Mercurial > vim
annotate runtime/doc/usr_30.txt @ 6260:74c65620c985 v7.4.464
updated for version 7.4.464
Problem: Compiler warning.
Solution: Add type cast. (Ken Takata)
| author | Bram Moolenaar <bram@vim.org> |
|---|---|
| date | Mon, 06 Oct 2014 18:10:09 +0200 |
| parents | 40f18a1c1592 |
| children | 9f48eab77d62 |
| rev | line source |
|---|---|
| 5294 | 1 *usr_30.txt* For Vim version 7.4. Last change: 2007 Nov 10 |
| 7 | 2 |
| 3 VIM USER MANUAL - by Bram Moolenaar | |
| 4 | |
| 5 Editing programs | |
| 6 | |
| 7 | |
| 8 Vim has various commands that aid in writing computer programs. Compile a | |
| 9 program and directly jump to reported errors. Automatically set the indent | |
| 10 for many languages and format comments. | |
| 11 | |
| 12 |30.1| Compiling | |
| 13 |30.2| Indenting C files | |
| 14 |30.3| Automatic indenting | |
| 15 |30.4| Other indenting | |
| 16 |30.5| Tabs and spaces | |
| 17 |30.6| Formatting comments | |
| 18 | |
| 19 Next chapter: |usr_31.txt| Exploiting the GUI | |
| 20 Previous chapter: |usr_29.txt| Moving through programs | |
| 21 Table of contents: |usr_toc.txt| | |
| 22 | |
| 23 ============================================================================== | |
| 24 *30.1* Compiling | |
| 25 | |
| 26 Vim has a set of so called "quickfix" commands. They enable you to compile a | |
| 27 program from within Vim and then go through the errors generated and fix them | |
| 28 (hopefully). You can then recompile and fix any new errors that are found | |
| 29 until finally your program compiles without any error. | |
| 30 | |
| 31 The following command runs the program "make" (supplying it with any argument | |
| 32 you give) and captures the results: > | |
| 33 | |
| 34 :make {arguments} | |
| 35 | |
| 36 If errors were generated, they are captured and the editor positions you where | |
| 37 the first error occurred. | |
| 237 | 38 Take a look at an example ":make" session. (Typical :make sessions generate |
| 7 | 39 far more errors and fewer stupid ones.) After typing ":make" the screen looks |
| 40 like this: | |
| 41 | |
| 42 :!make | &tee /tmp/vim215953.err ~ | |
| 43 gcc -g -Wall -o prog main.c sub.c ~ | |
| 44 main.c: In function 'main': ~ | |
| 45 main.c:6: too many arguments to function 'do_sub' ~ | |
| 46 main.c: At top level: ~ | |
| 47 main.c:10: parse error before '}' ~ | |
| 48 make: *** [prog] Error 1 ~ | |
| 49 | |
| 50 2 returned ~ | |
| 51 "main.c" 11L, 111C ~ | |
| 52 (3 of 6): too many arguments to function 'do_sub' ~ | |
| 1125 | 53 Press ENTER or type command to continue ~ |
| 7 | 54 |
| 55 From this you can see that you have errors in the file "main.c". When you | |
| 56 press <Enter>, Vim displays the file "main.c", with the cursor positioned on | |
| 57 line 6, the first line with an error. You did not need to specify the file or | |
| 58 the line number, Vim knew where to go by looking in the error messages. | |
| 59 | |
| 60 +---------------------------------------------------+ | |
| 61 |int main() | | |
| 62 |{ | | |
| 63 | int i=3; | | |
| 64 cursor -> | do_sub("foo"); | | |
| 65 | ++i; | | |
| 66 | return (0); | | |
| 67 |} | | |
| 68 |} | | |
| 69 | ~ | | |
| 70 |(3 of 12): too many arguments to function 'do_sub' | | |
| 71 +---------------------------------------------------+ | |
| 72 | |
| 73 The following command goes to where the next error occurs: > | |
| 74 | |
| 75 :cnext | |
| 76 | |
| 77 Vim jumps to line 10, the last line in the file, where there is an extra '}'. | |
| 78 When there is not enough room, Vim will shorten the error message. To see | |
| 79 the whole message use: > | |
| 80 | |
| 81 :cc | |
| 82 | |
| 83 You can get an overview of all the error messages with the ":clist" command. | |
| 84 The output looks like this: > | |
| 85 | |
| 86 :clist | |
| 87 < 3 main.c: 6:too many arguments to function 'do_sub' ~ | |
| 88 5 main.c: 10:parse error before '}' ~ | |
| 89 | |
| 90 Only the lines where Vim recognized a file name and line number are listed | |
