHUP
		    // to avoid that. (suggested by Simon Schubert)
		    mch_signal(SIGHUP, SIG_IGN);
#  endif
		}
# endif
# ifdef FEAT_GUI
		if (pty_slave_fd >= 0)
		{
		    // push stream discipline modules
		    if (options & SHELL_COOKED)
			setup_slavepty(pty_slave_fd);
#  ifdef TIOCSCTTY
		    // Try to become controlling tty (probably doesn't work,
		    // unless run by root)
		    ioctl(pty_slave_fd, TIOCSCTTY, (char *)NULL);
#  endif
		}
# endif
		set_default_child_environment(FALSE);

		/*
		 * stderr is only redirected when using the GUI, so that a
		 * program like gpg can still access the terminal to get a
		 * passphrase using stderr.
		 */
# ifdef FEAT_GUI
		if (pty_master_fd >= 0)
		{
		    close(pty_master_fd);   // close master side of pty

		    // set up stdin/stdout/stderr for the child
		    close(0);
		    vim_ignored = dup(pty_slave_fd);
		    close(1);
		    vim_ignored = dup(pty_slave_fd);
		    if (gui.in_use)
		    {
			close(2);
			vim_ignored = dup(pty_slave_fd);
		    }

		    close(pty_slave_fd);    // has been dupped, close it now
		}
		else
# endif
		{
		    // set up stdin for the child
		    close(fd_toshell[1]);
		    close(0);
		    vim_ignored = dup(fd_toshell[0]);
		    close(fd_toshell[0]);

		    // set up stdout for the child
		    close(fd_fromshell[0]);
		    close(1);
		    vim_ignored = dup(fd_fromshell[1]);
		    close(fd_fromshell[1]);

# ifdef FEAT_GUI
		    if (gui.in_use)
		    {
			// set up stderr for the child
			close(2);
			vim_ignored = dup(1);
		    }
# endif
		}
	    }

	    /*
	     * There is no type cast for the argv, because the type may be
	     * different on different machines. This may cause a warning
	     * message with strict compilers, don't worry about it.
	     * Call _exit() instead of exit() to avoid closing the connection
	     * to the X server (esp. with GTK, which uses atexit()).
	     */
	    execvp(argv[0], argv);
	    _exit(EXEC_FAILED);	    // exec failed, return failure code
	}
	else			// parent
	{
	    /*
	     * While child is running, ignore terminating signals.
	     * Do catch CTRL-C, so that "got_int" is set.
	     */
	    catch_signals(SIG_IGN, SIG_ERR);
	    catch_int_signal();
	    UNBLOCK_SIGNALS(&curset);
# ifdef FEAT_JOB_CHANNEL
	    ++dont_check_job_ended;
# endif
	    /*
	     * For the GUI we redirect stdin, stdout and stderr to our window.
	     * This is also used to pipe stdin/stdout to/from the external
	     * command.
	     */
	    if ((options & (SHELL_READ|SHELL_WRITE))
# ifdef FEAT_GUI
		    || (gui.in_use && show_shell_mess)
# endif
	       )
	    {
# define BUFLEN 100		// length for buffer, pseudo tty limit is 128
		char_u	    buffer[BUFLEN + 1];
		int	    buffer_off = 0;	// valid bytes in buffer[]
		char_u	    ta_buf[BUFLEN + 1];	// TypeAHead
		int	    ta_len = 0;		// valid bytes in ta_buf[]
		int	    len;
		int	    p_more_save;
		int	    old_State;
		int	    c;
		int	    toshell_fd;
		int	    fromshell_fd;
		garray_T    ga;
		int	    noread_cnt;
# ifdef ELAPSED_FUNC
		elapsed_T   start_tv;
# endif

# ifdef FEAT_GUI
		if (pty_master_fd >= 0)
		{
		    fromshell_fd = pty_master_fd;
		    toshell_fd = dup(pty_master_fd);
		}
		else
# endif
		{
		    close(fd_toshell[0]);
		    close(fd_fromshell[1]);
		    toshell_fd = fd_toshell[1];
		    fromshell_fd = fd_fromshell[0];
		}

		/*
		 * Write to the child if there are typed characters.
		 * Read from the child if there are characters available.
		 *   Repeat the reading a few times if more characters are
		 *   available. Need to check for typed keys now and then, but
		 *   not too often (delays when no chars are available).
		 * This loop is quit if no characters can be read from the pty
		 * (WaitForChar detected special condition), or there are no
		 * characters available and the child has exited.
		 * Only check if the child has exited when there is no more
		 * output. The child may exit before all the output has
		 * been printed.
		 *
		 * Currently this busy loops!
		 * This can probably dead-lock when the write blocks!
		 */
		p_more_save = p_more;
		p_more = FALSE;
		old_State = State;
		State = MODE_EXTERNCMD;	// don't redraw at window resize

		if ((options & SHELL_WRITE) && toshell_fd >= 0)
		{
		    // Fork a process that will write the lines to the
		    // external program.
		    if ((wpid = fork()) == -1)
		    {
			msg_puts(_("\nCannot fork\n"));
		    }
		    else if (wpid == 0) // child
		    {
			linenr_T    lnum = curbuf->b_op_start.lnum;
			int	    written = 0;
			char_u	    *lp = ml_get(lnum);
			size_t	    l;

			close(fromshell_fd);
			for (;;)
			{
			    l = STRLEN(lp + written);
			    if (l == 0)
				len = 0;
			    else if (lp[written] == NL)
				// NL -> NUL translation
				len = write(toshell_fd, "", (size_t)1);
			    else
			    {
				char_u	*s = vim_strchr(lp + written, NL);

				len = write(toshell_fd, (char *)lp + written,
					   s == NULL ? l
					      : (size_t)(s - (lp + written)));
			    }
			    if (len == (int)l)
			    {
				// Finished a line, add a NL, unless this line
				// should not have one.
				if (lnum != curbuf->b_op_end.lnum
					|| (!curbuf->b_p_bin
					    && curbuf->b_p_fixeol)
					|| (lnum != curbuf->b_no_eol_lnum
					    && (lnum != curbuf->b_ml.ml_line_count
						    || curbuf->b_p_eol)))
				    vim_ignored = write(toshell_fd, "\n",
								   (size_t)1);
				++lnum;
				if (lnum > curbuf->b_op_end.lnum)
				{
				    // finished all the lines, close pipe
				    close(toshell_fd);
				    break;
				}
				lp = ml_get(lnum);
				written = 0;
			    }
			    else if (len > 0)
				written += len;
			}
			_exit(0);
		    }
		    else // parent
		    {
			close(toshell_fd);
			toshell_fd = -1;
		    }
		}

		if (options & SHELL_READ)
		    ga_init2(&ga, 1, BUFLEN);

		noread_cnt = 0;
# ifdef ELAPSED_FUNC
		ELAPSED_INIT(start_tv);
# endif
		for (;;)
		{
		    /*
		     * Check if keys have been typed, write them to the child
		     * if there are any.
		     * Don't do this if we are expanding wild cards (would eat
		     * typeahead).
		     * Don't do this when filtering and terminal is in cooked
		     * mode, the shell command will handle the I/O.  Avoids
		     * that a typed password is echoed for ssh or gpg command.
		     * Don't get characters when the child has already
		     * finished (wait_pid == 0).
		     * Don't read characters unless we didn't get output for a
		     * while (noread_cnt > 4), avoids that ":r !ls" eats
		     * typeahead.
		     */
		    len = 0;
		    if (!(options & SHELL_EXPAND)
			    && ((options &
					 (SHELL_READ|SHELL_WRITE|SHELL_COOKED))
				      != (SHELL_READ|SHELL_WRITE|SHELL_COOKED)
# ifdef FEAT_GUI
						    || gui.in_use
# endif
						    )
			    && wait_pid == 0
			    && (ta_len > 0 || noread_cnt > 4))
		    {
		      if (ta_len == 0)
		      {
			  // Get extra characters when we don't have any.
			  // Reset the counter and timer.
			  noread_cnt = 0;
# ifdef ELAPSED_FUNC
			  ELAPSED_INIT(start_tv);
# endif
			  len = ui_inchar(ta_buf, BUFLEN, 10L, 0);
		      }
		      if (ta_len > 0 || len > 0)
		      {
			/*
			 * For pipes:
			 * Check for CTRL-C: send interrupt signal to child.
			 * Check for CTRL-D: EOF, close pipe to child.
			 */
			if (len == 1 && (pty_master_fd < 0 || cmd != NULL))
			{
			    /*
			     * Send SIGINT to the child's group or all
			     * processes in our group.
			     */
			    may_send_sigint(ta_buf[ta_len], pid, wpid);

			    if (pty_master_fd < 0 && toshell_fd >= 0
					       && ta_buf[ta_len] == Ctrl_D)
			    {
				close(toshell_fd);
				toshell_fd = -1;
			    }
			}

			// Remove Vim-specific codes from the input.
			len = term_replace_keycodes(ta_buf, ta_len, len);

			/*
			 * For pipes: echo the typed characters.
			 * For a pty this does not seem to work.
			 */
			if (pty_master_fd < 0)
			{
			    for (i = ta_len; i < ta_len + len; ++i)
			    {
				if (ta_buf[i] == '\n' || ta_buf[i] == '\b')
				    msg_putchar(ta_buf[i]);
				else if (has_mbyte)
				{
				    int l = (*mb_ptr2len)(ta_buf + i);

				    msg_outtrans_len(ta_buf + i, l);
				    i += l - 1;
				}
				else
				    msg_outtrans_len(ta_buf + i, 1);
			    }
			    windgoto(msg_row, msg_col);
			    out_flush();
			}

			ta_len += len;

			/*
			 * Write the characters to the child, unless EOF has
			 * been typed for pipes.  Write one character at a
			 * time, to avoid losing too much typeahead.
			 * When writing buffer lines, drop the typed
			 * characters (only check for CTRL-C).
			 */
			if (options & SHELL_WRITE)
			    ta_len = 0;
			else if (toshell_fd >= 0)
			{
			    len = write(toshell_fd, (char *)ta_buf, (size_t)1);
			    if (len > 0)
			    {
				ta_len -= len;
				mch_memmove(ta_buf, ta_buf + len, ta_len);
			    }
			}
		      }
		    }

		    if (got_int)
		    {
			// CTRL-C sends a signal to the child, we ignore it
			// ourselves
#  ifdef HAVE_SETSID
			kill(-pid, SIGINT);
#  else
			kill(0, SIGINT);
#  endif
			if (wpid > 0)
			    kill(wpid, SIGINT);
			got_int = FALSE;
		    }

		    /*
		     * Check if the child has any characters to be printed.
		     * Read them and write them to our window.	Repeat this as
		     * long as there is something to do, avoid the 10ms wait
		     * for mch_inchar(), or sending typeahead characters to
		     * the external process.
		     * TODO: This should handle escape sequences, compatible
		     * to some terminal (vt52?).
		     */
		    ++noread_cnt;
		    while (RealWaitForChar(fromshell_fd, 10L, NULL, NULL))
		    {
			len = read_eintr(fromshell_fd, buffer
				+ buffer_off, (size_t)(BUFLEN - buffer_off)
				);
			if (len <= 0)		    // end of file or error
			    goto finished;

			noread_cnt = 0;
			if (options & SHELL_READ)
			{
			    // Do NUL -> NL translation, append NL separated
			    // lines to the current buffer.
			    for (i = 0; i < len; ++i)
			    {
				if (buffer[i] == NL)
				    append_ga_line(&ga);
				else if (buffer[i] == NUL)
				    ga_append(&ga, NL);
				else
				    ga_append(&ga, buffer[i]);
			    }
			}
			else if (has_mbyte)
			{
			    int		l;
			    char_u	*p;

			    len += buffer_off;
			    buffer[len] = NUL;

			    // Check if the last character in buffer[] is
			    // incomplete, keep these bytes for the next
			    // round.
			    for (p = buffer; p < buffer + len; p += l)
			    {
				l = MB_CPTR2LEN(p);
				if (l == 0)
				    l = 1;  // NUL byte?
				else if (MB_BYTE2LEN(*p) != l)
				    break;
			    }
			    if (p == buffer)	// no complete character
			    {
				// avoid getting stuck at an illegal byte
				if (len >= 12)
				    ++p;
				else
				{
				    buffer_off = len;
				    continue;
				}
			    }
			    c = *p;
			    *p = NUL;
			    msg_puts((char *)buffer);
			    if (p < buffer + len)
			    {
				*p = c;
				buffer_off = (buffer + len) - p;
				mch_memmove(buffer, p, buffer_off);
				continue;
			    }
			    buffer_off = 0;
			}
			else
			{
			    buffer[len] = NUL;
			    msg_puts((char *)buffer);
			}

			windgoto(msg_row, msg_col);
			cursor_on();
			out_flush();
			if (got_int)
			    break;

# ifdef ELAPSED_FUNC
			if (wait_pid == 0)
			{
			    long	msec = ELAPSED_FUNC(start_tv);

			    // Avoid that we keep looping here without
			    // checking for a CTRL-C for a long time.  Don't
			    // break out too often to avoid losing typeahead.
			    if (msec > 2000)
			    {
				noread_cnt = 5;
				break;
			    }
			}
# endif
		    }

		    // If we already detected the child has finished, continue
		    // reading output for a short while.  Some text may be
		    // buffered.
		    if (wait_pid == pid)
		    {
			if (noread_cnt < 5)
			    continue;
			break;
		    }

		    /*
		     * Check if the child still exists, before checking for
		     * typed characters (otherwise we would lose typeahead).
		     */
# ifdef __NeXT__
		    wait_pid = wait4(pid, &status, WNOHANG, (struct rusage *)0);
# else
		    wait_pid = waitpid(pid, &status, WNOHANG);
# endif
		    if ((wait_pid == (pid_t)-1 && errno == ECHILD)
			    || (wait_pid == pid && WIFEXITED(status)))
		    {
			// Don't break the loop yet, try reading more
			// characters from "fromshell_fd" first.  When using
			// pipes there might still be something to read and
			// then we'll break the loop at the "break" above.
			wait_pid = pid;
		    }
		    else
			wait_pid = 0;

