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Bram Moolenaar8aff23a2005-08-19 20:40:30 +00001*pattern.txt* For Vim version 7.0aa. Last change: 2005 Aug 18
Bram Moolenaar071d4272004-06-13 20:20:40 +00002
3
4 VIM REFERENCE MANUAL by Bram Moolenaar
5
6
7Patterns and search commands *pattern-searches*
8
9The very basics can be found in section |03.9| of the user manual. A few more
10explanations are in chapter 27 |usr_27.txt|.
11
121. Search commands |search-commands|
132. The definition of a pattern |search-pattern|
143. Magic |/magic|
154. Overview of pattern items |pattern-overview|
165. Multi items |pattern-multi-items|
176. Ordinary atoms |pattern-atoms|
187. Ignoring case in a pattern |/ignorecase|
198. Compare with Perl patterns |perl-patterns|
209. Highlighting matches |match-highlight|
21
22==============================================================================
231. Search commands *search-commands* *E486*
24
25 */*
26/{pattern}[/]<CR> Search forward for the [count]'th occurrence of
27 {pattern} |exclusive|.
28
29/{pattern}/{offset}<CR> Search forward for the [count]'th occurrence of
30 {pattern} and go |{offset}| lines up or down.
31 |linewise|.
32
33 */<CR>*
34/<CR> Search forward for the [count]'th latest used
35 pattern |last-pattern| with latest used |{offset}|.
36
37//{offset}<CR> Search forward for the [count]'th latest used
38 pattern |last-pattern| with new |{offset}|. If
39 {offset} is empty no offset is used.
40
41 *?*
42?{pattern}[?]<CR> Search backward for the [count]'th previous
43 occurrence of {pattern} |exclusive|.
44
45?{pattern}?{offset}<CR> Search backward for the [count]'th previous
46 occurrence of {pattern} and go |{offset}| lines up or
47 down |linewise|.
48
49 *?<CR>*
50?<CR> Search backward for the [count]'th latest used
51 pattern |last-pattern| with latest used |{offset}|.
52
53??{offset}<CR> Search backward for the [count]'th latest used
54 pattern |last-pattern| with new |{offset}|. If
55 {offset} is empty no offset is used.
56
57 *n*
58n Repeat the latest "/" or "?" [count] times.
59 |last-pattern| {Vi: no count}
60
61 *N*
62N Repeat the latest "/" or "?" [count] times in
63 opposite direction. |last-pattern| {Vi: no count}
64
65 *star* *E348* *E349*
66* Search forward for the [count]'th occurrence of the
67 word nearest to the cursor. The word used for the
68 search is the first of:
69 1. the keyword under the cursor |'iskeyword'|
70 2. the first keyword after the cursor, in the
71 current line
72 3. the non-blank word under the cursor
73 4. the first non-blank word after the cursor,
74 in the current line
75 Only whole keywords are searched for, like with the
76 command "/\<keyword\>". |exclusive| {not in Vi}
77 'ignorecase' is used, 'smartcase' is not.
78
79 *#*
80# Same as "*", but search backward. The pound sign
81 (character 163) also works. If the "#" key works as
82 backspace, try using "stty erase <BS>" before starting
83 Vim (<BS> is CTRL-H or a real backspace). {not in Vi}
84
85 *gstar*
86g* Like "*", but don't put "\<" and "\>" around the word.
87 This makes the search also find matches that are not a
88 whole word. {not in Vi}
89
90 *g#*
91g# Like "#", but don't put "\<" and "\>" around the word.
92 This makes the search also find matches that are not a
93 whole word. {not in Vi}
94
95 *gd*
96gd Goto local Declaration. When the cursor is on a local
97 variable, this command will jump to its declaration.
98 First Vim searches for the start of the current
99 function, just like "[[". If it is not found the
100 search stops in line 1. If it is found, Vim goes back
101 until a blank line is found. From this position Vim
102 searches for the keyword under the cursor, like with
103 "*", but lines that look like a comment are ignored
104 (see 'comments' option).
105 Note that this is not guaranteed to work, Vim does not
106 really check the syntax, it only searches for a match
107 with the keyword. If included files also need to be
108 searched use the commands listed in |include-search|.
109 After this command |n| searches forward for the next
110 match (not backward).
111 {not in Vi}
112
113 *gD*
114gD Goto global Declaration. When the cursor is on a
115 global variable that is defined in the file, this
116 command will jump to its declaration. This works just
117 like "gd", except that the search for the keyword
118 always starts in line 1. {not in Vi}
119
120 *CTRL-C*
121CTRL-C Interrupt current (search) command. Use CTRL-Break on
122 MS-DOS |dos-CTRL-Break|.
123 In Normal mode, any pending command is aborted.
124
125 *:noh* *:nohlsearch*
126:noh[lsearch] Stop the highlighting for the 'hlsearch' option. It
127 is automatically turned back on when using a search
128 command, or setting the 'hlsearch' option.
129 This command doesn't work in an autocommand, because
130 the highlighting state is saved and restored when
131 executing autocommands |autocmd-searchpat|.
132
133While typing the search pattern the current match will be shown if the
134'incsearch' option is on. Remember that you still have to finish the search
135command with <CR> to actually position the cursor at the displayed match. Or
136use <Esc> to abandon the search.
137
138All matches for the last used search pattern will be highlighted if you set
139the 'hlsearch' option. This can be suspended with the |:nohlsearch| command.
140
141 *search-offset* *{offset}*
142These commands search for the specified pattern. With "/" and "?" an
143additional offset may be given. There are two types of offsets: line offsets
144and character offsets. {the character offsets are not in Vi}
145
146The offset gives the cursor position relative to the found match:
147 [num] [num] lines downwards, in column 1
148 +[num] [num] lines downwards, in column 1
149 -[num] [num] lines upwards, in column 1
150 e[+num] [num] characters to the right of the end of the match
151 e[-num] [num] characters to the left of the end of the match
152 s[+num] [num] characters to the right of the start of the match
153 s[-num] [num] characters to the left of the start of the match
154 b[+num] [num] identical to s[+num] above (mnemonic: begin)
155 b[-num] [num] identical to s[-num] above (mnemonic: begin)
Bram Moolenaar1cd871b2004-12-19 22:46:22 +0000156 ;{pattern} perform another searcn, see |//;|
Bram Moolenaar071d4272004-06-13 20:20:40 +0000157
158If a '-' or '+' is given but [num] is omitted, a count of one will be used.
159When including an offset with 'e', the search becomes inclusive (the
160character the cursor lands on is included in operations).
161
162Examples:
163
164pattern cursor position ~
165/test/+1 one line below "test", in column 1
166/test/e on the last t of "test"
167/test/s+2 on the 's' of "test"
168/test/b-3 three characters before "test"
169
170If one of these commands is used after an operator, the characters between
171the cursor position before and after the search is affected. However, if a
172line offset is given, the whole lines between the two cursor positions are
173affected.