| 91 here. It assumes those are the interesting lines and the rest is just boring | |
| 92 messages. However, sometimes unrecognized lines do contain something you want | |
| 93 to see. Output from the linker, for example, about an undefined function. | |
| 94 To see all the messages add a "!" to the command: > | |
| 95 | |
| 96 :clist! | |
| 97 < 1 gcc -g -Wall -o prog main.c sub.c ~ | |
| 98 2 main.c: In function 'main': ~ | |
| 99 3 main.c:6: too many arguments to function 'do_sub' ~ | |
| 100 4 main.c: At top level: ~ | |
| 101 5 main.c:10: parse error before '}' ~ | |
| 102 6 make: *** [prog] Error 1 ~ | |
| 103 | |
| 104 Vim will highlight the current error. To go back to the previous error, use: | |
| 105 > | |
| 106 :cprevious | |
| 107 | |
| 108 Other commands to move around in the error list: | |
| 109 | |
| 110 :cfirst to first error | |
| 111 :clast to last error | |
| 112 :cc 3 to error nr 3 | |
| 113 | |
| 114 | |
| 115 USING ANOTHER COMPILER | |
| 116 | |
| 117 The name of the program to run when the ":make" command is executed is defined | |
| 118 by the 'makeprg' option. Usually this is set to "make", but Visual C++ users | |
| 119 should set this to "nmake" by executing the following command: > | |
| 120 | |
| 121 :set makeprg=nmake | |
| 122 | |
| 123 You can also include arguments in this option. Special characters need to | |
| 124 be escaped with a backslash. Example: > | |
| 125 | |
| 126 :set makeprg=nmake\ -f\ project.mak | |
| 127 | |
| 128 You can include special Vim keywords in the command specification. The % | |
| 129 character expands to the name of the current file. So if you execute the | |
| 130 command: > | |
| 5690 | 131 :set makeprg=make\ %:S |
| 7 | 132 |
| 133 When you are editing main.c, then ":make" executes the following command: > | |
| 134 | |
| 135 make main.c | |
| 136 | |
| 137 This is not too useful, so you will refine the command a little and use the :r | |
| 138 (root) modifier: > | |
| 139 | |
| 5690 | 140 :set makeprg=make\ %:r:S.o |
| 7 | 141 |
| 142 Now the command executed is as follows: > | |
| 143 | |
| 144 make main.o | |
| 145 | |
| 146 More about these modifiers here: |filename-modifiers|. | |
| 147 | |
| 148 | |
| 149 OLD ERROR LISTS | |
| 150 | |
| 1125 | 151 Suppose you ":make" a program. There is a warning message in one file and an |
| 7 | 152 error message in another. You fix the error and use ":make" again to check if |
| 153 it was really fixed. Now you want to look at the warning message. It doesn't | |
| 154 show up in the last error list, since the file with the warning wasn't | |
| 155 compiled again. You can go back to the previous error list with: > | |
| 156 | |
| 157 :colder | |
| 158 | |
| 159 Then use ":clist" and ":cc {nr}" to jump to the place with the warning. | |
| 160 To go forward to the next error list: > | |
| 161 | |
| 162 :cnewer | |
| 163 | |
| 164 Vim remembers ten error lists. | |
| 165 | |
| 166 | |
| 167 SWITCHING COMPILERS | |
| 168 | |
| 169 You have to tell Vim what format the error messages are that your compiler | |
| 170 produces. This is done with the 'errorformat' option. The syntax of this | |
| 171 option is quite complicated and it can be made to fit almost any compiler. | |
| 172 You can find the explanation here: |errorformat|. | |
| 173 | |
| 174 You might be using various different compilers. Setting the 'makeprg' option, | |
| 175 and especially the 'errorformat' each time is not easy. Vim offers a simple | |
| 176 method for this. For example, to switch to using the Microsoft Visual C++ | |
| 177 compiler: > | |
| 178 | |
| 179 :compiler msvc | |
| 180 | |
| 181 This will find the Vim script for the "msvc" compiler and set the appropriate | |
| 182 options. | |
| 183 You can write your own compiler files. See |write-compiler-plugin|. | |
| 184 | |
| 185 | |
| 186 OUTPUT REDIRECTION | |
| 187 | |
| 188 The ":make" command redirects the output of the executed program to an error | |
| 189 file. How this works depends on various things, such as the 'shell'. If your | |