# if defined(FEAT_XCLIPBOARD) && defined(FEAT_X11)
		    // Handle any X events, e.g. serving the clipboard.
		    clip_update();
# endif
		}
finished:
		p_more = p_more_save;
		if (options & SHELL_READ)
		{
		    if (ga.ga_len > 0)
		    {
			append_ga_line(&ga);
			// remember that the NL was missing
			curbuf->b_no_eol_lnum = curwin->w_cursor.lnum;
		    }
		    else
			curbuf->b_no_eol_lnum = 0;
		    ga_clear(&ga);
		}

		/*
		 * Give all typeahead that wasn't used back to ui_inchar().
		 */
		if (ta_len)
		    ui_inchar_undo(ta_buf, ta_len);
		State = old_State;
		if (toshell_fd >= 0)
		    close(toshell_fd);
		close(fromshell_fd);
	    }
# if defined(FEAT_XCLIPBOARD) && defined(FEAT_X11)
	    else
	    {
		long delay_msec = 1;

		if (tmode == TMODE_RAW)
		    // Possibly disables modifyOtherKeys, so that the system
		    // can recognize CTRL-C.
		    out_str_t_TE();

		/*
		 * Similar to the loop above, but only handle X events, no
		 * I/O.
		 */
		for (;;)
		{
		    if (got_int)
		    {
			// CTRL-C sends a signal to the child, we ignore it
			// ourselves
#  ifdef HAVE_SETSID
			kill(-pid, SIGINT);
#  else
			kill(0, SIGINT);
#  endif
			got_int = FALSE;
		    }
# ifdef __NeXT__
		    wait_pid = wait4(pid, &status, WNOHANG, (struct rusage *)0);
# else
		    wait_pid = waitpid(pid, &status, WNOHANG);
# endif
		    if ((wait_pid == (pid_t)-1 && errno == ECHILD)
			    || (wait_pid == pid && WIFEXITED(status)))
		    {
			wait_pid = pid;
			break;
		    }

		    // Handle any X events, e.g. serving the clipboard.
		    clip_update();

		    // Wait for 1 to 10 msec. 1 is faster but gives the child
		    // less time, gradually wait longer.
		    mch_delay(delay_msec,
				   MCH_DELAY_IGNOREINPUT | MCH_DELAY_SETTMODE);
		    if (++delay_msec > 10)
			delay_msec = 10;
		}

		if (tmode == TMODE_RAW)
		    // possibly enables modifyOtherKeys again
		    out_str_t_TI();
	    }
# endif

	    /*
	     * Wait until our child has exited.
	     * Ignore wait() returning pids of other children and returning
	     * because of some signal like SIGWINCH.
	     * Don't wait if wait_pid was already set above, indicating the
	     * child already exited.
	     */
	    if (wait_pid != pid)
		(void)wait4pid(pid, &status);

# ifdef FEAT_GUI
	    // Close slave side of pty.  Only do this after the child has
	    // exited, otherwise the child may hang when it tries to write on
	    // the pty.
	    if (pty_master_fd >= 0)
		close(pty_slave_fd);
# endif

	    // Make sure the child that writes to the external program is
	    // dead.
	    if (wpid > 0)
	    {
		kill(wpid, SIGKILL);
		wait4pid(wpid, NULL);
	    }

# ifdef FEAT_JOB_CHANNEL
	    --dont_check_job_ended;
# endif

	    /*
	     * Set to raw mode right now, otherwise a CTRL-C after
	     * catch_signals() will kill Vim.
	     */
	    if (tmode == TMODE_RAW)
		settmode(TMODE_RAW);
	    did_settmode = TRUE;
	    set_signals();

	    if (WIFEXITED(status))
	    {
		// LINTED avoid "bitwise operation on signed value"
		retval = WEXITSTATUS(status);
		if (retval != 0 && !emsg_silent)
		{
		    if (retval == EXEC_FAILED)
		    {
			msg_puts(_("\nCannot execute shell "));
			msg_outtrans(p_sh);
			msg_putchar('\n');
		    }
		    else if (!(options & SHELL_SILENT))
		    {
			msg_puts(_("\nshell returned "));
			msg_outnum((long)retval);
			msg_putchar('\n');
		    }
		}
	    }
	    else
		msg_puts(_("\nCommand terminated\n"));
	}
    }

error:
    if (!did_settmode)
	if (tmode == TMODE_RAW)
	    settmode(TMODE_RAW);	// set to raw mode
    resettitle();
    vim_free(argv);
    vim_free(tofree1);
    vim_free(tofree2);

    return retval;
}
#endif // USE_SYSTEM

    int
mch_call_shell(
    char_u	*cmd,
    int		options)	// SHELL_*, see vim.h
{
#ifdef FEAT_EVAL
    ch_log(NULL, "executing shell command: %s", cmd);
#endif
#if defined(FEAT_GUI) && defined(FEAT_TERMINAL)
    if (gui.in_use && vim_strchr(p_go, GO_TERMINAL) != NULL
					      && (options & SHELL_SILENT) == 0)
	return mch_call_shell_terminal(cmd, options);
#endif
#ifdef USE_SYSTEM
    return mch_call_shell_system(cmd, options);
#else
    return mch_call_shell_fork(cmd, options);
#endif
}

#if defined(FEAT_JOB_CHANNEL) || defined(PROTO)
    void
mch_job_start(char **argv, job_T *job, jobopt_T *options, int is_terminal)
{
    pid_t	pid;
    int		fd_in[2] = {-1, -1};	// for stdin
    int		fd_out[2] = {-1, -1};	// for stdout
    int		fd_err[2] = {-1, -1};	// for stderr
    int		pty_master_fd = -1;
    int		pty_slave_fd = -1;
    channel_T	*channel = NULL;
    int		use_null_for_in = options->jo_io[PART_IN] == JIO_NULL;
    int		use_null_for_out = options->jo_io[PART_OUT] == JIO_NULL;
    int		use_null_for_err = options->jo_io[PART_ERR] == JIO_NULL;
    int		use_file_for_in = options->jo_io[PART_IN] == JIO_FILE;
    int		use_file_for_out = options->jo_io[PART_OUT] == JIO_FILE;
    int		use_file_for_err = options->jo_io[PART_ERR] == JIO_FILE;
    int		use_buffer_for_in = options->jo_io[PART_IN] == JIO_BUFFER;
    int		use_out_for_err = options->jo_io[PART_ERR] == JIO_OUT;
    SIGSET_DECL(curset)

    if (use_out_for_err && use_null_for_out)
	use_null_for_err = TRUE;

    // default is to fail
    job->jv_status = JOB_FAILED;

    if (options->jo_pty
	    && (!(use_file_for_in || use_null_for_in)
		|| !(use_file_for_out || use_null_for_out)
		|| !(use_out_for_err || use_file_for_err || use_null_for_err)))
	open_pty(&pty_master_fd, &pty_slave_fd,
					    &job->jv_tty_out, &job->jv_tty_in);

    // TODO: without the channel feature connect the child to /dev/null?
    // Open pipes for stdin, stdout, stderr.
    if (use_file_for_in)
    {
	char_u *fname = options->jo_io_name[PART_IN];

	fd_in[0] = mch_open((char *)fname, O_RDONLY, 0);
	if (fd_in[0] < 0)
	{
	    semsg(_(e_cant_open_file_str), fname);
	    goto failed;
	}
    }
    else
	// When writing buffer lines to the input don't use the pty, so that
	// the pipe can be closed when all lines were written.
	if (!use_null_for_in && (pty_master_fd < 0 || use_buffer_for_in)
							    && pipe(fd_in) < 0)
	    goto failed;

    if (use_file_for_out)
    {
	char_u *fname = options->jo_io_name[PART_OUT];

	fd_out[1] = mch_open((char *)fname, O_WRONLY | O_CREAT | O_TRUNC, 0644);
	if (fd_out[1] < 0)
	{
	    semsg(_(e_cant_open_file_str), fname);
	    goto failed;
	}
    }
    else if (!use_null_for_out && pty_master_fd < 0 && pipe(fd_out) < 0)
	goto failed;

    if (use_file_for_err)
    {
	char_u *fname = options->jo_io_name[PART_ERR];

	fd_err[1] = mch_open((char *)fname, O_WRONLY | O_CREAT | O_TRUNC, 0600);
	if (fd_err[1] < 0)
	{
	    semsg(_(e_cant_open_file_str), fname);
	    goto failed;
	}
    }
    else if (!use_out_for_err && !use_null_for_err
				      && pty_master_fd < 0 && pipe(fd_err) < 0)
	goto failed;

    if (!use_null_for_in || !use_null_for_out || !use_null_for_err)
    {
	if (options->jo_set & JO_CHANNEL)
	{
	    channel = options->jo_channel;
	    if (channel != NULL)
		++channel->ch_refcount;
	}
	else
	    channel = add_channel();
	if (channel == NULL)
	    goto failed;
	if (job->jv_tty_out != NULL)
	    ch_log(channel, "using pty %s on fd %d",
					       job->jv_tty_out, pty_master_fd);
    }

    BLOCK_SIGNALS(&curset);
    pid = fork();	// maybe we should use vfork()
    if (pid == -1)
    {
	// failed to fork
	UNBLOCK_SIGNALS(&curset);
	goto failed;
    }
    if (pid == 0)
    {
	int	null_fd = -1;
	int	stderr_works = TRUE;

	// child
	reset_signals();		// handle signals normally
	UNBLOCK_SIGNALS(&curset);

# ifdef FEAT_EVAL
	if (ch_log_active())
	    // close the log file in the child
	    ch_logfile((char_u *)"", (char_u *)"");
# endif

# ifdef HAVE_SETSID
	// Create our own process group, so that the child and all its
	// children can be kill()ed.  Don't do this when using pipes,
	// because stdin is not a tty, we would lose /dev/tty.
	(void)setsid();
# endif

# ifdef FEAT_TERMINAL
	if (options->jo_term_rows > 0)
	{
	    char *term = (char *)T_NAME;

#ifdef FEAT_GUI
	    if (term_is_gui(T_NAME))
		// In the GUI 'term' is not what we want, use $TERM.
		term = getenv("TERM");
#endif
	    // Use 'term' or $TERM if it starts with "xterm", otherwise fall
	    // back to "xterm" or "xterm-color".
	    if (term == NULL || *term == NUL || STRNCMP(term, "xterm", 5) != 0)
	    {
		if (t_colors >= 256)
		    // TODO: should we check this name is supported?
		    term = "xterm-256color";
		else if (t_colors > 16)
		    term = "xterm-color";
		else
		    term = "xterm";
	    }
	    set_child_environment(
		    (long)options->jo_term_rows,
		    (long)options->jo_term_cols,
		    term,
		    is_terminal);
	}
	else
# endif
	    set_default_child_environment(is_terminal);

	if (options->jo_env != NULL)
	{
	    dict_T	*dict = options->jo_env;
	    hashitem_T	*hi;
	    int		todo = (int)dict->dv_hashtab.ht_used;

	    FOR_ALL_HASHTAB_ITEMS(&dict->dv_hashtab, hi, todo)
		if (!HASHITEM_EMPTY(hi))
		{
		    typval_T *item = &dict_lookup(hi)->di_tv;

		    vim_setenv(hi->hi_key, tv_get_string(item));
		    --todo;
		}
	}

	if (use_null_for_in || use_null_for_out || use_null_for_err)
	{
	    null_fd = open("/dev/null", O_RDWR | O_EXTRA, 0);
	    if (null_fd < 0)
	    {
		perror("opening /dev/null failed");
		_exit(OPEN_NULL_FAILED);
	    }
	}

	if (pty_slave_fd >= 0)
	{
	    // push stream discipline modules
	    setup_slavepty(pty_slave_fd);
#  ifdef TIOCSCTTY
	    // Try to become controlling tty (probably doesn't work,
	    // unless run by root)
	    ioctl(pty_slave_fd, TIOCSCTTY, (char *)NULL);
#  endif
	}

	// set up stdin for the child
	close(0);
	if (use_null_for_in && null_fd >= 0)
	    vim_ignored = dup(null_fd);
	else if (fd_in[0] < 0)
	    vim_ignored = dup(pty_slave_fd);
	else
	    vim_ignored = dup(fd_in[0]);

	// set up stderr for the child
	close(2);
	if (use_null_for_err && null_fd >= 0)
	{
	    vim_ignored = dup(null_fd);
	    stderr_works = FALSE;
	}
	else if (use_out_for_err)
	    vim_ignored = dup(fd_out[1]);
	else if (fd_err[1] < 0)
	    vim_ignored = dup(pty_slave_fd);
	else
	    vim_ignored = dup(fd_err[1]);

	// set up stdout for the child
	close(1);
	if (use_null_for_out && null_fd >= 0)
	    vim_ignored = dup(null_fd);
	else if (fd_out[1] < 0)
	    vim_ignored = dup(pty_slave_fd);
	else
	    vim_ignored = dup(fd_out[1]);

	if (fd_in[0] >= 0)
	    close(fd_in[0]);
	if (fd_in[1] >= 0)
	    close(fd_in[1]);
	if (fd_out[0] >= 0)
	    close(fd_out[0]);
	if (fd_out[1] >= 0)
	    close(fd_out[1]);
	if (fd_err[0] >= 0)
	    close(fd_err[0]);
	if (fd_err[1] >= 0)
	    close(fd_err[1]);
	if (pty_master_fd >= 0)
	{
	    close(pty_master_fd); // not used in the child
	    close(pty_slave_fd);  // was duped above
	}

	if (null_fd >= 0)
	    close(null_fd);

	if (options->jo_cwd != NULL && mch_chdir((char *)options->jo_cwd) != 0)
	    _exit(EXEC_FAILED);