174
175An example of how to search for matches with a pattern and change the match
176with another word: >
177 /foo<CR> find "foo"
178 c//e change until end of match
179 bar<Esc> type replacement
180 //<CR> go to start of next match
181 c//e change until end of match
182 beep<Esc> type another replacement
183 etc.
184<
185 *//;* *E386*
186A very special offset is ';' followed by another search command. For example: >
187
188 /test 1/;/test
189 /test.*/+1;?ing?
190
191The first one first finds the next occurrence of "test 1", and then the first
192occurrence of "test" after that.
193
194This is like executing two search commands after each other, except that:
195- It can be used as a single motion command after an operator.
196- The direction for a following "n" or "N" command comes from the first
197 search command.
198- When an error occurs the cursor is not moved at all.
199
200 *last-pattern*
201The last used pattern and offset are remembered. They can be used to repeat
202the search, possibly in another direction or with another count. Note that
203two patterns are remembered: One for 'normal' search commands and one for the
204substitute command ":s". Each time an empty pattern is given, the previously
205used pattern is used.
206
207The 'magic' option sticks with the last used pattern. If you change 'magic',
208this will not change how the last used pattern will be interpreted.
209The 'ignorecase' option does not do this. When 'ignorecase' is changed, it
210will result in the pattern to match other text.
211
212All matches for the last used search pattern will be highlighted if you set
213the 'hlsearch' option.
214
215To clear the last used search pattern: >
216 :let @/ = ""
217This will not set the pattern to an empty string, because that would match
218everywhere. The pattern is really cleared, like when starting Vim.
219
Bram Moolenaar8f999f12005-01-25 22:12:55 +0000220The search usually skips matches that don't move the cursor. Whether the next
Bram Moolenaar071d4272004-06-13 20:20:40 +0000221match is found at the next character or after the skipped match depends on the
222'c' flag in 'cpoptions'. See |cpo-c|.
223 with 'c' flag: "/..." advances 1 to 3 characters
224 without 'c' flag: "/..." advances 1 character
225The unpredictability with the 'c' flag is caused by starting the search in the
226first column, skipping matches until one is found past the cursor position.
227
Bram Moolenaar8f999f12005-01-25 22:12:55 +0000228When searching backwards, searching starts at the start of the line, using the
229'c' flag in 'cpoptions' as described above. Then the last match before the
230cursor position is used.
231
Bram Moolenaar071d4272004-06-13 20:20:40 +0000232In Vi the ":tag" command sets the last search pattern when the tag is searched
233for. In Vim this is not done, the previous search pattern is still remembered,
234unless the 't' flag is present in 'cpoptions'. The search pattern is always
235put in the search history.
236
237If the 'wrapscan' option is on (which is the default), searches wrap around
238the end of the buffer. If 'wrapscan' is not set, the backward search stops
239at the beginning and the forward search stops at the end of the buffer. If
240'wrapscan' is set and the pattern was not found the error message "pattern
241not found" is given, and the cursor will not be moved. If 'wrapscan' is not
242set the message becomes "search hit BOTTOM without match" when searching
243forward, or "search hit TOP without match" when searching backward. If
244wrapscan is set and the search wraps around the end of the file the message
245"search hit TOP, continuing at BOTTOM" or "search hit BOTTOM, continuing at
246TOP" is given when searching backwards or forwards respectively. This can be
247switched off by setting the 's' flag in the 'shortmess' option. The highlight
248method 'w' is used for this message (default: standout).
249
250 *search-range*
251You cannot limit the search command "/" to a certain range of lines. A trick
252to do this anyway is to use the ":substitute" command with the 'c' flag.
253Example: >
254 :.,300s/Pattern//gc
255This command will search from the cursor position until line 300 for
256"Pattern". At the match, you will be asked to type a character. Type 'q' to
257stop at this match, type 'n' to find the next match.
258
259The "*", "#", "g*" and "g#" commands look for a word near the cursor in this
260order, the first one that is found is used:
261- The keyword currently under the cursor.
262- The first keyword to the right of the cursor, in the same line.
263- The WORD currently under the cursor.
264- The first WORD to the right of the cursor, in the same line.
265The keyword may only contain letters and characters in 'iskeyword'.
266The WORD may contain any non-blanks (<Tab>s and/or <Space>s).
267Note that if you type with ten fingers, the characters are easy to remember:
268the "#" is under your left hand middle finger (search to the left and up) and
269the "*" is under your right hand middle finger (search to the right and down).
270(this depends on your keyboard layout though).
271
272==============================================================================
2732. The definition of a pattern *search-pattern* *pattern* *[pattern]*
274 *regular-expression* *regexp* *Pattern*
Bram Moolenaarf1f8bc52005-03-07 23:20:08 +0000275 *E76* *E383* *E476*
Bram Moolenaar071d4272004-06-13 20:20:40 +0000276
277For starters, read chapter 27 of the user manual |usr_27.txt|.
278
279 */bar* */\bar* */pattern*
2801. A pattern is one or more branches, separated by "\|". It matches anything
281 that matches one of the branches. Example: "foo\|beep" matches "foo" and
282 matches "beep". If more than one branch matches, the first one is used.
283
284 pattern ::= branch
285 or branch \| branch
286 or branch \| branch \| branch
287 etc.
288
289 */branch* */\&*
2902. A branch is one or more concats, separated by "\&". It matches the last
291 concat, but only if all the preceding concats also match at the same
292 position. Examples:
293 "foobeep\&..." matches "foo" in "foobeep".
294 ".*Peter\&.*Bob" matches in a line containing both "Peter" and "Bob"
295
296 branch ::= concat
297 or concat \& concat
298 or concat \& concat \& concat
299 etc.
300
301 */concat*
3023. A concat is one or more pieces, concatenated. It matches a match for the
303 first piece, followed by a match for the second piece, etc. Example:
304 "f[0-9]b", first matches "f", then a digit and then "b".
305
306 concat ::= piece
307 or piece piece
308 or piece piece piece
309 etc.
310
311 */piece*
3124. A piece is an atom, possibly followed by a multi, an indication of how many
313 times the atom can be matched. Example: "a*" matches any sequence of "a"
314 characters: "", "a", "aa", etc. See |/multi|.
315
316 piece ::= atom
317 or atom multi
318
319 */atom*
3205. An atom can be one of a long list of items. Many atoms match one character
321 in the text. It is often an ordinary character or a character class.
322 Braces can be used to make a pattern into an atom. The "\z(\)" construct
323 is only for syntax highlighting.