| 190 ":make" command doesn't capture the output, check the 'makeef' and | |
| 191 'shellpipe' options. The 'shellquote' and 'shellxquote' options might also | |
| 192 matter. | |
| 193 | |
| 194 In case you can't get ":make" to redirect the file for you, an alternative is | |
| 195 to compile the program in another window and redirect the output into a file. | |
| 196 Then have Vim read this file with: > | |
| 197 | |
| 198 :cfile {filename} | |
| 199 | |
| 200 Jumping to errors will work like with the ":make" command. | |
| 201 | |
| 202 ============================================================================== | |
| 1624 | 203 *30.2* Indenting C style text |
| 7 | 204 |
| 205 A program is much easier to understand when the lines have been properly | |
| 1624 | 206 indented. Vim offers various ways to make this less work. For C or C style |
| 207 programs like Java or C++, set the 'cindent' option. Vim knows a lot about C | |
| 208 programs and will try very hard to automatically set the indent for you. Set | |
| 209 the 'shiftwidth' option to the amount of spaces you want for a deeper level. | |
| 210 Four spaces will work fine. One ":set" command will do it: > | |
| 7 | 211 |
| 212 :set cindent shiftwidth=4 | |
| 213 | |
| 214 With this option enabled, when you type something such as "if (x)", the next | |
| 215 line will automatically be indented an additional level. | |
| 216 | |
| 217 if (flag) | |
| 218 Automatic indent ---> do_the_work(); | |
| 219 Automatic unindent <-- if (other_flag) { | |
| 220 Automatic indent ---> do_file(); | |
| 221 keep indent do_some_more(); | |
| 222 Automatic unindent <-- } | |
| 223 | |
| 224 When you type something in curly braces ({}), the text will be indented at the | |
| 225 start and unindented at the end. The unindenting will happen after typing the | |
| 226 '}', since Vim can't guess what you are going to type. | |
| 227 | |
| 228 One side effect of automatic indentation is that it helps you catch errors in | |
| 229 your code early. When you type a } to finish a function, only to find that | |
| 230 the automatic indentation gives it more indent than what you expected, there | |
| 231 is probably a } missing. Use the "%" command to find out which { matches the | |
| 232 } you typed. | |
| 233 A missing ) and ; also cause extra indent. Thus if you get more white | |
| 234 space than you would expect, check the preceding lines. | |
| 235 | |
| 236 When you have code that is badly formatted, or you inserted and deleted lines, | |
| 237 you need to re-indent the lines. The "=" operator does this. The simplest | |
| 238 form is: > | |
| 239 | |
| 240 == | |
| 241 | |
| 242 This indents the current line. Like with all operators, there are three ways | |
| 243 to use it. In Visual mode "=" indents the selected lines. A useful text | |
| 244 object is "a{". This selects the current {} block. Thus, to re-indent the | |
| 1125 | 245 code block the cursor is in: > |
| 7 | 246 |
| 247 =a{ | |
| 248 | |
| 249 I you have really badly indented code, you can re-indent the whole file with: | |
| 250 > | |
| 251 gg=G | |
| 252 | |
| 253 However, don't do this in files that have been carefully indented manually. | |
| 254 The automatic indenting does a good job, but in some situations you might want | |
| 255 to overrule it. | |
| 256 | |
| 257 | |
| 258 SETTING INDENT STYLE | |
| 259 | |
| 260 Different people have different styles of indentation. By default Vim does a | |
| 261 pretty good job of indenting in a way that 90% of programmers do. There are | |
| 262 different styles, however; so if you want to, you can customize the | |
| 263 indentation style with the 'cinoptions' option. | |
| 264 By default 'cinoptions' is empty and Vim uses the default style. You can | |
| 265 add various items where you want something different. For example, to make | |
| 266 curly braces be placed like this: | |
| 267 | |
| 268 if (flag) ~ | |
| 269 { ~ | |
| 270 i = 8; ~ | |
| 271 j = 0; ~ | |
| 272 } ~ | |
| 273 | |
| 274 Use this command: > | |
| 275 | |