	// See above for type of argv.
	execvp(argv[0], argv);

	if (stderr_works)
	    perror("executing job failed");
# ifdef EXITFREE
	// calling free_all_mem() here causes problems. Ignore valgrind
	// reporting possibly leaked memory.
# endif
	_exit(EXEC_FAILED);	    // exec failed, return failure code
    }

    // parent
    UNBLOCK_SIGNALS(&curset);

    job->jv_pid = pid;
    job->jv_status = JOB_STARTED;
    job->jv_channel = channel;  // ch_refcount was set above

    if (pty_master_fd >= 0)
	close(pty_slave_fd); // not used in the parent
    // close child stdin, stdout and stderr
    if (fd_in[0] >= 0)
	close(fd_in[0]);
    if (fd_out[1] >= 0)
	close(fd_out[1]);
    if (fd_err[1] >= 0)
	close(fd_err[1]);
    if (channel != NULL)
    {
	int in_fd = INVALID_FD;
	int out_fd = INVALID_FD;
	int err_fd = INVALID_FD;

	if (!(use_file_for_in || use_null_for_in))
	    in_fd = fd_in[1] >= 0 ? fd_in[1] : pty_master_fd;

	if (!(use_file_for_out || use_null_for_out))
	    out_fd = fd_out[0] >= 0 ? fd_out[0] : pty_master_fd;

	// When using pty_master_fd only set it for stdout, do not duplicate
	// it for stderr, it only needs to be read once.
	if (!(use_out_for_err || use_file_for_err || use_null_for_err))
	{
	    if (fd_err[0] >= 0)
		err_fd = fd_err[0];
	    else if (out_fd != pty_master_fd)
		err_fd = pty_master_fd;
	}

	channel_set_pipes(channel, in_fd, out_fd, err_fd);
	channel_set_job(channel, job, options);
    }
    else
    {
	if (fd_in[1] >= 0)
	    close(fd_in[1]);
	if (fd_out[0] >= 0)
	    close(fd_out[0]);
	if (fd_err[0] >= 0)
	    close(fd_err[0]);
	if (pty_master_fd >= 0)
	    close(pty_master_fd);
    }

    // success!
    return;

failed:
    channel_unref(channel);
    if (fd_in[0] >= 0)
	close(fd_in[0]);
    if (fd_in[1] >= 0)
	close(fd_in[1]);
    if (fd_out[0] >= 0)
	close(fd_out[0]);
    if (fd_out[1] >= 0)
	close(fd_out[1]);
    if (fd_err[0] >= 0)
	close(fd_err[0]);
    if (fd_err[1] >= 0)
	close(fd_err[1]);
    if (pty_master_fd >= 0)
	close(pty_master_fd);
    if (pty_slave_fd >= 0)
	close(pty_slave_fd);
}

    static char_u *
get_signal_name(int sig)
{
    int		i;
    char_u	numbuf[NUMBUFLEN];

    if (sig == SIGKILL)
	return vim_strsave((char_u *)"kill");

    for (i = 0; signal_info[i].sig != -1; i++)
	if (sig == signal_info[i].sig)
	    return strlow_save((char_u *)signal_info[i].name);

    vim_snprintf((char *)numbuf, NUMBUFLEN, "%d", sig);
    return vim_strsave(numbuf);
}

    char *
mch_job_status(job_T *job)
{
# ifdef HAVE_UNION_WAIT
    union wait	status;
# else
    int		status = -1;
# endif
    pid_t	wait_pid = 0;

# ifdef __NeXT__
    wait_pid = wait4(job->jv_pid, &status, WNOHANG, (struct rusage *)0);
# else
    wait_pid = waitpid(job->jv_pid, &status, WNOHANG);
# endif
    if (wait_pid == -1)
    {
	int waitpid_errno = errno;
	if (waitpid_errno == ECHILD && mch_process_running(job->jv_pid))
	    // The process is alive, but it was probably reparented (for
	    // example by ptrace called by a debugger like lldb or gdb).
	    // Note: This assumes that process IDs are not reused.
	    return "run";

	// process must have exited
	if (job->jv_status < JOB_ENDED)
	    ch_log(job->jv_channel, "Job no longer exists: %s",
						      strerror(waitpid_errno));
	goto return_dead;
    }
    if (wait_pid == 0)
	return "run";
    if (WIFEXITED(status))
    {
	// LINTED avoid "bitwise operation on signed value"
	job->jv_exitval = WEXITSTATUS(status);
	if (job->jv_status < JOB_ENDED)
	    ch_log(job->jv_channel, "Job exited with %d", job->jv_exitval);
	goto return_dead;
    }
    if (WIFSIGNALED(status))
    {
	job->jv_exitval = -1;
	job->jv_termsig = get_signal_name(WTERMSIG(status));
	if (job->jv_status < JOB_ENDED && job->jv_termsig != NULL)
	    ch_log(job->jv_channel, "Job terminated by signal \"%s\"",
							      job->jv_termsig);
	goto return_dead;
    }
    return "run";

return_dead:
    if (job->jv_status < JOB_ENDED)
	job->jv_status = JOB_ENDED;
    return "dead";
}

    job_T *
mch_detect_ended_job(job_T *job_list)
{
# ifdef HAVE_UNION_WAIT
    union wait	status;
# else
    int		status = -1;
# endif
    pid_t	wait_pid = 0;
    job_T	*job;

# ifndef USE_SYSTEM
    // Do not do this when waiting for a shell command to finish, we would get
    // the exit value here (and discard it), the exit value obtained there
    // would then be wrong.
    if (dont_check_job_ended > 0)
	return NULL;
# endif

# ifdef __NeXT__
    wait_pid = wait4(-1, &status, WNOHANG, (struct rusage *)0);
# else
    wait_pid = waitpid(-1, &status, WNOHANG);
# endif
    if (wait_pid <= 0)
	// no process ended
	return NULL;
    for (job = job_list; job != NULL; job = job->jv_next)
    {
	if (job->jv_pid == wait_pid)
	{
	    if (WIFEXITED(status))
		// LINTED avoid "bitwise operation on signed value"
		job->jv_exitval = WEXITSTATUS(status);
	    else if (WIFSIGNALED(status))
	    {
		job->jv_exitval = -1;
		job->jv_termsig = get_signal_name(WTERMSIG(status));
	    }
	    if (job->jv_status < JOB_ENDED)
	    {
		ch_log(job->jv_channel, "Job ended");
		job->jv_status = JOB_ENDED;
	    }
	    return job;
	}
    }
    return NULL;
}

/*
 * Send a (deadly) signal to "job".
 * Return FAIL if "how" is not a valid name.
 */
    int
mch_signal_job(job_T *job, char_u *how)
{
    int	    sig = -1;

    if (*how == NUL || STRCMP(how, "term") == 0)
	sig = SIGTERM;
    else if (STRCMP(how, "hup") == 0)
	sig = SIGHUP;
    else if (STRCMP(how, "quit") == 0)
	sig = SIGQUIT;
    else if (STRCMP(how, "int") == 0)
	sig = SIGINT;
    else if (STRCMP(how, "kill") == 0)
	sig = SIGKILL;
#ifdef SIGWINCH
    else if (STRCMP(how, "winch") == 0)
	sig = SIGWINCH;
#endif
    else if (SAFE_isdigit(*how))
	sig = atoi((char *)how);
    else
	return FAIL;

    // Never kill ourselves!
    if (job->jv_pid != 0)
    {
	// TODO: have an option to only kill the process, not the group?
	kill(-job->jv_pid, sig);
	kill(job->jv_pid, sig);
    }

    return OK;
}

/*
 * Clear the data related to "job".
 */
    void
mch_clear_job(job_T *job)
{
    // call waitpid because child process may become zombie
# ifdef __NeXT__
    (void)wait4(job->jv_pid, NULL, WNOHANG, (struct rusage *)0);
# else
    (void)waitpid(job->jv_pid, NULL, WNOHANG);
# endif
}
#endif

#if defined(FEAT_TERMINAL) || defined(PROTO)
    int
mch_create_pty_channel(job_T *job, jobopt_T *options)
{
    int		pty_master_fd = -1;
    int		pty_slave_fd = -1;
    channel_T	*channel;

    open_pty(&pty_master_fd, &pty_slave_fd, &job->jv_tty_out, &job->jv_tty_in);
    if (pty_master_fd < 0 || pty_slave_fd < 0)
	return FAIL;
    close(pty_slave_fd);

    channel = add_channel();
    if (channel == NULL)
    {
	close(pty_master_fd);
	return FAIL;
    }
    if (job->jv_tty_out != NULL)
	ch_log(channel, "using pty %s on fd %d",
					       job->jv_tty_out, pty_master_fd);
    job->jv_channel = channel;  // ch_refcount was set by add_channel()
    channel->ch_keep_open = TRUE;

    // Only set the pty_master_fd for stdout, do not duplicate it for stderr,
    // it only needs to be read once.
    channel_set_pipes(channel, pty_master_fd, pty_master_fd, INVALID_FD);
    channel_set_job(channel, job, options);
    return OK;
}
#endif

/*
 * Check for CTRL-C typed by reading all available characters.
 * In cooked mode we should get SIGINT, no need to check.
 */
    void
mch_breakcheck(int force)
{
    if ((mch_cur_tmode == TMODE_RAW || force)
			       && RealWaitForChar(read_cmd_fd, 0L, NULL, NULL))
	fill_input_buf(FALSE);
}

/*
 * Wait "msec" msec until a character is available from the mouse, keyboard,
 * from inbuf[].
 * "msec" == -1 will block forever.
 * Invokes timer callbacks when needed.
 * When "ignore_input" is TRUE even check for pending input when input is
 * already available.
 * "interrupted" (if not NULL) is set to TRUE when no character is available
 * but something else needs to be done.
 * Returns TRUE when a character is available.
 * When a GUI is being used, this will never get called -- webb
 */
    static int
WaitForChar(long msec, int *interrupted, int ignore_input)
{
#ifdef FEAT_TIMERS
    return ui_wait_for_chars_or_timer(
		    msec, WaitForCharOrMouse, interrupted, ignore_input) == OK;
#else
    return WaitForCharOrMouse(msec, interrupted, ignore_input);
#endif
}

/*
 * Wait "msec" msec until a character is available from the mouse or keyboard
 * or from inbuf[].
 * "msec" == -1 will block forever.
 * for "ignore_input" see WaitForCharOr().
 * "interrupted" (if not NULL) is set to TRUE when no character is available
 * but something else needs to be done.
 * When a GUI is being used, this will never get called -- webb
 */
    static int
WaitForCharOrMouse(long msec, int *interrupted, int ignore_input)
{
#ifdef FEAT_MOUSE_GPM
    int		gpm_process_wanted;
#endif
#ifdef FEAT_XCLIPBOARD
    int		rest;
#endif
    int		avail;

    if (!ignore_input && input_available())	    // something in inbuf[]
	return 1;

#if defined(FEAT_MOUSE_DEC)
    // May need to query the mouse position.
    if (WantQueryMouse)
    {
	WantQueryMouse = FALSE;
	if (!no_query_mouse_for_testing)
	    mch_write((char_u *)"\033[1'|", 5);
    }
#endif

    /*
     * For FEAT_MOUSE_GPM and FEAT_XCLIPBOARD we loop here to process mouse
     * events.  This is a bit complicated, because they might both be defined.
     */
#if defined(FEAT_MOUSE_GPM) || defined(FEAT_XCLIPBOARD)
# ifdef FEAT_XCLIPBOARD
    rest = 0;
    if (do_xterm_trace())
	rest = msec;
# endif
    do
    {
# ifdef FEAT_XCLIPBOARD
	if (rest != 0)
	{
	    msec = XT_TRACE_DELAY;
	    if (rest >= 0 && rest < XT_TRACE_DELAY)
		msec = rest;
	    if (rest >= 0)
		rest -= msec;
	}
# endif
# ifdef FEAT_SOUND_MACOSX
	// Invoke any pending sound callbacks.
	process_cfrunloop();
# endif
# ifdef FEAT_SOUND_CANBERRA
	// Invoke any pending sound callbacks.
	if (has_sound_callback_in_queue())
	    invoke_sound_callback();
# endif
# ifdef FEAT_MOUSE_GPM
	gpm_process_wanted = 0;
	avail = RealWaitForChar(read_cmd_fd, msec,
					     &gpm_process_wanted, interrupted);
	if (!avail && !gpm_process_wanted)
# else
	avail = RealWaitForChar(read_cmd_fd, msec, NULL, interrupted);
	if (!avail)
# endif
	{
	    if (!ignore_input && input_available())
		return 1;
# ifdef FEAT_XCLIPBOARD
	    if (rest == 0 || !do_xterm_trace())
# endif
		break;
	}
    }
    while (FALSE
# ifdef FEAT_MOUSE_GPM
	   || (gpm_process_wanted && mch_gpm_process() == 0)
# endif
# ifdef FEAT_XCLIPBOARD
	   || (!avail && rest != 0)
# endif
	  )
	;

#else
    avail = RealWaitForChar(read_cmd_fd, msec, NULL, interrupted);
#endif
    return avail;
}

#ifndef VMS
/*
 * Wait "msec" msec until a character is available from file descriptor "fd".
 * "msec" == 0 will check for characters once.
 * "msec" == -1 will block until a character is available.
 * When a GUI is being used, this will not be used for input -- webb
 * Or when a Linux GPM mouse event is waiting.
 * Or when a clientserver message is on the queue.
 * "interrupted" (if not NULL) is set to TRUE when no character is available
 * but something else needs to be done.
 */
    static int
RealWaitForChar(int fd, long msec, int *check_for_gpm UNUSED, int *interrupted)
{
    int		ret;
    int		result;
#if defined(FEAT_XCLIPBOARD) || defined(USE_XSMP) || defined(FEAT_MZSCHEME)
    static int	busy = FALSE;