324
325 atom ::= ordinary-atom |/ordinary-atom|
326 or \( pattern \) |/\(|
327 or \%( pattern \) |/\%(|
328 or \z( pattern \) |/\z(|
329
330
331==============================================================================
3324. Overview of pattern items *pattern-overview*
333
334Overview of multi items. */multi* *E61* *E62*
335More explanation and examples below, follow the links. *E64*
336
337 multi ~
338 'magic' 'nomagic' matches of the preceding atom ~
339|/star| * \* 0 or more as many as possible
340|/\+| \+ \+ 1 or more as many as possible (*)
341|/\=| \= \= 0 or 1 as many as possible (*)
342|/\?| \? \? 0 or 1 as many as possible (*)
343
344|/\{| \{n,m} \{n,m} n to m as many as possible (*)
345 \{n} \{n} n exactly (*)
346 \{n,} \{n,} at least n as many as possible (*)
347 \{,m} \{,m} 0 to m as many as possible (*)
348 \{} \{} 0 or more as many as possible (same as *) (*)
349
350|/\{-| \{-n,m} \{-n,m} n to m as few as possible (*)
351 \{-n} \{-n} n exactly (*)
352 \{-n,} \{-n,} at least n as few as possible (*)
353 \{-,m} \{-,m} 0 to m as few as possible (*)
354 \{-} \{-} 0 or more as few as possible (*)
355
356 *E59*
357|/\@>| \@> \@> 1, like matching a whole pattern (*)
358|/\@=| \@= \@= nothing, requires a match |/zero-width| (*)
359|/\@!| \@! \@! nothing, requires NO match |/zero-width| (*)
360|/\@<=| \@<= \@<= nothing, requires a match behind |/zero-width| (*)
361|/\@<!| \@<! \@<! nothing, requires NO match behind |/zero-width| (*)
362
363(*) {not in Vi}
364
365
366Overview of ordinary atoms. */ordinary-atom*
367More explanation and examples below, follow the links.
368
369 ordinary atom ~
370 magic nomagic matches ~
371|/^| ^ ^ start-of-line (at start of pattern) |/zero-width|
372|/\^| \^ \^ literal '^'
373|/\_^| \_^ \_^ start-of-line (used anywhere) |/zero-width|
374|/$| $ $ end-of-line (at end of pattern) |/zero-width|
375|/\$| \$ \$ literal '$'
376|/\_$| \_$ \_$ end-of-line (used anywhere) |/zero-width|
377|/.| . \. any single character (not an end-of-line)
378|/\_.| \_. \_. any single character or end-of-line
379|/\<| \< \< beginning of a word |/zero-width|
380|/\>| \> \> end of a word |/zero-width|
381|/\zs| \zs \zs anything, sets start of match
382|/\ze| \ze \ze anything, sets end of match
383|/\%^| \%^ \%^ beginning of file |/zero-width| *E71*
384|/\%$| \%$ \%$ end of file |/zero-width|
385|/\%#| \%# \%# cursor position |/zero-width|
386|/\%l| \%23l \%23l in line 23 |/zero-width|
387|/\%c| \%23c \%23c in column 23 |/zero-width|
388|/\%v| \%23v \%23v in virtual column 23 |/zero-width|
389
Bram Moolenaar5eb86f92004-07-26 12:53:41 +0000390Character classes {not in Vi}: */character-classes*
Bram Moolenaar071d4272004-06-13 20:20:40 +0000391|/\i| \i \i identifier character (see 'isident' option)
392|/\I| \I \I like "\i", but excluding digits
393|/\k| \k \k keyword character (see 'iskeyword' option)
394|/\K| \K \K like "\k", but excluding digits
395|/\f| \f \f file name character (see 'isfname' option)
396|/\F| \F \F like "\f", but excluding digits
397|/\p| \p \p printable character (see 'isprint' option)
398|/\P| \P \P like "\p", but excluding digits
399|/\s| \s \s whitespace character: <Space> and <Tab>
400|/\S| \S \S non-whitespace character; opposite of \s
401|/\d| \d \d digit: [0-9]
402|/\D| \D \D non-digit: [^0-9]
403|/\x| \x \x hex digit: [0-9A-Fa-f]
404|/\X| \X \X non-hex digit: [^0-9A-Fa-f]
405|/\o| \o \o octal digit: [0-7]
406|/\O| \O \O non-octal digit: [^0-7]
407|/\w| \w \w word character: [0-9A-Za-z_]
408|/\W| \W \W non-word character: [^0-9A-Za-z_]
409|/\h| \h \h head of word character: [A-Za-z_]
410|/\H| \H \H non-head of word character: [^A-Za-z_]
411|/\a| \a \a alphabetic character: [A-Za-z]
412|/\A| \A \A non-alphabetic character: [^A-Za-z]
413|/\l| \l \l lowercase character: [a-z]
414|/\L| \L \L non-lowercase character: [^a-z]
415|/\u| \u \u uppercase character: [A-Z]
416|/\U| \U \U non-uppercase character [^A-Z]
417|/\_| \_x \_x where x is any of the characters above: character
418 class with end-of-line included
419(end of character classes)
420
421|/\e| \e \e <Esc>
422|/\t| \t \t <Tab>
423|/\r| \r \r <CR>
424|/\b| \b \b <BS>
425|/\n| \n \n end-of-line
426|/~| ~ \~ last given substitute string
427|/\1| \1 \1 same string as matched by first \(\) {not in Vi}
428|/\2| \2 \2 Like "\1", but uses second \(\)
429 ...
430|/\9| \9 \9 Like "\1", but uses ninth \(\)
431 *E68*
432|/\z1| \z1 \z1 only for syntax highlighting, see |:syn-ext-match|
433 ...
434|/\z1| \z9 \z9 only for syntax highlighting, see |:syn-ext-match|
435
436 x x a character with no special meaning matches itself
437
438|/[]| [] \[] any character specified inside the []
Bram Moolenaarc0197e22004-09-13 20:26:32 +0000439|/\%[]| \%[] \%[] a sequence of optionally matched atoms
Bram Moolenaar071d4272004-06-13 20:20:40 +0000440
441|/\c| \c \c ignore case
442|/\C| \C \C match case
443|/\m| \m \m 'magic' on for the following chars in the pattern
444|/\M| \M \M 'magic' off for the following chars in the pattern
445|/\v| \v \v the following chars in the pattern are "very magic"
446|/\V| \V \V the following chars in the pattern are "very nomagic"
447|/\Z| \Z \Z ignore differences in Unicode "combining characters".
448 Useful when searching voweled Hebrew or Arabic text.
449
Bram Moolenaarc0197e22004-09-13 20:26:32 +0000450|/\%d| \%d \%d match specified decimal character (eg \%d123
451|/\%x| \%x \%x match specified hex character (eg \%x2a)
452|/\%o| \%o \%o match specified octal character (eg \%o040)
453|/\%u| \%u \%u match specified multibyte character (eg \%u20ac)
454|/\%U| \%U \%U match specified large multibyte character (eg
455 \%U12345678)
Bram Moolenaar071d4272004-06-13 20:20:40 +0000456
457Example matches ~
458\<\I\i* or
459\<\h\w*
460\<[a-zA-Z_][a-zA-Z0-9_]*
461 An identifier (e.g., in a C program).
462
463\(\.$\|\. \) A period followed by <EOL> or a space.