| 276 :set cinoptions+={2 | |
| 277 | |
| 278 There are many of these items. See |cinoptions-values|. | |
| 279 | |
| 280 ============================================================================== | |
| 281 *30.3* Automatic indenting | |
| 282 | |
| 283 You don't want to switch on the 'cindent' option manually every time you edit | |
| 284 a C file. This is how you make it work automatically: > | |
| 285 | |
| 286 :filetype indent on | |
| 287 | |
| 288 Actually, this does a lot more than switching on 'cindent' for C files. First | |
| 289 of all, it enables detecting the type of a file. That's the same as what is | |
| 290 used for syntax highlighting. | |
| 291 When the filetype is known, Vim will search for an indent file for this | |
| 292 type of file. The Vim distribution includes a number of these for various | |
| 293 programming languages. This indent file will then prepare for automatic | |
| 294 indenting specifically for this file. | |
| 295 | |
| 296 If you don't like the automatic indenting, you can switch it off again: > | |
| 297 | |
| 298 :filetype indent off | |
| 299 | |
| 300 If you don't like the indenting for one specific type of file, this is how you | |
| 301 avoid it. Create a file with just this one line: > | |
| 302 | |
| 303 :let b:did_indent = 1 | |
| 304 | |
| 305 Now you need to write this in a file with a specific name: | |
| 306 | |
| 307 {directory}/indent/{filetype}.vim | |
| 308 | |
| 309 The {filetype} is the name of the file type, such as "cpp" or "java". You can | |
| 310 see the exact name that Vim detected with this command: > | |
| 311 | |
| 312 :set filetype | |
| 313 | |
| 314 In this file the output is: | |
| 315 | |
| 316 filetype=help ~ | |
| 317 | |
| 1125 | 318 Thus you would use "help" for {filetype}. |
| 7 | 319 For the {directory} part you need to use your runtime directory. Look at |
| 320 the output of this command: > | |
| 321 | |
| 322 set runtimepath | |
| 323 | |
| 324 Now use the first item, the name before the first comma. Thus if the output | |
| 325 looks like this: | |
| 326 | |
| 327 runtimepath=~/.vim,/usr/local/share/vim/vim60/runtime,~/.vim/after ~ | |
| 328 | |
| 329 You use "~/.vim" for {directory}. Then the resulting file name is: | |
| 330 | |
| 331 ~/.vim/indent/help.vim ~ | |
| 332 | |
| 333 Instead of switching the indenting off, you could write your own indent file. | |
| 334 How to do that is explained here: |indent-expression|. | |
| 335 | |
| 336 ============================================================================== | |
| 337 *30.4* Other indenting | |
| 338 | |
| 339 The most simple form of automatic indenting is with the 'autoindent' option. | |
| 340 It uses the indent from the previous line. A bit smarter is the 'smartindent' | |
| 341 option. This is useful for languages where no indent file is available. | |
| 1125 | 342 'smartindent' is not as smart as 'cindent', but smarter than 'autoindent'. |
| 7 | 343 With 'smartindent' set, an extra level of indentation is added for each { |
| 344 and removed for each }. An extra level of indentation will also be added for | |
| 345 any of the words in the 'cinwords' option. Lines that begin with # are | |
| 346 treated specially: all indentation is removed. This is done so that | |
| 347 preprocessor directives will all start in column 1. The indentation is | |
| 348 restored for the next line. | |
| 349 | |
| 350 | |
| 351 CORRECTING INDENTS | |
| 352 | |
| 353 When you are using 'autoindent' or 'smartindent' to get the indent of the | |
| 354 previous line, there will be many times when you need to add or remove one | |
| 355 'shiftwidth' worth of indent. A quick way to do this is using the CTRL-D and | |
| 356 CTRL-T commands in Insert mode. | |
| 357 For example, you are typing a shell script that is supposed to look like | |
| 358 this: | |
| 359 | |
| 360 if test -n a; then ~ | |
| 361 echo a ~ | |
| 362 echo "-------" ~ | |
| 363 fi ~ | |
| 364 | |
|
2207
b17bbfa96fa0
Add the settabvar() and gettabvar() functions.