    // May retry getting characters after an event was handled.
# define MAY_LOOP

# ifdef ELAPSED_FUNC
    // Remember at what time we started, so that we know how much longer we
    // should wait after being interrupted.
    long	start_msec = msec;
    elapsed_T	start_tv;

    if (msec > 0)
	ELAPSED_INIT(start_tv);
# endif

    // Handle being called recursively.  This may happen for the session
    // manager stuff, it may save the file, which does a breakcheck.
    if (busy)
	return 0;
#endif

#ifdef MAY_LOOP
    for (;;)
#endif
    {
#ifdef MAY_LOOP
	int		finished = TRUE; // default is to 'loop' just once
# ifdef FEAT_MZSCHEME
	int		mzquantum_used = FALSE;
# endif
#endif
#ifndef HAVE_SELECT
			// each channel may use in, out and err
	struct pollfd   fds[6 + 3 * MAX_OPEN_CHANNELS];
	int		nfd;
# ifdef FEAT_XCLIPBOARD
	int		xterm_idx = -1;
# endif
# ifdef FEAT_MOUSE_GPM
	int		gpm_idx = -1;
# endif
# ifdef USE_XSMP
	int		xsmp_idx = -1;
# endif
	int		towait = (int)msec;

# ifdef FEAT_MZSCHEME
	mzvim_check_threads();
	if (mzthreads_allowed() && p_mzq > 0 && (msec < 0 || msec > p_mzq))
	{
	    towait = (int)p_mzq;    // don't wait longer than 'mzquantum'
	    mzquantum_used = TRUE;
	}
# endif
	fds[0].fd = fd;
	fds[0].events = POLLIN;
	nfd = 1;

# ifdef FEAT_XCLIPBOARD
	may_restore_clipboard();
	if (xterm_Shell != (Widget)0)
	{
	    xterm_idx = nfd;
	    fds[nfd].fd = ConnectionNumber(xterm_dpy);
	    fds[nfd].events = POLLIN;
	    nfd++;
	}
# endif
# ifdef FEAT_MOUSE_GPM
	if (check_for_gpm != NULL && gpm_flag && gpm_fd >= 0)
	{
	    gpm_idx = nfd;
	    fds[nfd].fd = gpm_fd;
	    fds[nfd].events = POLLIN;
	    nfd++;
	}
# endif
# ifdef USE_XSMP
	if (xsmp_icefd != -1)
	{
	    xsmp_idx = nfd;
	    fds[nfd].fd = xsmp_icefd;
	    fds[nfd].events = POLLIN;
	    nfd++;
	}
# endif
#ifdef FEAT_JOB_CHANNEL
	nfd = channel_poll_setup(nfd, &fds, &towait);
#endif
	if (interrupted != NULL)
	    *interrupted = FALSE;

	ret = poll(fds, nfd, towait);

	result = ret > 0 && (fds[0].revents & POLLIN);
	if (result == 0 && interrupted != NULL && ret > 0)
	    *interrupted = TRUE;

# ifdef FEAT_MZSCHEME
	if (ret == 0 && mzquantum_used)
	    // MzThreads scheduling is required and timeout occurred
	    finished = FALSE;
# endif

# ifdef FEAT_XCLIPBOARD
	if (xterm_Shell != (Widget)0 && (fds[xterm_idx].revents & POLLIN))
	{
	    xterm_update();      // Maybe we should hand out clipboard
	    if (--ret == 0 && !input_available())
		// Try again
		finished = FALSE;
	}
# endif
# ifdef FEAT_MOUSE_GPM
	if (gpm_idx >= 0 && (fds[gpm_idx].revents & POLLIN))
	    *check_for_gpm = 1;
# endif
# ifdef USE_XSMP
	if (xsmp_idx >= 0 && (fds[xsmp_idx].revents & (POLLIN | POLLHUP)))
	{
	    if (fds[xsmp_idx].revents & POLLIN)
	    {
		busy = TRUE;
		xsmp_handle_requests();
		busy = FALSE;
	    }
	    else if (fds[xsmp_idx].revents & POLLHUP)
	    {
		if (p_verbose > 0)
		    verb_msg(_("XSMP lost ICE connection"));
		xsmp_close();
	    }
	    if (--ret == 0)
		finished = FALSE;	// Try again
	}
# endif
#ifdef FEAT_JOB_CHANNEL
	// also call when ret == 0, we may be polling a keep-open channel
	if (ret >= 0)
	    channel_poll_check(ret, &fds);
#endif

#else // HAVE_SELECT

	struct timeval  tv;
	struct timeval	*tvp;
	// These are static because they can take 8 Kbyte each and cause the
	// signal stack to run out with -O3.
	static fd_set	rfds, wfds, efds;
	int		maxfd;
	long		towait = msec;

# ifdef FEAT_MZSCHEME
	mzvim_check_threads();
	if (mzthreads_allowed() && p_mzq > 0 && (msec < 0 || msec > p_mzq))
	{
	    towait = p_mzq;	// don't wait longer than 'mzquantum'
	    mzquantum_used = TRUE;
	}
# endif

	if (towait >= 0)
	{
	    tv.tv_sec = towait / 1000;
	    tv.tv_usec = (towait % 1000) * (1000000/1000);
	    tvp = &tv;
	}
	else
	    tvp = NULL;

	/*
	 * Select on ready for reading and exceptional condition (end of file).
	 */
select_eintr:
	FD_ZERO(&rfds);
	FD_ZERO(&wfds);
	FD_ZERO(&efds);
	FD_SET(fd, &rfds);
# ifndef __QNX__
	// For QNX select() always returns 1 if this is set.  Why?
	FD_SET(fd, &efds);
# endif
	maxfd = fd;

# ifdef FEAT_XCLIPBOARD
	may_restore_clipboard();
	if (xterm_Shell != (Widget)0)
	{
	    FD_SET(ConnectionNumber(xterm_dpy), &rfds);
	    if (maxfd < ConnectionNumber(xterm_dpy))
		maxfd = ConnectionNumber(xterm_dpy);

	    // An event may have already been read but not handled.  In
	    // particularly, XFlush may cause this.
	    xterm_update();
	}
# endif
# ifdef FEAT_MOUSE_GPM
	if (check_for_gpm != NULL && gpm_flag && gpm_fd >= 0)
	{
	    FD_SET(gpm_fd, &rfds);
	    FD_SET(gpm_fd, &efds);
	    if (maxfd < gpm_fd)
		maxfd = gpm_fd;
	}
# endif
# ifdef USE_XSMP
	if (xsmp_icefd != -1)
	{
	    FD_SET(xsmp_icefd, &rfds);
	    FD_SET(xsmp_icefd, &efds);
	    if (maxfd < xsmp_icefd)
		maxfd = xsmp_icefd;
	}
# endif
# ifdef FEAT_JOB_CHANNEL
	maxfd = channel_select_setup(maxfd, &rfds, &wfds, &tv, &tvp);
# endif
	if (interrupted != NULL)
	    *interrupted = FALSE;

	ret = select(maxfd + 1, SELECT_TYPE_ARG234 &rfds,
		      SELECT_TYPE_ARG234 &wfds, SELECT_TYPE_ARG234 &efds, tvp);
	result = ret > 0 && FD_ISSET(fd, &rfds);
	if (result)
	    --ret;
	else if (interrupted != NULL && ret > 0)
	    *interrupted = TRUE;

# ifdef EINTR
	if (ret == -1 && errno == EINTR)
	{
	    // Check whether the EINTR is caused by SIGTSTP
	    if (got_tstp && !in_mch_suspend)
	    {
		exarg_T ea;

		ea.forceit = TRUE;
		ex_stop(&ea);
		got_tstp = FALSE;
	    }

	    // Check whether window has been resized, EINTR may be caused by
	    // SIGWINCH.
	    if (do_resize)
	    {
#  ifdef FEAT_EVAL
		ch_log(NULL, "calling handle_resize() in RealWaitForChar()");
#  endif
		handle_resize();
	    }

	    // Interrupted by a signal, need to try again.  We ignore msec
	    // here, because we do want to check even after a timeout if
	    // characters are available.  Needed for reading output of an
	    // external command after the process has finished.
	    goto select_eintr;
	}
# endif
# ifdef __TANDEM
	if (ret == -1 && errno == ENOTSUP)
	{
	    FD_ZERO(&rfds);
	    FD_ZERO(&efds);
	    ret = 0;
	}
# endif
# ifdef FEAT_MZSCHEME
	if (ret == 0 && mzquantum_used)
	    // loop if MzThreads must be scheduled and timeout occurred
	    finished = FALSE;
# endif

# ifdef FEAT_XCLIPBOARD
	if (ret > 0 && xterm_Shell != (Widget)0
		&& FD_ISSET(ConnectionNumber(xterm_dpy), &rfds))
	{
	    xterm_update();	      // Maybe we should hand out clipboard
	    // continue looping when we only got the X event and the input
	    // buffer is empty
	    if (--ret == 0 && !input_available())
	    {
		// Try again
		finished = FALSE;
	    }
	}
# endif
# ifdef FEAT_MOUSE_GPM
	if (ret > 0 && check_for_gpm != NULL && gpm_flag && gpm_fd >= 0)
	{
	    if (FD_ISSET(gpm_fd, &efds))
		gpm_close();
	    else if (FD_ISSET(gpm_fd, &rfds))
		*check_for_gpm = 1;
	}
# endif
# ifdef USE_XSMP
	if (ret > 0 && xsmp_icefd != -1)
	{
	    if (FD_ISSET(xsmp_icefd, &efds))
	    {
		if (p_verbose > 0)
		    verb_msg(_("XSMP lost ICE connection"));
		xsmp_close();
		if (--ret == 0)
		    finished = FALSE;   // keep going if event was only one
	    }
	    else if (FD_ISSET(xsmp_icefd, &rfds))
	    {
		busy = TRUE;
		xsmp_handle_requests();
		busy = FALSE;
		if (--ret == 0)
		    finished = FALSE;   // keep going if event was only one
	    }
	}
# endif
#ifdef FEAT_JOB_CHANNEL
	// also call when ret == 0, we may be polling a keep-open channel
	if (ret >= 0)
	    (void)channel_select_check(ret, &rfds, &wfds);
#endif

#endif // HAVE_SELECT

#ifdef MAY_LOOP
	if (finished || msec == 0)
	    break;

# ifdef FEAT_CLIENTSERVER
	if (server_waiting())
	    break;
# endif

	// We're going to loop around again, find out for how long
	if (msec > 0)
	{
# ifdef ELAPSED_FUNC
	    // Compute remaining wait time.
	    msec = start_msec - ELAPSED_FUNC(start_tv);
# else
	    // Guess we got interrupted halfway.
	    msec = msec / 2;
# endif
	    if (msec <= 0)
		break;	// waited long enough
	}
#endif
    }

    return result;
}

/*
 * Expand a path into all matching files and/or directories.  Handles "*",
 * "?", "[a-z]", "**", etc.
 * "path" has backslashes before chars that are not to be expanded.
 * Returns the number of matches found.
 */
    int
mch_expandpath(
    garray_T	*gap,
    char_u	*path,
    int		flags)		// EW_* flags
{
    return unix_expandpath(gap, path, 0, flags, FALSE);
}

/*
 * mch_expand_wildcards() - this code does wild-card pattern matching using
 * the shell
 *
 * return OK for success, FAIL for error (you may lose some memory) and put
 * an error message in *file.
 *
 * num_pat is number of input patterns
 * pat is array of pointers to input patterns
 * num_file is pointer to number of matched file names
 * file is pointer to array of pointers to matched file names
 */

#ifndef SEEK_SET
# define SEEK_SET 0
#endif
#ifndef SEEK_END
# define SEEK_END 2
#endif

#define SHELL_SPECIAL (char_u *)"\t \"&'$;<>()\\|"

    int
mch_expand_wildcards(
    int		   num_pat,
    char_u	 **pat,
    int		  *num_file,
    char_u	***file,
    int		   flags)	// EW_* flags
{
    int		i;
    size_t	len;
    long	llen;
    char_u	*p;
    int		dir;

    /*
     * This is the non-OS/2 implementation (really Unix).
     */
    int		j;
    char_u	*tempname;
    char_u	*command;
    FILE	*fd;
    char_u	*buffer;
#define STYLE_ECHO	0	// use "echo", the default
#define STYLE_GLOB	1	// use "glob", for csh
#define STYLE_VIMGLOB	2	// use "vimglob", for Posix sh
#define STYLE_PRINT	3	// use "print -N", for zsh
#define STYLE_BT	4	// `cmd` expansion, execute the pattern directly
#define STYLE_GLOBSTAR	5	// use extended shell glob for bash (this uses extended
				// globbing functionality using globstar, needs bash > 4)
    int		shell_style = STYLE_ECHO;
    int		check_spaces;
    static int	did_find_nul = FALSE;
    int		ampersand = FALSE;
		// vimglob() function to define for Posix shell
    static char *sh_vimglob_func = "vimglob() { while [ $# -ge 1 ]; do echo \"$1\"; shift; done }; vimglob >";
		// vimglob() function with globstar setting enabled, only for bash >= 4.X
    static char *sh_globstar_opt = "[[ ${BASH_VERSINFO[0]} -ge 4 ]] && shopt -s globstar; ";

    *num_file = 0;	// default: no files found
    *file = NULL;

    /*
     * If there are no wildcards, just copy the names to allocated memory.
     * Saves a lot of time, because we don't have to start a new shell.
     */
    if (!have_wildcard(num_pat, pat))
	return save_patterns(num_pat, pat, num_file, file);

# ifdef HAVE_SANDBOX
    // Don't allow any shell command in the sandbox.
    if (sandbox != 0 && check_secure())
	return FAIL;
# endif

    /*
     * Don't allow the use of backticks in secure and restricted mode.
     */
    if (secure || restricted)
	for (i = 0; i < num_pat; ++i)
	    if (vim_strchr(pat[i], '`') != NULL
		    && (check_restricted() || check_secure()))
		return FAIL;