464
465[.!?][])"']*\($\|[ ]\) A search pattern that finds the end of a sentence,
466 with almost the same definition as the ")" command.
467
468cat\Z Both "cat" and "càt" ("a" followed by 0x0300)
469 Does not match "càt" (character 0x00e0), even
470 though it may look the same.
471
472
473==============================================================================
4743. Magic */magic*
475
476Some characters in the pattern are taken literally. They match with the same
477character in the text. When preceded with a backslash however, these
478characters get a special meaning.
479
480Other characters have a special meaning without a backslash. They need to be
481preceded with a backslash to match literally.
482
483If a character is taken literally or not depends on the 'magic' option and the
484items mentioned next.
485 */\m* */\M*
486Use of "\m" makes the pattern after it be interpreted as if 'magic' is set,
487ignoring the actual value of the 'magic' option.
488Use of "\M" makes the pattern after it be interpreted as if 'nomagic' is used.
489 */\v* */\V*
490Use of "\v" means that in the pattern after it all ASCII characters except
491'0'-'9', 'a'-'z', 'A'-'Z' and '_' have a special meaning. "very magic"
492
493Use of "\V" means that in the pattern after it only the backslash has a
494special meaning. "very nomagic"
495
496Examples:
497after: \v \m \M \V matches ~
498 'magic' 'nomagic'
499 $ $ $ \$ matches end-of-line
500 . . \. \. matches any character
501 * * \* \* any number of the previous atom
502 () \(\) \(\) \(\) grouping into an atom
503 | \| \| \| separating alternatives
504 \a \a \a \a alphabetic character
505 \\ \\ \\ \\ literal backslash
506 \. \. . . literal dot
507 \{ { { { literal '{'
508 a a a a literal 'a'
509
510{only Vim supports \m, \M, \v and \V}
511
512It is recommended to always keep the 'magic' option at the default setting,
513which is 'magic'. This avoids portability problems. To make a pattern immune
514to the 'magic' option being set or not, put "\m" or "\M" at the start of the
515pattern.
516
517
518==============================================================================
5195. Multi items *pattern-multi-items*
520
521An atom can be followed by an indication of how many times the atom can be
522matched and in what way. This is called a multi. See |/multi| for an
523overview.
524
Bram Moolenaar071d4272004-06-13 20:20:40 +0000525 */star* */\star* *E56*
526* (use \* when 'magic' is not set)
527 Matches 0 or more of the preceding atom, as many as possible.
528 Example 'nomagic' matches ~
529 a* a\* "", "a", "aa", "aaa", etc.
530 .* \.\* anything, also an empty string, no end-of-line
531 \_.* \_.\* everything up to the end of the buffer
532 \_.*END \_.\*END everything up to and including the last "END"
533 in the buffer
534
535 Exception: When "*" is used at the start of the pattern or just after
536 "^" it matches the star character.
537
538 Be aware that repeating "\_." can match a lot of text and take a long
539 time. For example, "\_.*END" matches all text from the current
540 position to the last occurrence of "END" in the file. Since the "*"
541 will match as many as possible, this first skips over all lines until
542 the end of the file and then tries matching "END", backing up one
543 character at a time.
544
545 */\+* *E57*
546\+ Matches 1 or more of the preceding atom, as many as possible. {not in
547 Vi}
548 Example matches ~
549 ^.\+$ any non-empty line
550 \s\+ white space of at least one character
551
552 */\=*
553\= Matches 0 or 1 of the preceding atom, as many as possible. {not in Vi}
554 Example matches ~
555 foo\= "fo" and "foo"
556
557 */\?*
558\? Just like \=. Cannot be used when searching backwards with the "?"
559 command. {not in Vi}
560
561 */\{* *E58* *E60* *E554*
562\{n,m} Matches n to m of the preceding atom, as many as possible
563\{n} Matches n of the preceding atom
564\{n,} Matches at least n of the preceding atom, as many as possible
565\{,m} Matches 0 to m of the preceding atom, as many as possible
566\{} Matches 0 or more of the preceding atom, as many as possible (like *)
567 */\{-*
568\{-n,m} matches n to m of the preceding atom, as few as possible
569\{-n} matches n of the preceding atom
570\{-n,} matches at least n of the preceding atom, as few as possible
571\{-,m} matches 0 to m of the preceding atom, as few as possible
572\{-} matches 0 or more of the preceding atom, as few as possible
573 {Vi does not have any of these}
574
Bram Moolenaar26a60b42005-02-22 08:49:11 +0000575 n and m are positive decimal numbers or zero
Bram Moolenaar071d4272004-06-13 20:20:40 +0000576
577 If a "-" appears immediately after the "{", then a shortest match
578 first algorithm is used (see example below). In particular, "\{-}" is
579 the same as "*" but uses the shortest match first algorithm. BUT: A
580 match that starts earlier is preferred over a shorter match: "a\{-}b"
581 matches "aaab" in "xaaab".
582
583 Example matches ~
584 ab\{2,3}c "abbc" or "abbbc"
585 a\{5} "aaaaa".
586 ab\{2,}c "abbc", "abbbc", "abbbbc", etc
587 ab\{,3}c "ac", "abc", "abbc" or "abbbc".
588 a[bc]\{3}d "abbbd", "abbcd", "acbcd", "acccd", etc.
589 a\(bc\)\{1,2}d "abcd" or "abcbcd"
590 a[bc]\{-}[cd] "abc" in "abcd"
591 a[bc]*[cd] "abcd" in "abcd"
592
593 The } may optionally be preceded with a backslash: \{n,m\}.
594
595 */\@=*
596\@= Matches the preceding atom with zero width. {not in Vi}
597 Like "(?=pattern)" in Perl.
598 Example matches ~
599 foo\(bar\)\@= "foo" in "foobar"
600 foo\(bar\)\@=foo nothing
601 */zero-width*
602 When using "\@=" (or "^", "$", "\<", "\>") no characters are included
603 in the match. These items are only used to check if a match can be
604 made. This can be tricky, because a match with following items will
605 be done in the same position. The last example above will not match
606 "foobarfoo", because it tries match "foo" in the same position where
607 "bar" matched.
608
609 Note that using "\&" works the same as using "\@=": "foo\&.." is the
610 same as "\(foo\)\@=..". But using "\&" is easier, you don't need the
611 braces.
612
613
614 */\@!*
615\@! Matches with zero width if the preceding atom does NOT match at the
616 current position. |/zero-width| {not in Vi}
617 Like '(?!pattern)" in Perl.
618 Example matches ~
619 foo\(bar\)\@! any "foo" not followed by "bar"
620 a.\{-}p\@! "a", "ap", "app", etc. not followed by a "p"
621 if \(\(then\)\@!.\)*$ "if " not followed by "then"
622
623 Using "\@!" is tricky, because there are many places where a pattern
624 does not match. "a.*p\@!" will match from an "a" to the end of the
625 line, because ".*" can match all characters in the line and the "p"
626 doesn't match at the end of the line. "a.\{-}p\@!" will match any
627 "a", "ap", "aap", etc. that isn't followed by a "p", because the "."