Bram Moolenaar <bram@vim.org>
parents:
2154
diff
changeset
|
365 Start off by setting these options: > |
| 7 | 366 |
| 367 :set autoindent shiftwidth=3 | |
| 368 | |
| 369 You start by typing the first line, <Enter> and the start of the second line: | |
| 370 | |
| 371 if test -n a; then ~ | |
| 372 echo ~ | |
| 373 | |
| 374 Now you see that you need an extra indent. Type CTRL-T. The result: | |
| 375 | |
| 376 if test -n a; then ~ | |
| 377 echo ~ | |
| 378 | |
| 379 The CTRL-T command, in Insert mode, adds one 'shiftwidth' to the indent, no | |
| 380 matter where in the line you are. | |
| 381 You continue typing the second line, <Enter> and the third line. This time | |
| 382 the indent is OK. Then <Enter> and the last line. Now you have this: | |
| 383 | |
| 384 if test -n a; then ~ | |
| 385 echo a ~ | |
| 386 echo "-------" ~ | |
| 387 fi ~ | |
| 388 | |
| 389 To remove the superfluous indent in the last line press CTRL-D. This deletes | |
| 390 one 'shiftwidth' worth of indent, no matter where you are in the line. | |
| 391 When you are in Normal mode, you can use the ">>" and "<<" commands to | |
| 392 shift lines. ">" and "<" are operators, thus you have the usual three ways to | |
| 393 specify the lines you want to indent. A useful combination is: > | |
| 394 | |
| 395 >i{ | |
| 396 | |
| 397 This adds one indent to the current block of lines, inside {}. The { and } | |
| 398 lines themselves are left unmodified. ">a{" includes them. In this example | |
| 399 the cursor is on "printf": | |
| 400 | |
| 401 original text after ">i{" after ">a{" | |
| 402 | |
| 403 if (flag) if (flag) if (flag) ~ | |
| 404 { { { ~ | |
| 405 printf("yes"); printf("yes"); printf("yes"); ~ | |
| 406 flag = 0; flag = 0; flag = 0; ~ | |
| 407 } } } ~ | |
| 408 | |
| 409 ============================================================================== | |
| 410 *30.5* Tabs and spaces | |
| 411 | |
| 412 'tabstop' is set to eight by default. Although you can change it, you quickly | |
| 413 run into trouble later. Other programs won't know what tabstop value you | |
| 414 used. They probably use the default value of eight, and your text suddenly | |
| 415 looks very different. Also, most printers use a fixed tabstop value of eight. | |
| 416 Thus it's best to keep 'tabstop' alone. (If you edit a file which was written | |
| 417 with a different tabstop setting, see |25.3| for how to fix that.) | |
| 418 For indenting lines in a program, using a multiple of eight spaces makes | |
| 419 you quickly run into the right border of the window. Using a single space | |
| 420 doesn't provide enough visual difference. Many people prefer to use four | |
| 421 spaces, a good compromise. | |
| 422 Since a <Tab> is eight spaces and you want to use an indent of four spaces, | |
| 423 you can't use a <Tab> character to make your indent. There are two ways to | |
| 424 handle this: | |
| 425 | |
| 426 1. Use a mix of <Tab> and space characters. Since a <Tab> takes the place of | |
| 427 eight spaces, you have fewer characters in your file. Inserting a <Tab> | |
| 428 is quicker than eight spaces. Backspacing works faster as well. | |
| 429 | |
| 430 2. Use spaces only. This avoids the trouble with programs that use a | |
| 431 different tabstop value. | |
| 432 | |
| 433 Fortunately, Vim supports both methods quite well. | |
| 434 | |
| 435 | |
| 436 SPACES AND TABS | |
| 437 | |
| 438 If you are using a combination of tabs and spaces, you just edit normally. | |
| 439 The Vim defaults do a fine job of handling things. | |
| 440 You can make life a little easier by setting the 'softtabstop' option. | |
| 441 This option tells Vim to make the <Tab> key look and feel as if tabs were set | |
| 442 at the value of 'softtabstop', but actually use a combination of tabs and | |
| 443 spaces. | |
| 444 After you execute the following command, every time you press the <Tab> key | |
| 445 the cursor moves to the next 4-column boundary: > | |
| 446 | |
| 447 :set softtabstop=4 | |
| 448 | |
| 449 When you start in the first column and press <Tab>, you get 4 spaces inserted | |
| 450 in your text. The second time, Vim takes out the 4 spaces and puts in a <Tab> | |
