patch 8.0.1832: cannot use :unlet for an environment variable commit https://github.com/vim/vim/commit/137374fd6538cf9dee0cb22907728d8fdecb5832 Author: Bram Moolenaar <Bram@vim.org> Date: Sun May 13 15:59:50 2018 +0200 patch 8.0.1832: cannot use :unlet for an environment variable Problem: Cannot use :unlet for an environment variable. Solution: Make it work. Use unsetenv() if available. (Ken Takata, closes #2855)

/* if_tcl.c */
void vim_tcl_init(char *arg);
int tcl_enabled(int verbose);
void tcl_end(void);
void ex_tcl(exarg_T *eap);
void ex_tclfile(exarg_T *eap);
void ex_tcldo(exarg_T *eap);
void tcl_buffer_free(buf_T *buf);
void tcl_window_free(win_T *win);
/* vim: set ft=c : */