628 can match a "p" and "p\@!" doesn't match after that.
629
630 You can't use "\@!" to look for a non-match before the matching
631 position: "\(foo\)\@!bar" will match "bar" in "foobar", because at the
632 position where "bar" matches, "foo" does not match. To avoid matching
633 "foobar" you could use "\(foo\)\@!...bar", but that doesn't match a
Bram Moolenaar13fcaaf2005-04-15 21:13:42 +0000634 bar at the start of a line. Use "\(foo\)\@<!bar".
Bram Moolenaar071d4272004-06-13 20:20:40 +0000635
636 */\@<=*
637\@<= Matches with zero width if the preceding atom matches just before what
638 follows. |/zero-width| {not in Vi}
639 Like '(?<=pattern)" in Perl, but Vim allows non-fixed-width patterns.
640 Example matches ~
641 \(an\_s\+\)\@<=file "file" after "an" and white space or an
642 end-of-line
643 For speed it's often much better to avoid this multi. Try using "\zs"
644 instead |/\zs|. To match the same as the above example:
645 an\_s\+\zsfile
646
647 "\@<=" and "\@<!" check for matches just before what follows.
648 Theoretically these matches could start anywhere before this position.
649 But to limit the time needed, only the line where what follows matches
650 is searched, and one line before that (if there is one). This should
651 be sufficient to match most things and not be too slow.
652 The part of the pattern after "\@<=" and "\@<!" are checked for a
653 match first, thus things like "\1" don't work to reference \(\) inside
654 the preceding atom. It does work the other way around:
655 Example matches ~
656 \1\@<=,\([a-z]\+\) ",abc" in "abc,abc"
657
658 */\@<!*
659\@<! Matches with zero width if the preceding atom does NOT match just
660 before what follows. Thus this matches if there is no position in the
661 current or previous line where the atom matches such that it ends just
662 before what follows. |/zero-width| {not in Vi}
663 Like '(?<!pattern)" in Perl, but Vim allows non-fixed-width patterns.
664 The match with the preceding atom is made to end just before the match
665 with what follows, thus an atom that ends in ".*" will work.
666 Warning: This can be slow (because many positions need to be checked
667 for a match).
668 Example matches ~
669 \(foo\)\@<!bar any "bar" that's not in "foobar"
670 \(\/\/.*\)\@\<!in "in" which is not after "//"
671
672 */\@>*
673\@> Matches the preceding atom like matching a whole pattern. {not in Vi}
674 Like '(?>pattern)" in Perl.
675 Example matches ~
676 \(a*\)\@>a nothing (the "a*" takes all the "a"'s, there can't be
677 another one following)
678
679 This matches the preceding atom as if it was a pattern by itself. If
680 it doesn't match, there is no retry with shorter sub-matches or
681 anything. Observe this difference: "a*b" and "a*ab" both match
682 "aaab", but in the second case the "a*" matches only the first two
683 "a"s. "\(a*\)\@>ab" will not match "aaab", because the "a*" matches
684 the "aaa" (as many "a"s as possible), thus the "ab" can't match.
685
686
687==============================================================================
6886. Ordinary atoms *pattern-atoms*
689
690An ordinary atom can be:
691
692 */^*
693^ At beginning of pattern or after "\|", "\(", "\%(" or "\n": matches
694 start-of-line; at other positions, matches literal '^'. |/zero-width|
695 Example matches ~
696 ^beep( the start of the C function "beep" (probably).
697
698 */\^*
699\^ Matches literal '^'. Can be used at any position in the pattern.
700
701 */\_^*
702\_^ Matches start-of-line. |/zero-width| Can be used at any position in
703 the pattern.
704 Example matches ~
705 \_s*\_^foo white space and blank lines and then "foo" at
706 start-of-line
707
708 */$*
709$ At end of pattern or in front of "\|" or "\)" ("|" or ")" after "\v"):
710 matches end-of-line <EOL>; at other positions, matches literal '$'.
711 |/zero-width|
712
713 */\$*
714\$ Matches literal '$'. Can be used at any position in the pattern.
715
716 */\_$*
717\_$ Matches end-of-line. |/zero-width| Can be used at any position in the
718 pattern. Note that "a\_$b" never matches, since "b" cannot match an
719 end-of-line. Use "a\nb" instead |/\n|.
720 Example matches ~
721 foo\_$\_s* "foo" at end-of-line and following white space and
722 blank lines
723
724. (with 'nomagic': \.) */.* */\.*
725 Matches any single character, but not an end-of-line.
726
727 */\_.*
728\_. Matches any single character or end-of-line.
729 Careful: "\_.*" matches all text to the end of the buffer!
730
731 */\<*
732\< Matches the beginning of a word: The next char is the first char of a
733 word. The 'iskeyword' option specifies what is a word character.
734 |/zero-width|
735
736 */\>*
737\> Matches the end of a word: The previous char is the last char of a
Bram Moolenaar13fcaaf2005-04-15 21:13:42 +0000738 word. The 'iskeyword' option specifies what is a word character.
Bram Moolenaar071d4272004-06-13 20:20:40 +0000739 |/zero-width|
740
741 */\zs*
742\zs Matches at any position, and sets the start of the match there: The
743 next char is the first char of the whole match. |/zero-width|
744 Example: >
745 /^\s*\zsif
746< matches an "if" at the start of a line, ignoring white space.
747 Can be used multiple times, the last one encountered in a matching
Bram Moolenaar13fcaaf2005-04-15 21:13:42 +0000748 branch is used. Example: >
Bram Moolenaar071d4272004-06-13 20:20:40 +0000749 /\(.\{-}\zsFab\)\{3}
750< Finds the third occurrence of "Fab".
751 {not in Vi} {not available when compiled without the +syntax feature}
752 */\ze*
753\ze Matches at any position, and sets the end of the match there: The
754 previous char is the last char of the whole match. |/zero-width|
755 Can be used multiple times, the last one encountered in a matching
756 branch is used.
757 Example: "end\ze\(if\|for\)" matches the "end" in "endif" and
758 "endfor".
759 {not in Vi} {not available when compiled without the +syntax feature}
760
761 */\%^* *start-of-file*
762\%^ Matches start of the file. When matching with a string, matches the
763 start of the string. {not in Vi}
764 For example, to find the first "VIM" in a file: >
765 /\%^\_.\{-}\zsVIM
766<
767 */\%$* *end-of-file*
768\%$ Matches end of the file. When matching with a string, matches the
769 end of the string. {not in Vi}
770 Note that this does NOT find the last "VIM" in a file: >
771 /VIM\_.\{-}\%$
772< It will find the next VIM, because the part after it will always
773 match. This one will find the last "VIM" in the file: >
774 /VIM\ze\(\(VIM\)\@!\_.\)*\%$
775< This uses |/\@!| to ascertain that "VIM" does NOT match in any
776 position after the first "VIM".