| 451 (thus taking you to column 8). Thus Vim uses as many <Tab>s as possible, and | |
| 452 then fills up with spaces. | |
| 453 When backspacing it works the other way around. A <BS> will always delete | |
| 1624 | 454 the amount specified with 'softtabstop'. Then <Tab>s are used as many as |
| 7 | 455 possible and spaces to fill the gap. |
| 456 The following shows what happens pressing <Tab> a few times, and then using | |
| 457 <BS>. A "." stands for a space and "------->" for a <Tab>. | |
| 458 | |
| 459 type result ~ | |
| 460 <Tab> .... | |
| 461 <Tab><Tab> -------> | |
| 462 <Tab><Tab><Tab> ------->.... | |
| 463 <Tab><Tab><Tab><BS> -------> | |
| 464 <Tab><Tab><Tab><BS><BS> .... | |
| 465 | |
| 466 An alternative is to use the 'smarttab' option. When it's set, Vim uses | |
| 467 'shiftwidth' for a <Tab> typed in the indent of a line, and a real <Tab> when | |
| 468 typed after the first non-blank character. However, <BS> doesn't work like | |
| 469 with 'softtabstop'. | |
| 470 | |
| 471 | |
| 472 JUST SPACES | |
| 473 | |
| 474 If you want absolutely no tabs in your file, you can set the 'expandtab' | |
| 475 option: > | |
| 476 | |
| 477 :set expandtab | |
| 478 | |
| 479 When this option is set, the <Tab> key inserts a series of spaces. Thus you | |
| 480 get the same amount of white space as if a <Tab> character was inserted, but | |
| 481 there isn't a real <Tab> character in your file. | |
| 482 The backspace key will delete each space by itself. Thus after typing one | |
| 483 <Tab> you have to press the <BS> key up to eight times to undo it. If you are | |
| 484 in the indent, pressing CTRL-D will be a lot quicker. | |
| 485 | |
| 486 | |
| 487 CHANGING TABS IN SPACES (AND BACK) | |
| 488 | |
| 489 Setting 'expandtab' does not affect any existing tabs. In other words, any | |
| 490 tabs in the document remain tabs. If you want to convert tabs to spaces, use | |
| 491 the ":retab" command. Use these commands: > | |
| 492 | |
| 493 :set expandtab | |
| 494 :%retab | |
| 495 | |
| 496 Now Vim will have changed all indents to use spaces instead of tabs. However, | |
| 497 all tabs that come after a non-blank character are kept. If you want these to | |
| 498 be converted as well, add a !: > | |
| 499 | |
| 500 :%retab! | |
| 501 | |
| 502 This is a little bit dangerous, because it can also change tabs inside a | |
| 503 string. To check if these exist, you could use this: > | |
| 504 | |
| 505 /"[^"\t]*\t[^"]*" | |
| 506 | |
| 507 It's recommended not to use hard tabs inside a string. Replace them with | |
| 508 "\t" to avoid trouble. | |
| 509 | |
| 510 The other way around works just as well: > | |
| 511 | |
| 512 :set noexpandtab | |
| 513 :%retab! | |
| 514 | |
| 515 ============================================================================== | |
| 516 *30.6* Formatting comments | |
| 517 | |
| 518 One of the great things about Vim is that it understands comments. You can | |
| 519 ask Vim to format a comment and it will do the right thing. | |
| 520 Suppose, for example, that you have the following comment: | |
| 521 | |
| 522 /* ~ | |
| 523 * This is a test ~ | |
| 524 * of the text formatting. ~ | |
| 525 */ ~ | |
| 526 | |
| 527 You then ask Vim to format it by positioning the cursor at the start of the | |
| 528 comment and type: > | |
| 529 | |
| 530 gq]/ | |
| 531 | |
| 532 "gq" is the operator to format text. "]/" is the motion that takes you to the | |
| 533 end of a comment. The result is: | |
| 534 | |
| 535 /* ~ | |
| 536 * This is a test of the text formatting. ~ | |
| 537 */ ~ | |
| 538 | |
| 539 Notice that Vim properly handled the beginning of each line. | |
| 540 An alternative is to select the text that is to be formatted in Visual mode | |
| 541 and type "gq". | |
| 542 | |
| 543 To add a new line to the comment, position the cursor on the middle line and | |
| 544 press "o". The result looks like this: | |
| 545 | |
| 546 /* ~ | |
| 547 * This is a test of the text formatting. ~ | |
| 548 * ~ | |
| 549 */ ~ | |
| 550 | |
| 551 Vim has automatically inserted a star and a space for you. Now you can type | |
| 552 the comment text. When it gets longer than 'textwidth', Vim will break the | |