    /*
     * get a name for the temp file
     */
    if ((tempname = vim_tempname('o', FALSE)) == NULL)
    {
	emsg(_(e_cant_get_temp_file_name));
	return FAIL;
    }

    /*
     * Let the shell expand the patterns and write the result into the temp
     * file.
     * STYLE_BT:	NL separated
     *	    If expanding `cmd` execute it directly.
     * STYLE_GLOB:	NUL separated
     *	    If we use *csh, "glob" will work better than "echo".
     * STYLE_PRINT:	NL or NUL separated
     *	    If we use *zsh, "print -N" will work better than "glob".
     * STYLE_VIMGLOB:	NL separated
     *	    If we use *sh*, we define "vimglob()".
     * STYLE_GLOBSTAR:	NL separated
     *	    If we use *bash*, we define "vimglob() and enable globstar option".
     * STYLE_ECHO:	space separated.
     *	    A shell we don't know, stay safe and use "echo".
     */
    if (num_pat == 1 && *pat[0] == '`'
	    && (len = STRLEN(pat[0])) > 2
	    && *(pat[0] + len - 1) == '`')
	shell_style = STYLE_BT;
    else if ((len = STRLEN(p_sh)) >= 3)
    {
	if (STRCMP(p_sh + len - 3, "csh") == 0)
	    shell_style = STYLE_GLOB;
	else if (STRCMP(p_sh + len - 3, "zsh") == 0)
	    shell_style = STYLE_PRINT;
    }
    if (shell_style == STYLE_ECHO)
    {
       if (strstr((char *)gettail(p_sh), "bash") != NULL)
	    shell_style = STYLE_GLOBSTAR;
       else if (strstr((char *)gettail(p_sh), "sh") != NULL)
	    shell_style = STYLE_VIMGLOB;
    }

    // Compute the length of the command.  We need 2 extra bytes: for the
    // optional '&' and for the NUL.
    // Worst case: "unset nonomatch; print -N >" plus two is 29
    len = STRLEN(tempname) + 29;
    if (shell_style == STYLE_VIMGLOB)
	len += STRLEN(sh_vimglob_func);
    else if (shell_style == STYLE_GLOBSTAR)
	len += STRLEN(sh_vimglob_func)
	     + STRLEN(sh_globstar_opt);

    for (i = 0; i < num_pat; ++i)
    {
	// Count the length of the patterns in the same way as they are put in
	// "command" below.
#ifdef USE_SYSTEM
	len += STRLEN(pat[i]) + 3;	// add space and two quotes
#else
	++len;				// add space
	for (j = 0; pat[i][j] != NUL; ++j)
	{
	    if (vim_strchr(SHELL_SPECIAL, pat[i][j]) != NULL)
		++len;		// may add a backslash
	    ++len;
	}
#endif
    }
    command = alloc(len);
    if (command == NULL)
    {
	// out of memory
	vim_free(tempname);
	return FAIL;
    }

    /*
     * Build the shell command:
     * - Set $nonomatch depending on EW_NOTFOUND (hopefully the shell
     *	 recognizes this).
     * - Add the shell command to print the expanded names.
     * - Add the temp file name.
     * - Add the file name patterns.
     */
    if (shell_style == STYLE_BT)
    {
	// change `command; command& ` to (command; command )
	STRCPY(command, "(");
	STRCAT(command, pat[0] + 1);		// exclude first backtick
	p = command + STRLEN(command) - 1;
	*p-- = ')';				// remove last backtick
	while (p > command && VIM_ISWHITE(*p))
	    --p;
	if (*p == '&')				// remove trailing '&'
	{
	    ampersand = TRUE;
	    *p = ' ';
	}
	STRCAT(command, ">");
    }
    else
    {
	STRCPY(command, "");
	if (shell_style == STYLE_GLOB)
	{
	    // Assume the nonomatch option is valid only for csh like shells,
	    // otherwise, this may set the positional parameters for the shell,
	    // e.g. "$*".
	    if (flags & EW_NOTFOUND)
		STRCAT(command, "set nonomatch; ");
	    else
		STRCAT(command, "unset nonomatch; ");
	}
	if (shell_style == STYLE_GLOB)
	    STRCAT(command, "glob >");
	else if (shell_style == STYLE_PRINT)
	    STRCAT(command, "print -N >");
	else if (shell_style == STYLE_VIMGLOB)
	    STRCAT(command, sh_vimglob_func);
	else if (shell_style == STYLE_GLOBSTAR)
	{
	    STRCAT(command, sh_globstar_opt);
	    STRCAT(command, sh_vimglob_func);
	}
	else
	    STRCAT(command, "echo >");
    }

    STRCAT(command, tempname);

    if (shell_style != STYLE_BT)
	for (i = 0; i < num_pat; ++i)
	{
	    // When using system() always add extra quotes, because the shell
	    // is started twice.  Otherwise put a backslash before special
	    // characters, except inside ``.
#ifdef USE_SYSTEM
	    STRCAT(command, " \"");
	    STRCAT(command, pat[i]);
	    STRCAT(command, "\"");
#else
	    int intick = FALSE;

	    p = command + STRLEN(command);
	    *p++ = ' ';
	    for (j = 0; pat[i][j] != NUL; ++j)
	    {
		if (pat[i][j] == '`')
		    intick = !intick;
		else if (pat[i][j] == '\\' && pat[i][j + 1] != NUL)
		{
		    // Remove a backslash, take char literally.  But keep
		    // backslash inside backticks, before a special character
		    // and before a backtick.
		    if (intick
			  || vim_strchr(SHELL_SPECIAL, pat[i][j + 1]) != NULL
			  || pat[i][j + 1] == '`')
			*p++ = '\\';
		    ++j;
		}
		else if (!intick
			 && ((flags & EW_KEEPDOLLAR) == 0 || pat[i][j] != '$')
			      && vim_strchr(SHELL_SPECIAL, pat[i][j]) != NULL)
		    // Put a backslash before a special character, but not
		    // when inside ``. And not for $var when EW_KEEPDOLLAR is
		    // set.
		    *p++ = '\\';

		// Copy one character.
		*p++ = pat[i][j];
	    }
	    *p = NUL;
#endif
	}
    if (flags & EW_SILENT)
	show_shell_mess = FALSE;
    if (ampersand)
	STRCAT(command, "&");		// put the '&' after the redirection

    /*
     * Using zsh -G: If a pattern has no matches, it is just deleted from
     * the argument list, otherwise zsh gives an error message and doesn't
     * expand any other pattern.
     */
    if (shell_style == STYLE_PRINT)
	extra_shell_arg = (char_u *)"-G";   // Use zsh NULL_GLOB option

    /*
     * If we use -f then shell variables set in .cshrc won't get expanded.
     * vi can do it, so we will too, but it is only necessary if there is a "$"
     * in one of the patterns, otherwise we can still use the fast option.
     */
    else if (shell_style == STYLE_GLOB && !have_dollars(num_pat, pat))
	extra_shell_arg = (char_u *)"-f";	// Use csh fast option

    /*
     * execute the shell command
     */
    i = call_shell(command, SHELL_EXPAND | SHELL_SILENT);

    // When running in the background, give it some time to create the temp
    // file, but don't wait for it to finish.
    if (ampersand)
	mch_delay(10L, MCH_DELAY_IGNOREINPUT);

    extra_shell_arg = NULL;		// cleanup
    show_shell_mess = TRUE;
    vim_free(command);

    if (i != 0)				// mch_call_shell() failed
    {
	mch_remove(tempname);
	vim_free(tempname);
	/*
	 * With interactive completion, the error message is not printed.
	 * However with USE_SYSTEM, I don't know how to turn off error messages
	 * from the shell, so screen may still get messed up -- webb.
	 */
#ifndef USE_SYSTEM
	if (!(flags & EW_SILENT))
#endif
	{
	    redraw_later_clear();	// probably messed up screen
	    msg_putchar('\n');		// clear bottom line quickly
	    cmdline_row = Rows - 1;	// continue on last line
#ifdef USE_SYSTEM
	    if (!(flags & EW_SILENT))
#endif
	    {
		msg(_(e_cannot_expand_wildcards));
		msg_start();		// don't overwrite this message
	    }
	}
	// If a `cmd` expansion failed, don't list `cmd` as a match, even when
	// EW_NOTFOUND is given
	if (shell_style == STYLE_BT)
	    return FAIL;
	goto notfound;
    }

    /*
     * read the names from the file into memory
     */
    fd = fopen((char *)tempname, READBIN);
    if (fd == NULL)
    {
	// Something went wrong, perhaps a file name with a special char.
	if (!(flags & EW_SILENT))
	{
	    msg(_(e_cannot_expand_wildcards));
	    msg_start();		// don't overwrite this message
	}
	vim_free(tempname);
	goto notfound;
    }
    fseek(fd, 0L, SEEK_END);
    llen = ftell(fd);			// get size of temp file
    fseek(fd, 0L, SEEK_SET);
    if (llen < 0)
	// just in case ftell() would fail
	buffer = NULL;
    else
	buffer = alloc(llen + 1);
    if (buffer == NULL)
    {
	// out of memory
	mch_remove(tempname);
	vim_free(tempname);
	fclose(fd);
	return FAIL;
    }
    len = llen;
    i = fread((char *)buffer, 1, len, fd);
    fclose(fd);
    mch_remove(tempname);
    if (i != (int)len)
    {
	// unexpected read error
	semsg(_(e_cant_read_file_str), tempname);
	vim_free(tempname);
	vim_free(buffer);
	return FAIL;
    }
    vim_free(tempname);

# ifdef __CYGWIN__
    // Translate <CR><NL> into <NL>.  Caution, buffer may contain NUL.
    p = buffer;
    for (i = 0; i < (int)len; ++i)
	if (!(buffer[i] == CAR && buffer[i + 1] == NL))
	    *p++ = buffer[i];
    len = p - buffer;
# endif


    // file names are separated with Space
    if (shell_style == STYLE_ECHO)
    {
	buffer[len] = '\n';		// make sure the buffer ends in NL
	p = buffer;
	for (i = 0; *p != '\n'; ++i)	// count number of entries
	{
	    while (*p != ' ' && *p != '\n')
		++p;
	    p = skipwhite(p);		// skip to next entry
	}
    }
    // file names are separated with NL
    else if (shell_style == STYLE_BT ||
	    shell_style == STYLE_VIMGLOB ||
	    shell_style == STYLE_GLOBSTAR)
    {
	buffer[len] = NUL;		// make sure the buffer ends in NUL
	p = buffer;
	for (i = 0; *p != NUL; ++i)	// count number of entries
	{
	    while (*p != '\n' && *p != NUL)
		++p;
	    if (*p != NUL)
		++p;
	    p = skipwhite(p);		// skip leading white space
	}
    }
    // file names are separated with NUL
    else
    {
	/*
	 * Some versions of zsh use spaces instead of NULs to separate
	 * results.  Only do this when there is no NUL before the end of the
	 * buffer, otherwise we would never be able to use file names with
	 * embedded spaces when zsh does use NULs.
	 * When we found a NUL once, we know zsh is OK, set did_find_nul and
	 * don't check for spaces again.
	 */
	check_spaces = FALSE;
	if (shell_style == STYLE_PRINT && !did_find_nul)
	{
	    // If there is a NUL, set did_find_nul, else set check_spaces
	    buffer[len] = NUL;
	    if (len && (int)STRLEN(buffer) < (int)len)
		did_find_nul = TRUE;
	    else
		check_spaces = TRUE;
	}

	/*
	 * Make sure the buffer ends with a NUL.  For STYLE_PRINT there
	 * already is one, for STYLE_GLOB it needs to be added.
	 */
	if (len && buffer[len - 1] == NUL)
	    --len;
	else
	    buffer[len] = NUL;
	i = 0;
	for (p = buffer; p < buffer + len; ++p)
	    if (*p == NUL || (*p == ' ' && check_spaces))   // count entry
	    {
		++i;
		*p = NUL;
	    }
	if (len)
	    ++i;			// count last entry
    }
    if (i == 0)
    {
	/*
	 * Can happen when using /bin/sh and typing ":e $NO_SUCH_VAR^I".
	 * /bin/sh will happily expand it to nothing rather than returning an
	 * error; and hey, it's good to check anyway -- webb.
	 */
	vim_free(buffer);
	goto notfound;
    }
    *num_file = i;
    *file = ALLOC_MULT(char_u *, i);
    if (*file == NULL)
    {
	// out of memory
	vim_free(buffer);
	return FAIL;
    }

    /*
     * Isolate the individual file names.
     */
    p = buffer;
    for (i = 0; i < *num_file; ++i)
    {
	(*file)[i] = p;
	// Space or NL separates
	if (shell_style == STYLE_ECHO || shell_style == STYLE_BT
		|| shell_style == STYLE_VIMGLOB || shell_style == STYLE_GLOBSTAR)
	{
	    while (!(shell_style == STYLE_ECHO && *p == ' ')
						   && *p != '\n' && *p != NUL)
		++p;
	    if (p == buffer + len)		// last entry
		*p = NUL;
	    else
	    {
		*p++ = NUL;
		p = skipwhite(p);		// skip to next entry
	    }
	}
	else		// NUL separates
	{
	    while (*p && p < buffer + len)	// skip entry
		++p;
	    ++p;				// skip NUL
	}
    }

    /*
     * Move the file names to allocated memory.
     */
    for (j = 0, i = 0; i < *num_file; ++i)
    {
	// Require the files to exist.	Helps when using /bin/sh
	if (!(flags & EW_NOTFOUND) && mch_getperm((*file)[i]) < 0)
	    continue;

	// check if this entry should be included
	dir = (mch_isdir((*file)[i]));
	if ((dir && !(flags & EW_DIR)) || (!dir && !(flags & EW_FILE)))
	    continue;

	// Skip files that are not executable if we check for that.
	if (!dir && (flags & EW_EXEC)
		    && !mch_can_exe((*file)[i], NULL, !(flags & EW_SHELLCMD)))
	    continue;

	p = alloc(STRLEN((*file)[i]) + 1 + dir);
	if (p)
	{
	    STRCPY(p, (*file)[i]);
	    if (dir)
		add_pathsep(p);	    // add '/' to a directory name
	    (*file)[j++] = p;
	}
    }
    vim_free(buffer);
    *num_file = j;

    if (*num_file == 0)	    // rejected all entries
    {
	VIM_CLEAR(*file);
	goto notfound;
    }

    return OK;

notfound:
    if (flags & EW_NOTFOUND)
	return save_patterns(num_pat, pat, num_file, file);
    return FAIL;
}

#endif // VMS

    static int
save_patterns(
    int		num_pat,
    char_u	**pat,
    int		*num_file,
    char_u	***file)
{
    int		i;
    char_u	*s;

    *file = ALLOC_MULT(char_u *, num_pat);
    if (*file == NULL)
	return FAIL;
    for (i = 0; i < num_pat; i++)
    {
	s = vim_strsave(pat[i]);
	if (s != NULL)
	    // Be compatible with expand_filename(): halve the number of
	    // backslashes.
	    backslash_halve(s);
	(*file)[i] = s;
    }
    *num_file = num_pat;
    return OK;
}

/*
 * Return TRUE if the string "p" contains a wildcard that mch_expandpath() can
 * expand.
 */
    int
mch_has_exp_wildcard(char_u *p)
{
    for ( ; *p; MB_PTR_ADV(p))
    {
	if (*p == '\\' && p[1] != NUL)
	    ++p;
	else
	    if (vim_strchr((char_u *)
#ifdef VMS
				    "*?%"
#else
				    "*?[{'"
#endif
						, *p) != NULL)
	    return TRUE;
    }
    return FALSE;
}

/*
 * Return TRUE if the string "p" contains a wildcard.
 * Don't recognize '~' at the end as a wildcard.
 */
    int
mch_has_wildcard(char_u *p)
{
    for ( ; *p; MB_PTR_ADV(p))
    {
	if (*p == '\\' && p[1] != NUL)
	    ++p;
	else
	    if (vim_strchr((char_u *)
#ifdef VMS
				    "*?%$"
#else
				    "*?[{`'$"
#endif
						, *p) != NULL
		|| (*p == '~' && p[1] != NUL))
	    return TRUE;
    }
    return FALSE;
}

    static int
have_wildcard(int num, char_u **file)
{
    int	    i;

    for (i = 0; i < num; i++)
	if (mch_has_wildcard(file[i]))
	    return 1;
    return 0;
}

    static int
have_dollars(int num, char_u **file)
{
    int	    i;

    for (i = 0; i < num; i++)
	if (vim_strchr(file[i], '$') != NULL)
	    return TRUE;
    return FALSE;
}

#if !defined(HAVE_RENAME) || defined(PROTO)
/*
 * Scaled-down version of rename(), which is missing in Xenix.
 * This version can only move regular files and will fail if the
 * destination exists.
 */
    int
mch_rename(const char *src, const char *dest)
{
    struct stat	    st;

    if (stat(dest, &st) >= 0)	    // fail if destination exists
	return -1;
    if (link(src, dest) != 0)	    // link file to new name
	return -1;
    if (mch_remove(src) == 0)	    // delete link to old name
	return 0;
    return -1;
}
#endif // !HAVE_RENAME

#if defined(FEAT_MOUSE_GPM) || defined(PROTO)
# if defined(DYNAMIC_GPM) || defined(PROTO)
/*
 * Initialize Gpm's symbols for dynamic linking.
 * Must be called only if libgpm_hinst is NULL.
 */
    static int
load_libgpm(void)
{
    libgpm_hinst = dlopen("libgpm.so", RTLD_LAZY|RTLD_GLOBAL);

    if (libgpm_hinst == NULL)
    {
	if (p_verbose > 0)
	    smsg_attr(HL_ATTR(HLF_W),
			       _("Could not load gpm library: %s"), dlerror());
	return FAIL;
    }

    if (
	    (dll_Gpm_Open     = dlsym(libgpm_hinst, "Gpm_Open"))     == NULL
	||  (dll_Gpm_Close    = dlsym(libgpm_hinst, "Gpm_Close"))    == NULL
	||  (dll_Gpm_GetEvent = dlsym(libgpm_hinst, "Gpm_GetEvent")) == NULL
	||  (dll_gpm_flag     = dlsym(libgpm_hinst, "gpm_flag"))     == NULL
	||  (dll_gpm_fd       = dlsym(libgpm_hinst, "gpm_fd"))       == NULL
      )
    {
	semsg(_(e_could_not_load_library_str_str), "gpm", dlerror());
	dlclose(libgpm_hinst);
	libgpm_hinst = NULL;
	dll_gpm_flag = NULL;
	dll_gpm_fd   = NULL;
	return FAIL;
    }
    return OK;
}

    int
gpm_available(void)
{
    return libgpm_hinst != NULL || load_libgpm() == OK;
}
# endif // DYNAMIC_GPM

/*
 * Initializes connection with gpm (if it isn't already opened)
 * Return 1 if succeeded (or connection already opened), 0 if failed
 */
    static int
gpm_open(void)
{
    static Gpm_Connect gpm_connect; // Must it be kept till closing ?

#ifdef DYNAMIC_GPM
    if (!gpm_available())
	return 0;
#endif

    if (gpm_flag)
	return 1; // already open

    gpm_connect.eventMask = (GPM_UP | GPM_DRAG | GPM_DOWN);
    gpm_connect.defaultMask = ~GPM_HARD;
    // Default handling for mouse move
    gpm_connect.minMod = 0; // Handle any modifier keys
    gpm_connect.maxMod = 0xffff;
    if (Gpm_Open(&gpm_connect, 0) > 0)
    {
	// gpm library tries to handling TSTP causes
	// problems. Anyways, we close connection to Gpm whenever
	// we are going to suspend or starting an external process
	// so we shouldn't  have problem with this
# ifdef SIGTSTP
	mch_signal(SIGTSTP, restricted ? SIG_IGN : sig_tstp);
# endif
	return 1; // succeed
    }
    if (gpm_fd == -2)
    {
	Gpm_Close(); // We don't want to talk to xterm via gpm

        // Gpm_Close fails to properly restore the WINCH and TSTP handlers,
        // leading to Vim ignoring resize signals. We have to re-initialize
        // these handlers again here.
# ifdef SIGWINCH
	mch_signal(SIGWINCH, sig_winch);
# endif
# ifdef SIGTSTP
	mch_signal(SIGTSTP, restricted ? SIG_IGN : sig_tstp);
# endif
    }
    return 0;
}

/*
 * Returns TRUE if the GPM mouse is enabled.
 */
    int
gpm_enabled(void)
{
    return gpm_flag && gpm_fd >= 0;
}

/*
 * Closes connection to gpm
 */
    static void
gpm_close(void)
{
    if (gpm_enabled())
	Gpm_Close();
}

/*
 * Reads gpm event and adds special keys to input buf. Returns length of
 * generated key sequence.
 * This function is styled after gui_send_mouse_event().
 */
    static int
mch_gpm_process(void)
{
    int			button;
    static Gpm_Event	gpm_event;
    char_u		string[6];
    int_u		vim_modifiers;
    int			row,col;
    unsigned char	buttons_mask;
    unsigned char	gpm_modifiers;
    static unsigned char old_buttons = 0;

    Gpm_GetEvent(&gpm_event);

#ifdef FEAT_GUI
    // Don't put events in the input queue now.
    if (hold_gui_events)
	return 0;
#endif

    row = gpm_event.y - 1;
    col = gpm_event.x - 1;

    string[0] = ESC; // Our termcode
    string[1] = 'M';
    string[2] = 'G';
    switch (GPM_BARE_EVENTS(gpm_event.type))
    {
	case GPM_DRAG:
	    string[3] = MOUSE_DRAG;
	    break;
	case GPM_DOWN:
	    buttons_mask = gpm_event.buttons & ~old_buttons;
	    old_buttons = gpm_event.buttons;
	    switch (buttons_mask)
	    {
		case GPM_B_LEFT:
		    button = MOUSE_LEFT;
		    break;
		case GPM_B_MIDDLE:
		    button = MOUSE_MIDDLE;
		    break;
		case GPM_B_RIGHT:
		    button = MOUSE_RIGHT;
		    break;
		default:
		    return 0;
		    // Don't know what to do. Can more than one button be
		    // reported in one event?
	    }
	    string[3] = (char_u)(button | 0x20);
	    SET_NUM_MOUSE_CLICKS(string[3], gpm_event.clicks + 1);
	    break;
	case GPM_UP:
	    string[3] = MOUSE_RELEASE;
	    old_buttons &= ~gpm_event.buttons;
	    break;
	default:
	    return 0;
    }
    // This code is based on gui_x11_mouse_cb in gui_x11.c
    gpm_modifiers = gpm_event.modifiers;
    vim_modifiers = 0x0;
    // I ignore capslock stats. Aren't we all just hate capslock mixing with
    // Vim commands ? Besides, gpm_event.modifiers is unsigned char, and
    // K_CAPSSHIFT is defined 8, so it probably isn't even reported
    if (gpm_modifiers & ((1 << KG_SHIFT) | (1 << KG_SHIFTR) | (1 << KG_SHIFTL)))
	vim_modifiers |= MOUSE_SHIFT;

    if (gpm_modifiers & ((1 << KG_CTRL) | (1 << KG_CTRLR) | (1 << KG_CTRLL)))
	vim_modifiers |= MOUSE_CTRL;
    if (gpm_modifiers & ((1 << KG_ALT) | (1 << KG_ALTGR)))
	vim_modifiers |= MOUSE_ALT;
    string[3] |= vim_modifiers;
    string[4] = (char_u)(col + ' ' + 1);
    string[5] = (char_u)(row + ' ' + 1);
    add_to_input_buf(string, 6);
    return 6;
}
#endif // FEAT_MOUSE_GPM

#ifdef FEAT_SYSMOUSE
/*
 * Initialize connection with sysmouse.
 * Let virtual console inform us with SIGUSR2 for pending sysmouse
 * output, any sysmouse output than will be processed via sig_sysmouse().
 * Return OK if succeeded, FAIL if failed.
 */
    static int
sysmouse_open(void)
{
    struct mouse_info   mouse;

    mouse.operation = MOUSE_MODE;
    mouse.u.mode.mode = 0;
    mouse.u.mode.signal = SIGUSR2;
    if (ioctl(1, CONS_MOUSECTL, &mouse) == -1)
	return FAIL;

    mch_signal(SIGUSR2, sig_sysmouse);
    mouse.operation = MOUSE_SHOW;
    ioctl(1, CONS_MOUSECTL, &mouse);
    return OK;
}

/*
 * Stop processing SIGUSR2 signals, and also make sure that
 * virtual console do not send us any sysmouse related signal.
 */
    static void
sysmouse_close(void)
{
    struct mouse_info	mouse;

    mch_signal(SIGUSR2, restricted ? SIG_IGN : SIG_DFL);
    mouse.operation = MOUSE_MODE;
    mouse.u.mode.mode = 0;
    mouse.u.mode.signal = 0;
    ioctl(1, CONS_MOUSECTL, &mouse);
}

/*
 * Gets info from sysmouse and adds special keys to input buf.
 */
    static void
sig_sysmouse SIGDEFARG(sigarg)
{
    struct mouse_info	mouse;
    struct video_info	video;
    char_u		string[6];
    int			row, col;
    int			button;
    int			buttons;
    static int		oldbuttons = 0;

#ifdef FEAT_GUI
    // Don't put events in the input queue now.
    if (hold_gui_events)
	return;
#endif

    mouse.operation = MOUSE_GETINFO;
    if (ioctl(1, FBIO_GETMODE, &video.vi_mode) != -1
	    && ioctl(1, FBIO_MODEINFO, &video) != -1
	    && ioctl(1, CONS_MOUSECTL, &mouse) != -1
	    && video.vi_cheight > 0 && video.vi_cwidth > 0)
    {
	row = mouse.u.data.y / video.vi_cheight;
	col = mouse.u.data.x / video.vi_cwidth;
	buttons = mouse.u.data.buttons;
	string[0] = ESC; // Our termcode
	string[1] = 'M';
	string[2] = 'S';
	if (oldbuttons == buttons && buttons != 0)
	{
	    button = MOUSE_DRAG;
	}
	else
	{
	    switch (buttons)
	    {
		case 0:
		    button = MOUSE_RELEASE;
		    break;
		case 1:
		    button = MOUSE_LEFT;
		    break;
		case 2:
		    button = MOUSE_MIDDLE;
		    break;
		case 4:
		    button = MOUSE_RIGHT;
		    break;
		default:
		    return;
	    }
	    oldbuttons = buttons;
	}
	string[3] = (char_u)(button);
	string[4] = (char_u)(col + ' ' + 1);
	string[5] = (char_u)(row + ' ' + 1);
	add_to_input_buf(string, 6);
    }
    return;
}
#endif // FEAT_SYSMOUSE

#if defined(FEAT_LIBCALL) || defined(PROTO)
typedef char_u * (*STRPROCSTR)(char_u *);
typedef char_u * (*INTPROCSTR)(int);
typedef int (*STRPROCINT)(char_u *);
typedef int (*INTPROCINT)(int);

/*
 * Call a DLL routine which takes either a string or int param
 * and returns an allocated string.
 */
    int
mch_libcall(
    char_u	*libname,
    char_u	*funcname,
    char_u	*argstring,	// NULL when using a argint
    int		argint,
    char_u	**string_result, // NULL when using number_result
    int		*number_result)
{
# if defined(USE_DLOPEN)
    void	*hinstLib;
    char	*dlerr = NULL;
# else
    shl_t	hinstLib;
# endif
    STRPROCSTR	ProcAdd;
    INTPROCSTR	ProcAddI;
    char_u	*retval_str = NULL;
    int		retval_int = 0;
    int		success = FALSE;

    /*
     * Get a handle to the DLL module.
     */
# if defined(USE_DLOPEN)
    // First clear any error, it's not cleared by the dlopen() call.
    (void)dlerror();

    hinstLib = dlopen((char *)libname, RTLD_LAZY
#  ifdef RTLD_LOCAL
	    | RTLD_LOCAL
#  endif
	    );
    if (hinstLib == NULL)
    {
	// "dlerr" must be used before dlclose()
	dlerr = dlerror();
	if (dlerr != NULL)
	    semsg(_("dlerror = \"%s\""), dlerr);
    }
# else
    hinstLib = shl_load((const char*)libname, BIND_IMMEDIATE|BIND_VERBOSE, 0L);
# endif

    // If the handle is valid, try to get the function address.
    if (hinstLib != NULL)
    {
# ifdef USING_SETJMP
	/*
	 * Catch a crash when calling the library function.  For example when
	 * using a number where a string pointer is expected.
	 */
	mch_startjmp();
	if (SETJMP(lc_jump_env) != 0)
	{
	    success = FALSE;
#  if defined(USE_DLOPEN)
	    dlerr = NULL;
#  endif
	    mch_didjmp();
	}
	else
# endif
	{
	    retval_str = NULL;
	    retval_int = 0;

	    if (argstring != NULL)
	    {
# if defined(USE_DLOPEN)
		*(void **)(&ProcAdd) = dlsym(hinstLib, (const char *)funcname);
		dlerr = dlerror();
# else
		if (shl_findsym(&hinstLib, (const char *)funcname,
					TYPE_PROCEDURE, (void *)&ProcAdd) < 0)
		    ProcAdd = NULL;
# endif
		if ((success = (ProcAdd != NULL
# if defined(USE_DLOPEN)
			    && dlerr == NULL
# endif
			    )))
		{
		    if (string_result == NULL)
			retval_int = ((STRPROCINT)(void *)ProcAdd)(argstring);
		    else
			retval_str = (ProcAdd)(argstring);
		}
	    }
	    else
	    {
# if defined(USE_DLOPEN)
		*(void **)(&ProcAddI) = dlsym(hinstLib, (const char *)funcname);
		dlerr = dlerror();
# else
		if (shl_findsym(&hinstLib, (const char *)funcname,
				       TYPE_PROCEDURE, (void *)&ProcAddI) < 0)
		    ProcAddI = NULL;
# endif
		if ((success = (ProcAddI != NULL
# if defined(USE_DLOPEN)
			    && dlerr == NULL
# endif
			    )))
		{
		    if (string_result == NULL)
			retval_int = ((INTPROCINT)(void *)ProcAddI)(argint);
		    else
			retval_str = (ProcAddI)(argint);
		}
	    }

	    // Save the string before we free the library.
	    // Assume that a "1" or "-1" result is an illegal pointer.
	    if (string_result == NULL)
		*number_result = retval_int;
	    else if (retval_str != NULL
		    && retval_str != (char_u *)1
		    && retval_str != (char_u *)-1)
		*string_result = vim_strsave(retval_str);
	}

# ifdef USING_SETJMP
	mch_endjmp();
#  ifdef SIGHASARG
	if (lc_signal != 0)
	{
	    int i;

	    // try to find the name of this signal
	    for (i = 0; signal_info[i].sig != -1; i++)
		if (lc_signal == signal_info[i].sig)
		    break;
	    semsg(_(e_got_sig_str_in_libcall), signal_info[i].name);
	}
#  endif
# endif

# if defined(USE_DLOPEN)
	// "dlerr" must be used before dlclose()
	if (dlerr != NULL)
	    semsg(_("dlerror = \"%s\""), dlerr);

	// Free the DLL module.
	(void)dlclose(hinstLib);
# else
	(void)shl_unload(hinstLib);
# endif
    }

    if (!success)
    {
	semsg(_(e_library_call_failed_for_str), funcname);
	return FAIL;
    }

    return OK;
}
#endif

#if (defined(FEAT_X11) && defined(FEAT_XCLIPBOARD)) || defined(PROTO)
static int	xterm_trace = -1;	// default: disabled
static int	xterm_button;

/*
 * Setup a dummy window for X selections in a terminal.
 */
    void
setup_term_clip(void)
{
    int		z = 0;
    char	*strp = "";
    Widget	AppShell;

    if (!x_connect_to_server())
	return;

    open_app_context();
    if (app_context != NULL && xterm_Shell == (Widget)0)
    {
	int (*oldhandler)(Display*, XErrorEvent*);
# if defined(USING_SETJMP)
	int (*oldIOhandler)(Display*);
# endif
# ifdef ELAPSED_FUNC
	elapsed_T start_tv;

	if (p_verbose > 0)
	    ELAPSED_INIT(start_tv);
# endif

	// Ignore X errors while opening the display
	oldhandler = XSetErrorHandler(x_error_check);

# if defined(USING_SETJMP)
	// Ignore X IO errors while opening the display
	oldIOhandler = XSetIOErrorHandler(x_IOerror_check);
	mch_startjmp();
	if (SETJMP(lc_jump_env) != 0)
	{
	    mch_didjmp();
	    xterm_dpy = NULL;
	}
	else
# endif
	{
	    xterm_dpy = XtOpenDisplay(app_context, xterm_display,
		    "vim_xterm", "Vim_xterm", NULL, 0, &z, &strp);
	    if (xterm_dpy != NULL)
		xterm_dpy_retry_count = 0;
# if defined(USING_SETJMP)
	    mch_endjmp();
# endif
	}

# if defined(USING_SETJMP)
	// Now handle X IO errors normally.
	(void)XSetIOErrorHandler(oldIOhandler);
# endif
	// Now handle X errors normally.
	(void)XSetErrorHandler(oldhandler);

	if (xterm_dpy == NULL)
	{
	    if (p_verbose > 0)
		verb_msg(_("Opening the X display failed"));
	    return;
	}

	// Catch terminating error of the X server connection.
	(void)XSetIOErrorHandler(x_IOerror_handler);

# ifdef ELAPSED_FUNC
	if (p_verbose > 0)
	{
	    verbose_enter();
	    xopen_message(ELAPSED_FUNC(start_tv));
	    verbose_leave();
	}
# endif

	// Create a Shell to make converters work.
	AppShell = XtVaAppCreateShell("vim_xterm", "Vim_xterm",
		applicationShellWidgetClass, xterm_dpy,
		NULL);
	if (AppShell == (Widget)0)
	    return;
	xterm_Shell = XtVaCreatePopupShell("VIM",
		topLevelShellWidgetClass, AppShell,
		XtNmappedWhenManaged, 0,
		XtNwidth, 1,
		XtNheight, 1,
		NULL);
	if (xterm_Shell == (Widget)0)
	    return;

	x11_setup_atoms(xterm_dpy);
	x11_setup_selection(xterm_Shell);
	if (x11_display == NULL)
	    x11_display = xterm_dpy;

	XtRealizeWidget(xterm_Shell);
	XSync(xterm_dpy, False);
	xterm_update();
    }
    if (xterm_Shell != (Widget)0)
    {
	clip_init(TRUE);
	if (x11_window == 0 && (strp = getenv("WINDOWID")) != NULL)
	    x11_window = (Window)atol(strp);
	// Check if $WINDOWID is valid.
	if (test_x11_window(xterm_dpy) == FAIL)
	    x11_window = 0;
	if (x11_window != 0)
	    xterm_trace = 0;
    }
}

    void
start_xterm_trace(int button)
{
    if (x11_window == 0 || xterm_trace < 0 || xterm_Shell == (Widget)0)
	return;
    xterm_trace = 1;
    xterm_button = button;
    do_xterm_trace();
}


    void
stop_xterm_trace(void)
{
    if (xterm_trace < 0)
	return;
    xterm_trace = 0;
}

/*
 * Query the xterm pointer and generate mouse termcodes if necessary
 * return TRUE if dragging is active, else FALSE
 */
    static int
do_xterm_trace(void)
{
    Window		root, child;
    int			root_x, root_y;
    int			win_x, win_y;
    int			row, col;
    int_u		mask_return;
    char_u		buf[50];
    char_u		*strp;
    long		got_hints;
    static char_u	*mouse_code;
    static char_u	mouse_name[2] = {KS_MOUSE, KE_FILLER};
    static int		prev_row = 0, prev_col = 0;
    static XSizeHints	xterm_hints;

    if (xterm_trace <= 0)
	return FALSE;

    if (xterm_trace == 1)
    {
	// Get the hints just before tracking starts.  The font size might
	// have changed recently.
	if (!XGetWMNormalHints(xterm_dpy, x11_window, &xterm_hints, &got_hints)
		|| !(got_hints & PResizeInc)
		|| xterm_hints.width_inc <= 1
		|| xterm_hints.height_inc <= 1)
	{
	    xterm_trace = -1;  // Not enough data -- disable tracing
	    return FALSE;
	}

	// Rely on the same mouse code for the duration of this
	mouse_code = find_termcode(mouse_name);
	prev_row = mouse_row;
	prev_col = mouse_col;
	xterm_trace = 2;

	// Find the offset of the chars, there might be a scrollbar on the
	// left of the window and/or a menu on the top (eterm etc.)
	XQueryPointer(xterm_dpy, x11_window, &root, &child, &root_x, &root_y,
		      &win_x, &win_y, &mask_return);
	xterm_hints.y = win_y - (xterm_hints.height_inc * mouse_row)
			      - (xterm_hints.height_inc / 2);
	if (xterm_hints.y <= xterm_hints.height_inc / 2)
	    xterm_hints.y = 2;
	xterm_hints.x = win_x - (xterm_hints.width_inc * mouse_col)
			      - (xterm_hints.width_inc / 2);
	if (xterm_hints.x <= xterm_hints.width_inc / 2)
	    xterm_hints.x = 2;
	return TRUE;
    }
    if (mouse_code == NULL || STRLEN(mouse_code) > 45)
    {
	xterm_trace = 0;
	return FALSE;
    }

    XQueryPointer(xterm_dpy, x11_window, &root, &child, &root_x, &root_y,
		  &win_x, &win_y, &mask_return);

    row = check_row((win_y - xterm_hints.y) / xterm_hints.height_inc);
    col = check_col((win_x - xterm_hints.x) / xterm_hints.width_inc);
    if (row == prev_row && col == prev_col)
	return TRUE;

    STRCPY(buf, mouse_code);
    strp = buf + STRLEN(buf);
    *strp++ = (xterm_button | MOUSE_DRAG) & ~0x20;
    *strp++ = (char_u)(col + ' ' + 1);
    *strp++ = (char_u)(row + ' ' + 1);
    *strp = 0;
    add_to_input_buf(buf, STRLEN(buf));

    prev_row = row;
    prev_col = col;
    return TRUE;
}

# if defined(FEAT_GUI) || defined(FEAT_XCLIPBOARD) || defined(PROTO)
/*
 * Destroy the display, window and app_context.  Required for GTK.
 */
    void
clear_xterm_clip(void)
{
    if (xterm_Shell != (Widget)0)
    {
	XtDestroyWidget(xterm_Shell);
	xterm_Shell = (Widget)0;
    }
    if (xterm_dpy != NULL)
    {
#  if 0
	// Lesstif and Solaris crash here, lose some memory
	XtCloseDisplay(xterm_dpy);
#  endif
	if (x11_display == xterm_dpy)
	    x11_display = NULL;
	xterm_dpy = NULL;
    }
#  if 0
    if (app_context != (XtAppContext)NULL)
    {
	// Lesstif and Solaris crash here, lose some memory
	XtDestroyApplicationContext(app_context);
	app_context = (XtAppContext)NULL;
    }
#  endif
}
# endif

/*
 * Catch up with GUI or X events.
 */
    static void
clip_update(void)
{
# ifdef FEAT_GUI
    if (gui.in_use)
	gui_mch_update();
    else
# endif
    if (xterm_Shell != (Widget)0)
	xterm_update();
}

/*
 * Catch up with any queued X events.  This may put keyboard input into the
 * input buffer, call resize call-backs, trigger timers etc.  If there is
 * nothing in the X event queue (& no timers pending), then we return
 * immediately.
 */
    static void
xterm_update(void)
{
    XEvent event;

    for (;;)
    {
	XtInputMask mask = XtAppPending(app_context);

	if (mask == 0 || vim_is_input_buf_full())
	    break;

	if (mask & XtIMXEvent)
	{
	    // There is an event to process.
	    XtAppNextEvent(app_context, &event);
#ifdef FEAT_CLIENTSERVER
	    {
		XPropertyEvent *e = (XPropertyEvent *)&event;

		if (e->type == PropertyNotify && e->window == commWindow
		   && e->atom == commProperty && e->state == PropertyNewValue)
		    serverEventProc(xterm_dpy, &event, 0);
	    }
#endif
	    XtDispatchEvent(&event);
	}
	else
	{
	    // There is something else than an event to process.
	    XtAppProcessEvent(app_context, mask);
	}
    }
}

    int
clip_xterm_own_selection(Clipboard_T *cbd)
{
    if (xterm_Shell != (Widget)0)
	return clip_x11_own_selection(xterm_Shell, cbd);
    return FAIL;
}

    void
clip_xterm_lose_selection(Clipboard_T *cbd)
{
    if (xterm_Shell != (Widget)0)
	clip_x11_lose_selection(xterm_Shell, cbd);
}

    void
clip_xterm_request_selection(Clipboard_T *cbd)
{
    if (xterm_Shell != (Widget)0)
	clip_x11_request_selection(xterm_Shell, xterm_dpy, cbd);
}

    void
clip_xterm_set_selection(Clipboard_T *cbd)
{
    clip_x11_set_selection(cbd);
}
#endif


#if defined(USE_XSMP) || defined(PROTO)
/*
 * Code for X Session Management Protocol.
 */

# if defined(FEAT_GUI) && defined(USE_XSMP_INTERACT)
/*
 * This is our chance to ask the user if they want to save,
 * or abort the logout
 */
    static void
xsmp_handle_interaction(SmcConn smc_conn, SmPointer client_data UNUSED)
{
    int		save_cmod_flags;
    int		cancel_shutdown = False;

    save_cmod_flags = cmdmod.cmod_flags;
    cmdmod.cmod_flags |= CMOD_CONFIRM;
    if (check_changed_any(FALSE, FALSE))
	// Mustn't logout
	cancel_shutdown = True;
    cmdmod.cmod_flags = save_cmod_flags;
    setcursor();		// position cursor
    out_flush();

    // Done interaction
    SmcInteractDone(smc_conn, cancel_shutdown);

    // Finish off
    // Only end save-yourself here if we're not cancelling shutdown;
    // we'll get a cancelled callback later in which we'll end it.
    // Hopefully get around glitchy SMs (like GNOME-1)
    if (!cancel_shutdown)
    {
	xsmp.save_yourself = False;
	SmcSaveYourselfDone(smc_conn, True);
    }
}
# endif

/*
 * Callback that starts save-yourself.
 */
    static void
xsmp_handle_save_yourself(
    SmcConn	smc_conn,
    SmPointer	client_data UNUSED,
    int		save_type UNUSED,
    Bool	shutdown,
    int		interact_style UNUSED,
    Bool	fast UNUSED)
{
    // Handle already being in saveyourself
    if (xsmp.save_yourself)
	SmcSaveYourselfDone(smc_conn, True);
    xsmp.save_yourself = True;
    xsmp.shutdown = shutdown;

    // First up, preserve all files
    out_flush();
    ml_sync_all(FALSE, FALSE);	// preserve all swap files

    if (p_verbose > 0)
	verb_msg(_("XSMP handling save-yourself request"));

# if defined(FEAT_GUI) && defined(USE_XSMP_INTERACT)
    // Now see if we can ask about unsaved files
    if (shutdown && !fast && gui.in_use)
	// Need to interact with user, but need SM's permission
	SmcInteractRequest(smc_conn, SmDialogError,
					xsmp_handle_interaction, client_data);
    else
# endif
    {
	// Can stop the cycle here
	SmcSaveYourselfDone(smc_conn, True);
	xsmp.save_yourself = False;
    }
}


/*
 * Callback to warn us of imminent death.
 */
    static void
xsmp_die(SmcConn smc_conn UNUSED, SmPointer client_data UNUSED)
{
    xsmp_close();

    // quit quickly leaving swapfiles for modified buffers behind
    getout_preserve_modified(0);
}


/*
 * Callback to tell us that save-yourself has completed.
 */
    static void
xsmp_save_complete(
    SmcConn	smc_conn UNUSED,
    SmPointer	client_data UNUSED)
{
    xsmp.save_yourself = False;
}


/*
 * Callback to tell us that an instigated shutdown was cancelled
 * (maybe even by us)
 */
    static void
xsmp_shutdown_cancelled(
    SmcConn	smc_conn,
    SmPointer	client_data UNUSED)
{
    if (xsmp.save_yourself)
	SmcSaveYourselfDone(smc_conn, True);
    xsmp.save_yourself = False;
    xsmp.shutdown = False;
}


/*
 * Callback to tell us that a new ICE connection has been established.
 */
    static void
xsmp_ice_connection(
    IceConn	iceConn,
    IcePointer	clientData UNUSED,
    Bool	opening,
    IcePointer	*watchData UNUSED)
{
    // Intercept creation of ICE connection fd
    if (opening)
    {
	xsmp_icefd = IceConnectionNumber(iceConn);
	IceRemoveConnectionWatch(xsmp_ice_connection, NULL);
    }
}


// Handle any ICE processing that's required; return FAIL if SM lost
    int
xsmp_handle_requests(void)
{
    Bool rep;

    if (IceProcessMessages(xsmp.iceconn, NULL, &rep)
						 == IceProcessMessagesIOError)
    {
	// Lost ICE
	if (p_verbose > 0)
	    verb_msg(_("XSMP lost ICE connection"));
	xsmp_close();
	return FAIL;
    }
    else
	return OK;
}

static int dummy;

// Set up X Session Management Protocol
    void
xsmp_init(void)
{
    char		errorstring[80];
    SmcCallbacks	smcallbacks;
#if 0
    SmPropValue		smname;
    SmProp		smnameprop;
    SmProp		*smprops[1];
#endif

    if (p_verbose > 0)
	verb_msg(_("XSMP opening connection"));

    xsmp.save_yourself = xsmp.shutdown = False;

    // Set up SM callbacks - must have all, even if they're not used
    smcallbacks.save_yourself.callback = xsmp_handle_save_yourself;
    smcallbacks.save_yourself.client_data = NULL;
    smcallbacks.die.callback = xsmp_die;
    smcallbacks.die.client_data = NULL;
    smcallbacks.save_complete.callback = xsmp_save_complete;
    smcallbacks.save_complete.client_data = NULL;
    smcallbacks.shutdown_cancelled.callback = xsmp_shutdown_cancelled;
    smcallbacks.shutdown_cancelled.client_data = NULL;

    // Set up a watch on ICE connection creations.  The "dummy" argument is
    // apparently required for FreeBSD (we get a BUS error when using NULL).
    if (IceAddConnectionWatch(xsmp_ice_connection, &dummy) == 0)
    {
	if (p_verbose > 0)
	    verb_msg(_("XSMP ICE connection watch failed"));
	return;
    }

    // Create an SM connection
    xsmp.smcconn = SmcOpenConnection(
	    NULL,
	    NULL,
	    SmProtoMajor,
	    SmProtoMinor,
	    SmcSaveYourselfProcMask | SmcDieProcMask
		     | SmcSaveCompleteProcMask | SmcShutdownCancelledProcMask,
	    &smcallbacks,
	    NULL,
	    &xsmp.clientid,
	    sizeof(errorstring) - 1,
	    errorstring);
    if (xsmp.smcconn == NULL)
    {
	if (p_verbose > 0)
	{
	    char errorreport[132];

	    // If the message is too long it might not be NUL terminated.  Add
	    // a NUL at the end to make sure we don't go over the end.
	    errorstring[sizeof(errorstring) - 1] = NUL;
	    vim_snprintf(errorreport, sizeof(errorreport),
			 _("XSMP SmcOpenConnection failed: %s"), errorstring);
	    verb_msg(errorreport);
	}
	return;
    }
    xsmp.iceconn = SmcGetIceConnection(xsmp.smcconn);

#if 0
    // ID ourselves
    smname.value = "vim";
    smname.length = 3;
    smnameprop.name = "SmProgram";
    smnameprop.type = "SmARRAY8";
    smnameprop.num_vals = 1;
    smnameprop.vals = &smname;

    smprops[0] = &smnameprop;
    SmcSetProperties(xsmp.smcconn, 1, smprops);
#endif
}


// Shut down XSMP comms.
    void
xsmp_close(void)
{
    if (xsmp_icefd == -1)
	return;

    SmcCloseConnection(xsmp.smcconn, 0, NULL);
    if (xsmp.clientid != NULL)
	free(xsmp.clientid);
    xsmp.clientid = NULL;
    xsmp_icefd = -1;
}
#endif // USE_XSMP

#if defined(FEAT_RELTIME) || defined(PROTO)
# if defined(PROF_NSEC) || defined(PROTO)
/*
 * Implement timeout with timer_create() and timer_settime().
 */
static volatile sig_atomic_t timeout_flag = FALSE;
static timer_t		     timer_id;
static int		     timer_created = FALSE;

/*
 * Callback for when the timer expires.
 */
    static void
set_flag(union sigval _unused UNUSED)
{
    timeout_flag = TRUE;
}

/*
 * Stop any active timeout.
 */
    void
stop_timeout(void)
{
    static struct itimerspec disarm = {{0, 0}, {0, 0}};

    if (timer_created)
    {
	int ret = timer_settime(timer_id, 0, &disarm, NULL);

	if (ret < 0)
	    semsg(_(e_could_not_clear_timeout_str), strerror(errno));
    }

    // Clear the current timeout flag; any previous timeout should be
    // considered _not_ triggered.
    timeout_flag = FALSE;
}

/*
 * Start the timeout timer.
 *
 * The return value is a pointer to a flag that is initialised to FALSE. If the
 * timeout expires, the flag is set to TRUE. This will only return pointers to
 * static memory; i.e. any pointer returned by this function may always be
 * safely dereferenced.
 *
 * This function is not expected to fail, but if it does it will still return a
 * valid flag pointer; the flag will remain stuck as FALSE .
 */
    volatile sig_atomic_t *
start_timeout(long msec)
{
    struct itimerspec interval = {
	    {0, 0},					// Do not repeat.
	    {msec / 1000, (msec % 1000) * 1000000}};	// Timeout interval
    int ret;

    // This is really the caller's responsibility, but let's make sure the
    // previous timer has been stopped.
    stop_timeout();

    if (!timer_created)
    {
	struct sigevent action = {0};

	action.sigev_notify = SIGEV_THREAD;
	action.sigev_notify_function = set_flag;
	ret = timer_create(CLOCK_MONOTONIC, &action, &timer_id);
	if (ret < 0)
	{
	    semsg(_(e_could_not_set_timeout_str), strerror(errno));
	    return &timeout_flag;
	}
	timer_created = TRUE;
    }

# ifdef FEAT_EVAL
    ch_log(NULL, "setting timeout timer to %d sec %ld nsec",
	       (int)interval.it_value.tv_sec, (long)interval.it_value.tv_nsec);
# endif
    ret = timer_settime(timer_id, 0, &interval, NULL);
    if (ret < 0)
	semsg(_(e_could_not_set_timeout_str), strerror(errno));

    return &timeout_flag;
}

/*
 * To be used before fork/exec: delete any created timer.
 */
    void
delete_timer(void)
{
    if (!timer_created)
	return;

    timer_delete(timer_id);
    timer_created = FALSE;
}

# else // PROF_NSEC

/*
 * Implement timeout with setitimer()
 */
static struct sigaction		prev_sigaction;
static volatile sig_atomic_t	timeout_flag	     = FALSE;
static int			timer_active	     = FALSE;
static int			timer_handler_active = FALSE;
static volatile sig_atomic_t	alarm_pending	     = FALSE;

/*
 * Handle SIGALRM for a timeout.
 */
    static void
set_flag SIGDEFARG(sigarg)
{
    if (alarm_pending)
	alarm_pending = FALSE;
    else
	timeout_flag = TRUE;
}

/*
 * Stop any active timeout.
 */
    void
stop_timeout(void)
{
    static struct itimerval disarm = {{0, 0}, {0, 0}};
    int			    ret;

    if (timer_active)
    {
	timer_active = FALSE;
	ret = setitimer(ITIMER_REAL, &disarm, NULL);
	if (ret < 0)
	    // Should only get here as a result of coding errors.
	    semsg(_(e_could_not_clear_timeout_str), strerror(errno));
    }

    if (timer_handler_active)
    {
	timer_handler_active = FALSE;
	ret = sigaction(SIGALRM, &prev_sigaction, NULL);
	if (ret < 0)
	    // Should only get here as a result of coding errors.
	    semsg(_(e_could_not_reset_handler_for_timeout_str),
							      strerror(errno));
    }
    timeout_flag = FALSE;
}

/*
 * Start the timeout timer.
 *
 * The return value is a pointer to a flag that is initialised to FALSE. If the
 * timeout expires, the flag is set to TRUE. This will only return pointers to
 * static memory; i.e. any pointer returned by this function may always be
 * safely dereferenced.
 *
 * This function is not expected to fail, but if it does it will still return a
 * valid flag pointer; the flag will remain stuck as FALSE .
 */
    volatile sig_atomic_t *
start_timeout(long msec)
{
    struct itimerval	interval = {
	    {0, 0},				    // Do not repeat.
	    {msec / 1000, (msec % 1000) * 1000}};   // Timeout interval
    struct sigaction	handle_alarm;
    int			ret;
    sigset_t		sigs;
    sigset_t		saved_sigs;

    // This is really the caller's responsibility, but let's make sure the
    // previous timer has been stopped.
    stop_timeout();

    // There is a small chance that SIGALRM is pending and so the handler must
    // ignore it on the first call.
    alarm_pending = FALSE;
    ret = sigemptyset(&sigs);
    ret = ret == 0 ? sigaddset(&sigs, SIGALRM) : ret;
    ret = ret == 0 ? sigprocmask(SIG_BLOCK, &sigs, &saved_sigs) : ret;
    timeout_flag = FALSE;
    ret = ret == 0 ? sigpending(&sigs) : ret;
    if (ret == 0)
    {
	alarm_pending = sigismember(&sigs, SIGALRM);
	ret = sigprocmask(SIG_SETMASK, &saved_sigs, NULL);
    }
    if (unlikely(ret != 0 || alarm_pending < 0))
    {
	// Just catching coding errors. Write an error message, but carry on.
	semsg(_(e_could_not_check_for_pending_sigalrm_str), strerror(errno));
	alarm_pending = FALSE;
    }

    // Set up the alarm handler first.
    ret = sigemptyset(&handle_alarm.sa_mask);
    handle_alarm.sa_handler = set_flag;
    handle_alarm.sa_flags = 0;
    ret = ret == 0 ?  sigaction(SIGALRM, &handle_alarm, &prev_sigaction) : ret;
    if (ret < 0)
    {
	// Should only get here as a result of coding errors.
	semsg(_(e_could_not_set_handler_for_timeout_str), strerror(errno));
	return &timeout_flag;
    }
    timer_handler_active = TRUE;

    // Set up the interval timer once the alarm handler is in place.
    ret = setitimer(ITIMER_REAL, &interval, NULL);
    if (ret < 0)
    {
	// Should only get here as a result of coding errors.
	semsg(_(e_could_not_set_timeout_str), strerror(errno));
	stop_timeout();
	return &timeout_flag;
    }

    timer_active = TRUE;
    return &timeout_flag;
}
# endif // PROF_NSEC
#endif  // FEAT_RELTIME