777 Searching from the end of the file backwards is easier!
778
779 */\%#* *cursor-position*
780\%# Matches with the cursor position. Only works when matching in a
781 buffer displayed in a window. {not in Vi}
782 WARNING: When the cursor is moved after the pattern was used, the
783 result becomes invalid. Vim doesn't automatically update the matches.
784 This is especially relevant for syntax highlighting and 'hlsearch'.
785 In other words: When the cursor moves the display isn't updated for
786 this change. An update is done for lines which are changed (the whole
787 line is updated) or when using the |CTRL-L| command (the whole screen
788 is updated). Example, to highlight the word under the cursor: >
789 /\k*\%#\k*
790< When 'hlsearch' is set and you move the cursor around and make changes
791 this will clearly show when the match is updated or not.
792
793 */\%l* */\%>l* */\%<l*
794\%23l Matches in a specific line.
795\%<23l Matches above a specific line.
796\%>23l Matches below a specific line.
797 These three can be used to match specific lines in a buffer. The "23"
798 can be any line number. The first line is 1. {not in Vi}
799 WARNING: When inserting or deleting lines Vim does not automatically
800 update the matches. This means Syntax highlighting quickly becomes
801 wrong.
802 Example, to highlight the line where the cursor currently is: >
803 :exe '/\%' . line(".") . 'l.*'
804< When 'hlsearch' is set and you move the cursor around and make changes
805 this will clearly show when the match is updated or not.
806
807 */\%c* */\%>c* */\%<c*
808\%23c Matches in a specific column.
809\%<23c Matches before a specific column.
810\%>23c Matches after a specific column.
811 These three can be used to match specific columns in a buffer or
812 string. The "23" can be any column number. The first column is 1.
813 Actually, the column is the byte number (thus it's not exactly right
814 for multi-byte characters). {not in Vi}
815 WARNING: When inserting or deleting text Vim does not automatically
816 update the matches. This means Syntax highlighting quickly becomes
817 wrong.
818 Example, to highlight the column where the cursor currently is: >
819 :exe '/\%' . col(".") . 'c'
820< When 'hlsearch' is set and you move the cursor around and make changes
821 this will clearly show when the match is updated or not.
822 Example for matching a single byte in column 44: >
823 /\%>43c.\%<46c
824< Note that "\%<46c" matches in column 45 when the "." matches a byte in
825 column 44.
826 */\%v* */\%>v* */\%<v*
827\%23v Matches in a specific virtual column.
828\%<23v Matches before a specific virtual column.
829\%>23v Matches after a specific virtual column.
830 These three can be used to match specific virtual columns in a buffer
831 or string. When not matching with a buffer in a window, the option
832 values of the current window are used (e.g., 'tabstop').
833 The "23" can be any column number. The first column is 1.
834 Note that some virtual column positions will never match, because they
835 are halfway a Tab or other character that occupies more than one
836 screen character. {not in Vi}
837 WARNING: When inserting or deleting text Vim does not automatically
Bram Moolenaarde934d72005-05-22 22:09:40 +0000838 update highlighted matches. This means Syntax highlighting quickly
839 becomes wrong.
Bram Moolenaar071d4272004-06-13 20:20:40 +0000840 Example, to highlight the all characters after virtual column 72: >
841 /\%>72v.*
842< When 'hlsearch' is set and you move the cursor around and make changes
843 this will clearly show when the match is updated or not.
844 To match the text up to column 17: >
845 /.*\%17v
846< Column 17 is not included, because that's where the "\%17v" matches,
847 and since this is a |/zero-width| match, column 17 isn't included in
848 the match. This does the same: >
849 /.*\%<18v
850<
851
852Character classes: {not in Vi}
853\i identifier character (see 'isident' option) */\i*
854\I like "\i", but excluding digits */\I*
855\k keyword character (see 'iskeyword' option) */\k*
856\K like "\k", but excluding digits */\K*
857\f file name character (see 'isfname' option) */\f*
858\F like "\f", but excluding digits */\F*
859\p printable character (see 'isprint' option) */\p*
860\P like "\p", but excluding digits */\P*
861
862NOTE: the above also work for multi-byte characters. The ones below only
863match ASCII characters, as indicated by the range.
864
865 *whitespace* *white-space*
866\s whitespace character: <Space> and <Tab> */\s*
867\S non-whitespace character; opposite of \s */\S*
868\d digit: [0-9] */\d*
869\D non-digit: [^0-9] */\D*
870\x hex digit: [0-9A-Fa-f] */\x*
871\X non-hex digit: [^0-9A-Fa-f] */\X*
872\o octal digit: [0-7] */\o*
873\O non-octal digit: [^0-7] */\O*
874\w word character: [0-9A-Za-z_] */\w*
875\W non-word character: [^0-9A-Za-z_] */\W*
876\h head of word character: [A-Za-z_] */\h*
877\H non-head of word character: [^A-Za-z_] */\H*
878\a alphabetic character: [A-Za-z] */\a*
879\A non-alphabetic character: [^A-Za-z] */\A*
880\l lowercase character: [a-z] */\l*
881\L non-lowercase character: [^a-z] */\L*
882\u uppercase character: [A-Z] */\u*
883\U non-uppercase character [^A-Z] */\U*
884
885 NOTE: Using the atom is faster than the [] form.
886
887 NOTE: 'ignorecase', "\c" and "\C" are not used by character classes.
888
889 */\_* *E63* */\_i* */\_I* */\_k* */\_K* */\_f* */\_F*
890 */\_p* */\_P* */\_s* */\_S* */\_d* */\_D* */\_x* */\_X*
891 */\_o* */\_O* */\_w* */\_W* */\_h* */\_H* */\_a* */\_A*
892 */\_l* */\_L* */\_u* */\_U*
893\_x Where "x" is any of the characters above: The character class with
894 end-of-line added
895(end of character classes)
896
897\e matches <Esc> */\e*
898\t matches <Tab> */\t*
899\r matches <CR> */\r*
900\b matches <BS> */\b*
901\n matches an end-of-line */\n*
902 When matching in a string instead of buffer text a literal newline
903 character is matched.
904
905~ matches the last given substitute string */~* */\~*
906
907\(\) A pattern enclosed by escaped parentheses. */\(* */\(\)* */\)*
908 E.g., "\(^a\)" matches 'a' at the start of a line. *E51* *E54* *E55*
909
910\1 Matches the same string that was matched by */\1* *E65*
911 the first sub-expression in \( and \). {not in Vi}
912 Example: "\([a-z]\).\1" matches "ata", "ehe", "tot", etc.
913\2 Like "\1", but uses second sub-expression, */\2*
914 ... */\3*
915\9 Like "\1", but uses ninth sub-expression. */\9*
916 Note: The numbering of groups is done based on which "\(" comes first
917 in the pattern (going left to right), NOT based on what is matched
918 first.