| 553 line. Again, the star is inserted automatically: | |
| 554 | |
| 555 /* ~ | |
| 556 * This is a test of the text formatting. ~ | |
| 557 * Typing a lot of text here will make Vim ~ | |
| 558 * break ~ | |
| 559 */ ~ | |
| 560 | |
| 561 For this to work some flags must be present in 'formatoptions': | |
| 562 | |
| 563 r insert the star when typing <Enter> in Insert mode | |
| 564 o insert the star when using "o" or "O" in Normal mode | |
| 565 c break comment text according to 'textwidth' | |
| 566 | |
| 567 See |fo-table| for more flags. | |
| 568 | |
| 569 | |
| 570 DEFINING A COMMENT | |
| 571 | |
| 572 The 'comments' option defines what a comment looks like. Vim distinguishes | |
| 573 between a single-line comment and a comment that has a different start, end | |
| 574 and middle part. | |
| 575 Many single-line comments start with a specific character. In C++ // is | |
| 576 used, in Makefiles #, in Vim scripts ". For example, to make Vim understand | |
| 577 C++ comments: > | |
| 578 | |
| 579 :set comments=:// | |
| 580 | |
| 581 The colon separates the flags of an item from the text by which the comment is | |
| 582 recognized. The general form of an item in 'comments' is: | |
| 583 | |
| 584 {flags}:{text} | |
| 585 | |
| 586 The {flags} part can be empty, as in this case. | |
| 587 Several of these items can be concatenated, separated by commas. This | |
| 588 allows recognizing different types of comments at the same time. For example, | |
| 589 let's edit an e-mail message. When replying, the text that others wrote is | |
| 590 preceded with ">" and "!" characters. This command would work: > | |
| 591 | |
| 592 :set comments=n:>,n:! | |
| 593 | |
| 594 There are two items, one for comments starting with ">" and one for comments | |
| 595 that start with "!". Both use the flag "n". This means that these comments | |
| 596 nest. Thus a line starting with ">" may have another comment after the ">". | |
| 597 This allows formatting a message like this: | |
| 598 | |
| 599 > ! Did you see that site? ~ | |
| 600 > ! It looks really great. ~ | |
| 601 > I don't like it. The ~ | |
| 602 > colors are terrible. ~ | |
| 603 What is the URL of that ~ | |
| 604 site? ~ | |
| 605 | |
| 606 Try setting 'textwidth' to a different value, e.g., 80, and format the text by | |
| 607 Visually selecting it and typing "gq". The result is: | |
| 608 | |
| 237 | 609 > ! Did you see that site? It looks really great. ~ |
| 7 | 610 > I don't like it. The colors are terrible. ~ |
| 611 What is the URL of that site? ~ | |
| 612 | |
| 613 You will notice that Vim did not move text from one type of comment to | |
| 614 another. The "I" in the second line would have fit at the end of the first | |
| 615 line, but since that line starts with "> !" and the second line with ">", Vim | |
| 616 knows that this is a different kind of comment. | |
| 617 | |
| 618 | |
| 619 A THREE PART COMMENT | |
| 620 | |
| 621 A C comment starts with "/*", has "*" in the middle and "*/" at the end. The | |
| 622 entry in 'comments' for this looks like this: > | |
| 623 | |
| 624 :set comments=s1:/*,mb:*,ex:*/ | |
| 625 | |
| 626 The start is defined with "s1:/*". The "s" indicates the start of a | |
| 627 three-piece comment. The colon separates the flags from the text by which the | |
| 628 comment is recognized: "/*". There is one flag: "1". This tells Vim that the | |
| 629 middle part has an offset of one space. | |
| 630 The middle part "mb:*" starts with "m", which indicates it is a middle | |
| 631 part. The "b" flag means that a blank must follow the text. Otherwise Vim | |
| 632 would consider text like "*pointer" also to be the middle of a comment. | |
| 633 The end part "ex:*/" has the "e" for identification. The "x" flag has a | |
| 634 special meaning. It means that after Vim automatically inserted a star, | |
| 635 typing / will remove the extra space. | |
| 636 | |
| 637 For more details see |format-comments|. | |
| 638 | |
| 639 ============================================================================== | |
| 640 | |
| 641 Next chapter: |usr_31.txt| Exploiting the GUI | |
| 642 | |
| 643 Copyright: see |manual-copyright| vim:tw=78:ts=8:ft=help:norl: |