919
920\%(\) A pattern enclosed by escaped parentheses. */\%(\)* */\%(* *E53*
921 Just like \(\), but without counting it as a sub-expression. This
922 allows using more groups and it's a little bit faster.
923 {not in Vi}
924
925x A single character, with no special meaning, matches itself
926
927 */\* */\\*
928\x A backslash followed by a single character, with no special meaning,
929 is reserved for future expansions
930
931[] (with 'nomagic': \[]) */[]* */\[]* */\_[]* */collection*
932\_[]
Bram Moolenaar13fcaaf2005-04-15 21:13:42 +0000933 A collection. This is a sequence of characters enclosed in brackets.
Bram Moolenaar071d4272004-06-13 20:20:40 +0000934 It matches any single character in the collection.
935 Example matches ~
936 [xyz] any 'x', 'y' or 'z'
937 [a-zA-Z]$ any alphabetic character at the end of a line
938 \c[a-z]$ same
939
940 With "\_" prepended the collection also includes the end-of-line.
941 The same can be done by including "\n" in the collection. The
942 end-of-line is also matched when the collection starts with "^"! Thus
943 "\_[^ab]" matches the end-of-line and any character but "a" and "b".
944 This makes it Vi compatible: Without the "\_" or "\n" the collection
945 does not match an end-of-line.
Bram Moolenaar8aff23a2005-08-19 20:40:30 +0000946 *E769*
Bram Moolenaarae5bce12005-08-15 21:41:48 +0000947 When the ']' is not there Vim will not give an error message but
Bram Moolenaar8aff23a2005-08-19 20:40:30 +0000948 assume no collection is used. Useful to search for '['. However, you
949 do get E769 for internal searching.
Bram Moolenaarae5bce12005-08-15 21:41:48 +0000950
Bram Moolenaar071d4272004-06-13 20:20:40 +0000951 If the sequence begins with "^", it matches any single character NOT
952 in the collection: "[^xyz]" matches anything but 'x', 'y' and 'z'.
953 - If two characters in the sequence are separated by '-', this is
954 shorthand for the full list of ASCII characters between them. E.g.,
955 "[0-9]" matches any decimal digit.
956 - A character class expression is evaluated to the set of characters
957 belonging to that character class. The following character classes
958 are supported:
959 Name Contents ~
960*[:alnum:]* [:alnum:] letters and digits
961*[:alpha:]* [:alpha:] letters
962*[:blank:]* [:blank:] space and tab characters
963*[:cntrl:]* [:cntrl:] control characters
964*[:digit:]* [:digit:] decimal digits
965*[:graph:]* [:graph:] printable characters excluding space
966*[:lower:]* [:lower:] lowercase letters (all letters when
967 'ignorecase' is used)
968*[:print:]* [:print:] printable characters including space
969*[:punct:]* [:punct:] punctuation characters
970*[:space:]* [:space:] whitespace characters
971*[:upper:]* [:upper:] uppercase letters (all letters when
972 'ignorecase' is used)
973*[:xdigit:]* [:xdigit:] hexadecimal digits
974*[:return:]* [:return:] the <CR> character
975*[:tab:]* [:tab:] the <Tab> character
976*[:escape:]* [:escape:] the <Esc> character
977*[:backspace:]* [:backspace:] the <BS> character
978 The brackets in character class expressions are additional to the
979 brackets delimiting a collection. For example, the following is a
980 plausible pattern for a UNIX filename: "[-./[:alnum:]_~]\+" That is,
981 a list of at least one character, each of which is either '-', '.',
982 '/', alphabetic, numeric, '_' or '~'.
983 These items only work for 8-bit characters.
Bram Moolenaar26a60b42005-02-22 08:49:11 +0000984 */[[=* *[==]*
985 - An equivalence class. This means that characters are matched that
986 have almost the same meaning, e.g., when ignoring accents. The form
987 is:
988 [=a=]
989 Currrently this is only implemented for latin1. Also works for the
990 latin1 characters in utf-8 and latin9.
991 */[[.* *[..]*
992 - A collation element. This currently simply accepts a single
993 character in the form:
994 [.a.]
Bram Moolenaar071d4272004-06-13 20:20:40 +0000995 */\]*
996 - To include a literal ']', '^', '-' or '\' in the collection, put a
997 backslash before it: "[xyz\]]", "[\^xyz]", "[xy\-z]" and "[xyz\\]".
998 (Note: POSIX does not support the use of a backslash this way). For
999 ']' you can also make it the first character (following a possible
1000 "^"): "[]xyz]" or "[^]xyz]" {not in Vi}.
1001 For '-' you can also make it the first or last character: "[-xyz]",
1002 "[^-xyz]" or "[xyz-]". For '\' you can also let it be followed by
1003 any character that's not in "^]-\bertn". "[\xyz]" matches '\', 'x',
1004 'y' and 'z'. It's better to use "\\" though, future expansions may
1005 use other characters after '\'.
1006 - The following translations are accepted when the 'l' flag is not
1007 included in 'cpoptions' {not in Vi}:
1008 \e <Esc>
1009 \t <Tab>
1010 \r <CR> (NOT end-of-line!)
1011 \b <BS>
Bram Moolenaarc0197e22004-09-13 20:26:32 +00001012 \d123 decimal number of character
1013 \o40 octal number of character up to 0377
1014 \x20 hexadecimal number of character up to 0xff
1015 \u20AC hex. number of multibyte character up to 0xffff
1016 \U1234 hex. number of multibyte character up to 0xffffffff
Bram Moolenaar071d4272004-06-13 20:20:40 +00001017 NOTE: The other backslash codes mentioned above do not work inside
1018 []!
1019 - Matching with a collection can be slow, because each character in
1020 the text has to be compared with each character in the collection.
1021 Use one of the other atoms above when possible. Example: "\d" is
1022 much faster than "[0-9]" and matches the same characters.
1023
1024 */\%[]* *E69* *E70* *E369*
Bram Moolenaarc0197e22004-09-13 20:26:32 +00001025\%[] A sequence of optionally matched atoms. This always matches.
Bram Moolenaar071d4272004-06-13 20:20:40 +00001026 It matches as much of the list of atoms it contains as possible. Thus
1027 it stops at the first atom that doesn't match. For example: >
1028 /r\%[ead]
1029< matches "r", "re", "rea" or "read". The longest that matches is used.
1030 To match the Ex command "function", where "fu" is required and
1031 "nction" is optional, this would work: >
1032 /\<fu\%[nction]\>
1033< The end-of-word atom "\>" is used to avoid matching "fu" in "full".
1034 It gets more complicated when the atoms are not ordinary characters.
1035 You don't often have to use it, but it is possible. Example: >
1036 /\<r\%[[eo]ad]\>
1037< Matches the words "r", "re", "ro", "rea", "roa", "read" and "road".
1038 {not available when compiled without the +syntax feature}
1039
Bram Moolenaar677ee682005-01-27 14:41:15 +00001040 */\%d* */\%x* */\%o* */\%u* */\%U* *E678*
Bram Moolenaarc0197e22004-09-13 20:26:32 +00001041
1042\%d123 Matches the character specified with a decimal number. Must be
1043 followed by a non-digit.
1044\%o40 Matches the character specified with an octal number up to 0377.
1045 Numbers below 040 must be followed by a non-octal digit or a non-digit.
1046\%x2a Matches the character specified with up to two hexadecimal characters.
1047\%u20AC Matches the character specified with up to four hexadecimal
1048 characters.
1049\%U1234abcd Matches the character specified with up to eight hexadecimal
1050 characters.
Bram Moolenaar071d4272004-06-13 20:20:40 +00001051
1052==============================================================================
10537. Ignoring case in a pattern */ignorecase*
1054
1055If the 'ignorecase' option is on, the case of normal letters is ignored.
1056'smartcase' can be set to ignore case when the pattern contains lowercase
1057letters only.
1058 */\c* */\C*
1059When "\c" appears anywhere in the pattern, the whole pattern is handled like
1060'ignorecase' is on. The actual value of 'ignorecase' and 'smartcase' is
1061ignored. "\C" does the opposite: Force matching case for the whole pattern.
1062{only Vim supports \c and \C}
1063Note that 'ignorecase', "\c" and "\C" are not used for the character classes.
1064
1065Examples:
1066 pattern 'ignorecase' 'smartcase' matches ~
1067 foo off - foo
1068 foo on - foo Foo FOO
1069 Foo on off foo Foo FOO
1070 Foo on on Foo
1071 \cfoo - - foo Foo FOO
1072 foo\C - - foo
1073
1074 */\Z*
1075When "\Z" appears anywhere in the pattern, composing characters are ignored.
1076Thus only the base characters need to match, the composing characters may be
1077different and the number of composing characters may differ. Only relevant
1078when 'encoding' is "utf-8".
1079
1080Technical detail: *NL-used-for-Nul*
1081<Nul> characters in the file are stored as <NL> in memory. In the display
1082they are shown as "^@". The translation is done when reading and writing
1083files. To match a <Nul> with a search pattern you can just enter CTRL-@ or
1084"CTRL-V 000". This is probably just what you expect. Internally the
1085character is replaced with a <NL> in the search pattern. What is unusual is
1086that typing CTRL-V CTRL-J also inserts a <NL>, thus also searches for a <Nul>
1087in the file. {Vi cannot handle <Nul> characters in the file at all}
1088
1089 *CR-used-for-NL*
1090When 'fileformat' is "mac", <NL> characters in the file are stored as <CR>
1091characters internally. In the display they are shown as "^M". Otherwise this
1092works similar to the usage of <NL> for a <Nul>.
1093
1094When working with expression evaluation, a <NL> character in the pattern
1095matches a <NL> in the string. The use of "\n" (backslash n) to match a <NL>
1096doesn't work there, it only works to match text in the buffer.
1097
1098 *pattern-multi-byte*
1099Patterns will also work with multi-byte characters, mostly as you would
1100expect. But invalid bytes may cause trouble, a pattern with an invalid byte
1101will probably never match.
1102
1103==============================================================================
11048. Compare with Perl patterns *perl-patterns*
1105
1106Vim's regexes are most similar to Perl's, in terms of what you can do. The
1107difference between them is mostly just notation; here's a summary of where
1108they differ:
1109
1110Capability in Vimspeak in Perlspeak ~
1111----------------------------------------------------------------
1112force case insensitivity \c (?i)
1113force case sensitivity \C (?-i)
1114backref-less grouping \%(atom) (?:atom)
1115conservative quantifiers \{-n,m} *?, +?, ??, {}?
11160-width match atom\@= (?=atom)
11170-width non-match atom\@! (?!atom)
11180-width preceding match atom\@<= (?<=atom)
11190-width preceding non-match atom\@<! (?<!atom)
1120match without retry atom\@> (?>atom)
1121
1122Vim and Perl handle newline characters inside a string a bit differently:
1123
1124In Perl, ^ and $ only match at the very beginning and end of the text,
1125by default, but you can set the 'm' flag, which lets them match at
1126embedded newlines as well. You can also set the 's' flag, which causes
1127a . to match newlines as well. (Both these flags can be changed inside
1128a pattern using the same syntax used for the i flag above, BTW.)
1129
1130On the other hand, Vim's ^ and $ always match at embedded newlines, and
1131you get two separate atoms, \%^ and \%$, which only match at the very
1132start and end of the text, respectively. Vim solves the second problem
1133by giving you the \_ "modifier": put it in front of a . or a character
1134class, and they will match newlines as well.
1135
1136Finally, these constructs are unique to Perl:
1137- execution of arbitrary code in the regex: (?{perl code})
1138- conditional expressions: (?(condition)true-expr|false-expr)
1139
1140...and these are unique to Vim:
1141- changing the magic-ness of a pattern: \v \V \m \M
1142 (very useful for avoiding backslashitis)
1143- sequence of optionally matching atoms: \%[atoms]
1144- \& (which is to \| what "and" is to "or"; it forces several branches
1145 to match at one spot)
1146- matching lines/columns by number: \%5l \%5c \%5v
1147- limiting the "return value" of a regex: \zs \ze
1148
1149==============================================================================
11509. Highlighting matches *match-highlight*
1151
1152 *:mat* *:match*
1153:mat[ch] {group} /{pattern}/
1154 Define a pattern to highlight in the current window. It will
1155 be highlighted with {group}. Example: >
1156 :highlight MyGroup ctermbg=green guibg=green
1157 :match MyGroup /TODO/
1158< Instead of // any character can be used to mark the start and
1159 end of the {pattern}. Watch out for using special characters,
1160 such as '"' and '|'.
1161 {group} must exist at the moment this command is executed.
1162 The match overrides the 'hlsearch' highlighting.
1163 'ignorecase' does not apply, use |/\c| in the pattern to
1164 ignore case. Otherwise case is not ignored.
1165 Note that highlighting the last used search pattern with
1166 'hlsearch' is used in all windows, while the pattern defined
1167 with ":match" only exists in the current window. It is kept
1168 when switching to another buffer.
1169 Another example, which highlights all characters in virtual
1170 column 72 and more: >
1171 :highlight rightMargin term=bold ctermfg=blue guifg=blue
1172 :match rightMargin /.\%>72v/
1173< To highlight all character that are in virtual column 7: >
1174 :highlight col8 ctermbg=grey guibg=grey
1175 :match col8 /\%<8v.\%>7v/
1176< Note the use of two items to also match a character that
1177 occupies more than one virtual column, such as a TAB.
1178
1179:mat[ch]
1180:mat[ch] none
1181 Clear a previously defined match pattern.
1182
1183 vim:tw=78:ts=8:ft=help:norl: