xref: /vim-8.2.3635/runtime/doc/pattern.txt (revision 044b68f4)
1*pattern.txt*   For Vim version 7.1a.  Last change: 2007 Apr 24
2
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. Composing characters		|patterns-composing|
209. Compare with Perl patterns	|perl-patterns|
2110. Highlighting matches	|match-highlight|
22
23==============================================================================
241. Search commands				*search-commands* *E486*
25
26							*/*
27/{pattern}[/]<CR>	Search forward for the [count]'th occurrence of
28			{pattern} |exclusive|.
29
30/{pattern}/{offset}<CR>	Search forward for the [count]'th occurrence of
31			{pattern} and go |{offset}| lines up or down.
32			|linewise|.
33
34							*/<CR>*
35/<CR>			Search forward for the [count]'th latest used
36			pattern |last-pattern| with latest used |{offset}|.
37
38//{offset}<CR>		Search forward for the [count]'th latest used
39			pattern |last-pattern| with new |{offset}|.  If
40			{offset} is empty no offset is used.
41
42							*?*
43?{pattern}[?]<CR>	Search backward for the [count]'th previous
44			occurrence of {pattern} |exclusive|.
45
46?{pattern}?{offset}<CR>	Search backward for the [count]'th previous
47			occurrence of {pattern} and go |{offset}| lines up or
48			down |linewise|.
49
50							*?<CR>*
51?<CR>			Search backward for the [count]'th latest used
52			pattern |last-pattern| with latest used |{offset}|.
53
54??{offset}<CR>		Search backward for the [count]'th latest used
55			pattern |last-pattern| with new |{offset}|.  If
56			{offset} is empty no offset is used.
57
58							*n*
59n			Repeat the latest "/" or "?" [count] times.
60			|last-pattern| {Vi: no count}
61
62							*N*
63N			Repeat the latest "/" or "?" [count] times in
64			opposite direction. |last-pattern| {Vi: no count}
65
66							*star* *E348* *E349*
67*			Search forward for the [count]'th occurrence of the
68			word nearest to the cursor.  The word used for the
69			search is the first of:
70				1. the keyword under the cursor |'iskeyword'|
71				2. the first keyword after the cursor, in the
72				   current line
73				3. the non-blank word under the cursor
74				4. the first non-blank word after the cursor,
75				   in the current line
76			Only whole keywords are searched for, like with the
77			command "/\<keyword\>".  |exclusive|  {not in Vi}
78			'ignorecase' is used, 'smartcase' is not.
79
80							*#*
81#			Same as "*", but search backward.  The pound sign
82			(character 163) also works.  If the "#" key works as
83			backspace, try using "stty erase <BS>" before starting
84			Vim (<BS> is CTRL-H or a real backspace).  {not in Vi}
85
86							*gstar*
87g*			Like "*", but don't put "\<" and "\>" around the word.
88			This makes the search also find matches that are not a
89			whole word.  {not in Vi}
90
91							*g#*
92g#			Like "#", but don't put "\<" and "\>" around the word.
93			This makes the search also find matches that are not a
94			whole word.  {not in Vi}
95
96							*gd*
97gd			Goto local Declaration.  When the cursor is on a local
98			variable, this command will jump to its declaration.
99			First Vim searches for the start of the current
100			function, just like "[[".  If it is not found the
101			search stops in line 1.  If it is found, Vim goes back
102			until a blank line is found.  From this position Vim
103			searches for the keyword under the cursor, like with
104			"*", but lines that look like a comment are ignored
105			(see 'comments' option).
106			Note that this is not guaranteed to work, Vim does not
107			really check the syntax, it only searches for a match
108			with the keyword.  If included files also need to be
109			searched use the commands listed in |include-search|.
110			After this command |n| searches forward for the next
111			match (not backward).
112			{not in Vi}
113
114							*gD*
115gD			Goto global Declaration.  When the cursor is on a
116			global variable that is defined in the file, this
117			command will jump to its declaration.  This works just
118			like "gd", except that the search for the keyword
119			always starts in line 1.  {not in Vi}
120
121							*1gd*
1221gd			Like "gd", but ignore matches inside a {} block that
123			ends before the cursor position. {not in Vi}
124
125							*1gD*
1261gD			Like "gD", but ignore matches inside a {} block that
127			ends before the cursor position. {not in Vi}
128
129							*CTRL-C*
130CTRL-C			Interrupt current (search) command.  Use CTRL-Break on
131			MS-DOS |dos-CTRL-Break|.
132			In Normal mode, any pending command is aborted.
133
134							*:noh* *:nohlsearch*
135:noh[lsearch]		Stop the highlighting for the 'hlsearch' option.  It
136			is automatically turned back on when using a search
137			command, or setting the 'hlsearch' option.
138			This command doesn't work in an autocommand, because
139			the highlighting state is saved and restored when
140			executing autocommands |autocmd-searchpat|.
141
142While typing the search pattern the current match will be shown if the
143'incsearch' option is on.  Remember that you still have to finish the search
144command with <CR> to actually position the cursor at the displayed match.  Or
145use <Esc> to abandon the search.
146
147All matches for the last used search pattern will be highlighted if you set
148the 'hlsearch' option.  This can be suspended with the |:nohlsearch| command.
149
150					*search-offset* *{offset}*
151These commands search for the specified pattern.  With "/" and "?" an
152additional offset may be given.  There are two types of offsets: line offsets
153and character offsets.  {the character offsets are not in Vi}
154
155The offset gives the cursor position relative to the found match:
156    [num]	[num] lines downwards, in column 1
157    +[num]	[num] lines downwards, in column 1
158    -[num]	[num] lines upwards, in column 1
159    e[+num]	[num] characters to the right of the end of the match
160    e[-num]	[num] characters to the left of the end of the match
161    s[+num]	[num] characters to the right of the start of the match
162    s[-num]	[num] characters to the left of the start of the match
163    b[+num]	[num] identical to s[+num] above (mnemonic: begin)
164    b[-num]	[num] identical to s[-num] above (mnemonic: begin)
165    ;{pattern}  perform another search, see |//;|
166
167If a '-' or '+' is given but [num] is omitted, a count of one will be used.
168When including an offset with 'e', the search becomes inclusive (the
169character the cursor lands on is included in operations).
170
171Examples:
172
173pattern			cursor position	~
174/test/+1		one line below "test", in column 1
175/test/e			on the last t of "test"
176/test/s+2		on the 's' of "test"
177/test/b-3		three characters before "test"
178
179If one of these commands is used after an operator, the characters between
180the cursor position before and after the search is affected.  However, if a
181line offset is given, the whole lines between the two cursor positions are
182affected.
183
184An example of how to search for matches with a pattern and change the match
185with another word: >
186	/foo<CR>	find "foo"
187	c//e		change until end of match
188	bar<Esc>	type replacement
189	//<CR>		go to start of next match
190	c//e		change until end of match
191	beep<Esc>	type another replacement
192			etc.
193<
194							*//;* *E386*
195A very special offset is ';' followed by another search command.  For example: >
196
197   /test 1/;/test
198   /test.*/+1;?ing?
199
200The first one first finds the next occurrence of "test 1", and then the first
201occurrence of "test" after that.
202
203This is like executing two search commands after each other, except that:
204- It can be used as a single motion command after an operator.
205- The direction for a following "n" or "N" command comes from the first
206  search command.
207- When an error occurs the cursor is not moved at all.
208
209							*last-pattern*
210The last used pattern and offset are remembered.  They can be used to repeat
211the search, possibly in another direction or with another count.  Note that
212two patterns are remembered: One for 'normal' search commands and one for the
213substitute command ":s".  Each time an empty pattern is given, the previously
214used pattern is used.
215
216The 'magic' option sticks with the last used pattern.  If you change 'magic',
217this will not change how the last used pattern will be interpreted.
218The 'ignorecase' option does not do this.  When 'ignorecase' is changed, it
219will result in the pattern to match other text.
220
221All matches for the last used search pattern will be highlighted if you set
222the 'hlsearch' option.
223
224To clear the last used search pattern: >
225	:let @/ = ""
226This will not set the pattern to an empty string, because that would match
227everywhere.  The pattern is really cleared, like when starting Vim.
228
229The search usually skips matches that don't move the cursor.  Whether the next
230match is found at the next character or after the skipped match depends on the
231'c' flag in 'cpoptions'.  See |cpo-c|.
232	   with 'c' flag:   "/..." advances 1 to 3 characters
233	without 'c' flag:   "/..." advances 1 character
234The unpredictability with the 'c' flag is caused by starting the search in the
235first column, skipping matches until one is found past the cursor position.
236
237When searching backwards, searching starts at the start of the line, using the
238'c' flag in 'cpoptions' as described above.  Then the last match before the
239cursor position is used.
240
241In Vi the ":tag" command sets the last search pattern when the tag is searched
242for.  In Vim this is not done, the previous search pattern is still remembered,
243unless the 't' flag is present in 'cpoptions'.  The search pattern is always
244put in the search history.
245
246If the 'wrapscan' option is on (which is the default), searches wrap around
247the end of the buffer.  If 'wrapscan' is not set, the backward search stops
248at the beginning and the forward search stops at the end of the buffer.  If
249'wrapscan' is set and the pattern was not found the error message "pattern
250not found" is given, and the cursor will not be moved.  If 'wrapscan' is not
251set the message becomes "search hit BOTTOM without match" when searching
252forward, or "search hit TOP without match" when searching backward.  If
253wrapscan is set and the search wraps around the end of the file the message
254"search hit TOP, continuing at BOTTOM" or "search hit BOTTOM, continuing at
255TOP" is given when searching backwards or forwards respectively.  This can be
256switched off by setting the 's' flag in the 'shortmess' option.  The highlight
257method 'w' is used for this message (default: standout).
258
259							*search-range*
260You can limit the search command "/" to a certain range of lines by including
261\%>l items.  For example, to match the word "limit" below line 199 and above
262line 300: >
263	/\%>199l\%<300llimit
264Also see |/\%>l|.
265
266Another way is to use the ":substitute" command with the 'c' flag.  Example: >
267   :.,300s/Pattern//gc
268This command will search from the cursor position until line 300 for
269"Pattern".  At the match, you will be asked to type a character.  Type 'q' to
270stop at this match, type 'n' to find the next match.
271
272The "*", "#", "g*" and "g#" commands look for a word near the cursor in this
273order, the first one that is found is used:
274- The keyword currently under the cursor.
275- The first keyword to the right of the cursor, in the same line.
276- The WORD currently under the cursor.
277- The first WORD to the right of the cursor, in the same line.
278The keyword may only contain letters and characters in 'iskeyword'.
279The WORD may contain any non-blanks (<Tab>s and/or <Space>s).
280Note that if you type with ten fingers, the characters are easy to remember:
281the "#" is under your left hand middle finger (search to the left and up) and
282the "*" is under your right hand middle finger (search to the right and down).
283(this depends on your keyboard layout though).
284
285==============================================================================
2862. The definition of a pattern		*search-pattern* *pattern* *[pattern]*
287					*regular-expression* *regexp* *Pattern*
288					*E76* *E383* *E476*
289
290For starters, read chapter 27 of the user manual |usr_27.txt|.
291
292						*/bar* */\bar* */pattern*
2931. A pattern is one or more branches, separated by "\|".  It matches anything
294   that matches one of the branches.  Example: "foo\|beep" matches "foo" and
295   matches "beep".  If more than one branch matches, the first one is used.
296
297   pattern ::=	    branch
298		or  branch \| branch
299		or  branch \| branch \| branch
300		etc.
301
302						*/branch* */\&*
3032. A branch is one or more concats, separated by "\&".  It matches the last
304   concat, but only if all the preceding concats also match at the same
305   position.  Examples:
306	"foobeep\&..." matches "foo" in "foobeep".
307	".*Peter\&.*Bob" matches in a line containing both "Peter" and "Bob"
308
309   branch ::=	    concat
310		or  concat \& concat
311		or  concat \& concat \& concat
312		etc.
313
314						*/concat*
3153. A concat is one or more pieces, concatenated.  It matches a match for the
316   first piece, followed by a match for the second piece, etc.  Example:
317   "f[0-9]b", first matches "f", then a digit and then "b".
318
319   concat  ::=	    piece
320		or  piece piece
321		or  piece piece piece
322		etc.
323
324						*/piece*
3254. A piece is an atom, possibly followed by a multi, an indication of how many
326   times the atom can be matched.  Example: "a*" matches any sequence of "a"
327   characters: "", "a", "aa", etc.  See |/multi|.
328
329   piece   ::=	    atom
330		or  atom  multi
331
332						*/atom*
3335. An atom can be one of a long list of items.  Many atoms match one character
334   in the text.  It is often an ordinary character or a character class.
335   Braces can be used to make a pattern into an atom.  The "\z(\)" construct
336   is only for syntax highlighting.
337
338   atom    ::=	    ordinary-atom		|/ordinary-atom|
339		or  \( pattern \)		|/\(|
340		or  \%( pattern \)		|/\%(|
341		or  \z( pattern \)		|/\z(|
342
343
344==============================================================================
3453. Magic							*/magic*
346
347Some characters in the pattern are taken literally.  They match with the same
348character in the text.  When preceded with a backslash however, these
349characters get a special meaning.
350
351Other characters have a special meaning without a backslash.  They need to be
352preceded with a backslash to match literally.
353
354If a character is taken literally or not depends on the 'magic' option and the
355items mentioned next.
356							*/\m* */\M*
357Use of "\m" makes the pattern after it be interpreted as if 'magic' is set,
358ignoring the actual value of the 'magic' option.
359Use of "\M" makes the pattern after it be interpreted as if 'nomagic' is used.
360							*/\v* */\V*
361Use of "\v" means that in the pattern after it all ASCII characters except
362'0'-'9', 'a'-'z', 'A'-'Z' and '_' have a special meaning.  "very magic"
363
364Use of "\V" means that in the pattern after it only the backslash has a
365special meaning.  "very nomagic"
366
367Examples:
368after:	  \v	   \m	    \M	     \V		matches ~
369		'magic' 'nomagic'
370	  $	   $	    $	     \$		matches end-of-line
371	  .	   .	    \.	     \.		matches any character
372	  *	   *	    \*	     \*		any number of the previous atom
373	  ()	   \(\)     \(\)     \(\)	grouping into an atom
374	  |	   \|	    \|	     \|		separating alternatives
375	  \a	   \a	    \a	     \a		alphabetic character
376	  \\	   \\	    \\	     \\		literal backslash
377	  \.	   \.	    .	     .		literal dot
378	  \{	   {	    {	     {		literal '{'
379	  a	   a	    a	     a		literal 'a'
380
381{only Vim supports \m, \M, \v and \V}
382
383It is recommended to always keep the 'magic' option at the default setting,
384which is 'magic'.  This avoids portability problems.  To make a pattern immune
385to the 'magic' option being set or not, put "\m" or "\M" at the start of the
386pattern.
387
388==============================================================================
3894. Overview of pattern items				*pattern-overview*
390
391Overview of multi items.				*/multi* *E61* *E62*
392More explanation and examples below, follow the links.			*E64*
393
394	  multi ~
395     'magic' 'nomagic'	matches of the preceding atom ~
396|/star|	*	\*	0 or more	as many as possible
397|/\+|	\+	\+	1 or more	as many as possible (*)
398|/\=|	\=	\=	0 or 1		as many as possible (*)
399|/\?|	\?	\?	0 or 1		as many as possible (*)
400
401|/\{|	\{n,m}	\{n,m}	n to m		as many as possible (*)
402	\{n}	\{n}	n		exactly (*)
403	\{n,}	\{n,}	at least n	as many as possible (*)
404	\{,m}	\{,m}	0 to m		as many as possible (*)
405	\{}	\{}	0 or more	as many as possible (same as *) (*)
406
407|/\{-|	\{-n,m}	\{-n,m}	n to m		as few as possible (*)
408	\{-n}	\{-n}	n		exactly (*)
409	\{-n,}	\{-n,}	at least n	as few as possible (*)
410	\{-,m}	\{-,m}	0 to m		as few as possible (*)
411	\{-}	\{-}	0 or more	as few as possible (*)
412
413							*E59*
414|/\@>|	\@>	\@>	1, like matching a whole pattern (*)
415|/\@=|	\@=	\@=	nothing, requires a match |/zero-width| (*)
416|/\@!|	\@!	\@!	nothing, requires NO match |/zero-width| (*)
417|/\@<=|	\@<=	\@<=	nothing, requires a match behind |/zero-width| (*)
418|/\@<!|	\@<!	\@<!	nothing, requires NO match behind |/zero-width| (*)
419
420(*) {not in Vi}
421
422
423Overview of ordinary atoms.				*/ordinary-atom*
424More explanation and examples below, follow the links.
425
426      ordinary atom ~
427      magic   nomagic	matches ~
428|/^|	^	^	start-of-line (at start of pattern) |/zero-width|
429|/\^|	\^	\^	literal '^'
430|/\_^|	\_^	\_^	start-of-line (used anywhere) |/zero-width|
431|/$|	$	$	end-of-line (at end of pattern) |/zero-width|
432|/\$|	\$	\$	literal '$'
433|/\_$|	\_$	\_$	end-of-line (used anywhere) |/zero-width|
434|/.|	.	\.	any single character (not an end-of-line)
435|/\_.|	\_.	\_.	any single character or end-of-line
436|/\<|	\<	\<	beginning of a word |/zero-width|
437|/\>|	\>	\>	end of a word |/zero-width|
438|/\zs|	\zs	\zs	anything, sets start of match
439|/\ze|	\ze	\ze	anything, sets end of match
440|/\%^|	\%^	\%^	beginning of file |/zero-width|		*E71*
441|/\%$|	\%$	\%$	end of file |/zero-width|
442|/\%V|	\%V	\%V	inside Visual area |/zero-width|
443|/\%#|	\%#	\%#	cursor position |/zero-width|
444|/\%'m|	\%'m	\%'m	mark m position |/zero-width|
445|/\%l|	\%23l	\%23l	in line 23 |/zero-width|
446|/\%c|	\%23c	\%23c	in column 23 |/zero-width|
447|/\%v|	\%23v	\%23v	in virtual column 23 |/zero-width|
448
449Character classes {not in Vi}:				*/character-classes*
450|/\i|	\i	\i	identifier character (see 'isident' option)
451|/\I|	\I	\I	like "\i", but excluding digits
452|/\k|	\k	\k	keyword character (see 'iskeyword' option)
453|/\K|	\K	\K	like "\k", but excluding digits
454|/\f|	\f	\f	file name character (see 'isfname' option)
455|/\F|	\F	\F	like "\f", but excluding digits
456|/\p|	\p	\p	printable character (see 'isprint' option)
457|/\P|	\P	\P	like "\p", but excluding digits
458|/\s|	\s	\s	whitespace character: <Space> and <Tab>
459|/\S|	\S	\S	non-whitespace character; opposite of \s
460|/\d|	\d	\d	digit:				[0-9]
461|/\D|	\D	\D	non-digit:			[^0-9]
462|/\x|	\x	\x	hex digit:			[0-9A-Fa-f]
463|/\X|	\X	\X	non-hex digit:			[^0-9A-Fa-f]
464|/\o|	\o	\o	octal digit:			[0-7]
465|/\O|	\O	\O	non-octal digit:		[^0-7]
466|/\w|	\w	\w	word character:			[0-9A-Za-z_]
467|/\W|	\W	\W	non-word character:		[^0-9A-Za-z_]
468|/\h|	\h	\h	head of word character:		[A-Za-z_]
469|/\H|	\H	\H	non-head of word character:	[^A-Za-z_]
470|/\a|	\a	\a	alphabetic character:		[A-Za-z]
471|/\A|	\A	\A	non-alphabetic character:	[^A-Za-z]
472|/\l|	\l	\l	lowercase character:		[a-z]
473|/\L|	\L	\L	non-lowercase character:	[^a-z]
474|/\u|	\u	\u	uppercase character:		[A-Z]
475|/\U|	\U	\U	non-uppercase character		[^A-Z]
476|/\_|	\_x	\_x	where x is any of the characters above: character
477			class with end-of-line included
478(end of character classes)
479
480|/\e|	\e	\e	<Esc>
481|/\t|	\t	\t	<Tab>
482|/\r|	\r	\r	<CR>
483|/\b|	\b	\b	<BS>
484|/\n|	\n	\n	end-of-line
485|/~|	~	\~	last given substitute string
486|/\1|	\1	\1	same string as matched by first \(\) {not in Vi}
487|/\2|	\2	\2	Like "\1", but uses second \(\)
488	   ...
489|/\9|	\9	\9	Like "\1", but uses ninth \(\)
490								*E68*
491|/\z1|	\z1	\z1	only for syntax highlighting, see |:syn-ext-match|
492	   ...
493|/\z1|	\z9	\z9	only for syntax highlighting, see |:syn-ext-match|
494
495	x	x	a character with no special meaning matches itself
496
497|/[]|	[]	\[]	any character specified inside the []
498|/\%[]| \%[]	\%[]	a sequence of optionally matched atoms
499
500|/\c|	\c	\c	ignore case
501|/\C|	\C	\C	match case
502|/\m|	\m	\m	'magic' on for the following chars in the pattern
503|/\M|	\M	\M	'magic' off for the following chars in the pattern
504|/\v|	\v	\v	the following chars in the pattern are "very magic"
505|/\V|	\V	\V	the following chars in the pattern are "very nomagic"
506|/\Z|	\Z	\Z	ignore differences in Unicode "combining characters".
507			Useful when searching voweled Hebrew or Arabic text.
508
509|/\%d|	\%d	\%d	match specified decimal character (eg \%d123
510|/\%x|	\%x	\%x	match specified hex character (eg \%x2a)
511|/\%o|	\%o	\%o	match specified octal character (eg \%o040)
512|/\%u|	\%u	\%u	match specified multibyte character (eg \%u20ac)
513|/\%U|	\%U	\%U	match specified large multibyte character (eg
514			\%U12345678)
515
516Example			matches ~
517\<\I\i*		or
518\<\h\w*
519\<[a-zA-Z_][a-zA-Z0-9_]*
520			An identifier (e.g., in a C program).
521
522\(\.$\|\. \)		A period followed by <EOL> or a space.
523
524[.!?][])"']*\($\|[ ]\)	A search pattern that finds the end of a sentence,
525			with almost the same definition as the ")" command.
526
527cat\Z			Both "cat" and "càt" ("a" followed by 0x0300)
528			Does not match "càt" (character 0x00e0), even
529			though it may look the same.
530
531
532==============================================================================
5335. Multi items						*pattern-multi-items*
534
535An atom can be followed by an indication of how many times the atom can be
536matched and in what way.  This is called a multi.  See |/multi| for an
537overview.
538
539						*/star* */\star* *E56*
540*	(use \* when 'magic' is not set)
541	Matches 0 or more of the preceding atom, as many as possible.
542	Example  'nomagic'	matches ~
543	a*	   a\*		"", "a", "aa", "aaa", etc.
544	.*	   \.\*		anything, also an empty string, no end-of-line
545	\_.*	   \_.\*	everything up to the end of the buffer
546	\_.*END	   \_.\*END	everything up to and including the last "END"
547				in the buffer
548
549	Exception: When "*" is used at the start of the pattern or just after
550	"^" it matches the star character.
551
552	Be aware that repeating "\_." can match a lot of text and take a long
553	time.  For example, "\_.*END" matches all text from the current
554	position to the last occurrence of "END" in the file.  Since the "*"
555	will match as many as possible, this first skips over all lines until
556	the end of the file and then tries matching "END", backing up one
557	character at a time.
558
559							*/\+* *E57*
560\+	Matches 1 or more of the preceding atom, as many as possible. {not in
561	Vi}
562	Example		matches ~
563	^.\+$		any non-empty line
564	\s\+		white space of at least one character
565
566							*/\=*
567\=	Matches 0 or 1 of the preceding atom, as many as possible. {not in Vi}
568	Example		matches ~
569	foo\=		"fo" and "foo"
570
571							*/\?*
572\?	Just like \=.  Cannot be used when searching backwards with the "?"
573	command. {not in Vi}
574
575						*/\{* *E58* *E60* *E554*
576\{n,m}	Matches n to m of the preceding atom, as many as possible
577\{n}	Matches n of the preceding atom
578\{n,}	Matches at least n of the preceding atom, as many as possible
579\{,m}	Matches 0 to m of the preceding atom, as many as possible
580\{}	Matches 0 or more of the preceding atom, as many as possible (like *)
581							*/\{-*
582\{-n,m}	matches n to m of the preceding atom, as few as possible
583\{-n}	matches n of the preceding atom
584\{-n,}	matches at least n of the preceding atom, as few as possible
585\{-,m}	matches 0 to m of the preceding atom, as few as possible
586\{-}	matches 0 or more of the preceding atom, as few as possible
587	{Vi does not have any of these}
588
589	n and m are positive decimal numbers or zero
590								*non-greedy*
591	If a "-" appears immediately after the "{", then a shortest match
592	first algorithm is used (see example below).  In particular, "\{-}" is
593	the same as "*" but uses the shortest match first algorithm.  BUT: A
594	match that starts earlier is preferred over a shorter match: "a\{-}b"
595	matches "aaab" in "xaaab".
596
597	Example			matches ~
598	ab\{2,3}c		"abbc" or "abbbc"
599	a\{5}			"aaaaa".
600	ab\{2,}c		"abbc", "abbbc", "abbbbc", etc
601	ab\{,3}c		"ac", "abc", "abbc" or "abbbc".
602	a[bc]\{3}d		"abbbd", "abbcd", "acbcd", "acccd", etc.
603	a\(bc\)\{1,2}d		"abcd" or "abcbcd"
604	a[bc]\{-}[cd]		"abc" in "abcd"
605	a[bc]*[cd]		"abcd" in "abcd"
606
607	The } may optionally be preceded with a backslash: \{n,m\}.
608
609							*/\@=*
610\@=	Matches the preceding atom with zero width. {not in Vi}
611	Like "(?=pattern)" in Perl.
612	Example			matches ~
613	foo\(bar\)\@=		"foo" in "foobar"
614	foo\(bar\)\@=foo	nothing
615							*/zero-width*
616	When using "\@=" (or "^", "$", "\<", "\>") no characters are included
617	in the match.  These items are only used to check if a match can be
618	made.  This can be tricky, because a match with following items will
619	be done in the same position.  The last example above will not match
620	"foobarfoo", because it tries match "foo" in the same position where
621	"bar" matched.
622
623	Note that using "\&" works the same as using "\@=": "foo\&.." is the
624	same as "\(foo\)\@=..".  But using "\&" is easier, you don't need the
625	braces.
626
627
628							*/\@!*
629\@!	Matches with zero width if the preceding atom does NOT match at the
630	current position. |/zero-width| {not in Vi}
631	Like '(?!pattern)" in Perl.
632	Example			matches ~
633	foo\(bar\)\@!		any "foo" not followed by "bar"
634	a.\{-}p\@!		"a", "ap", "app", etc. not followed by a "p"
635	if \(\(then\)\@!.\)*$	"if " not followed by "then"
636
637	Using "\@!" is tricky, because there are many places where a pattern
638	does not match.  "a.*p\@!" will match from an "a" to the end of the
639	line, because ".*" can match all characters in the line and the "p"
640	doesn't match at the end of the line.  "a.\{-}p\@!" will match any
641	"a", "ap", "aap", etc. that isn't followed by a "p", because the "."
642	can match a "p" and "p\@!" doesn't match after that.
643
644	You can't use "\@!" to look for a non-match before the matching
645	position: "\(foo\)\@!bar" will match "bar" in "foobar", because at the
646	position where "bar" matches, "foo" does not match.  To avoid matching
647	"foobar" you could use "\(foo\)\@!...bar", but that doesn't match a
648	bar at the start of a line.  Use "\(foo\)\@<!bar".
649
650							*/\@<=*
651\@<=	Matches with zero width if the preceding atom matches just before what
652	follows. |/zero-width| {not in Vi}
653	Like '(?<=pattern)" in Perl, but Vim allows non-fixed-width patterns.
654	Example			matches ~
655	\(an\_s\+\)\@<=file	"file" after "an" and white space or an
656				end-of-line
657	For speed it's often much better to avoid this multi.  Try using "\zs"
658	instead |/\zs|.  To match the same as the above example:
659		an\_s\+\zsfile
660
661	"\@<=" and "\@<!" check for matches just before what follows.
662	Theoretically these matches could start anywhere before this position.
663	But to limit the time needed, only the line where what follows matches
664	is searched, and one line before that (if there is one).  This should
665	be sufficient to match most things and not be too slow.
666	The part of the pattern after "\@<=" and "\@<!" are checked for a
667	match first, thus things like "\1" don't work to reference \(\) inside
668	the preceding atom.  It does work the other way around:
669	Example			matches ~
670	\1\@<=,\([a-z]\+\)	",abc" in "abc,abc"
671
672							*/\@<!*
673\@<!	Matches with zero width if the preceding atom does NOT match just
674	before what follows.  Thus this matches if there is no position in the
675	current or previous line where the atom matches such that it ends just
676	before what follows.  |/zero-width| {not in Vi}
677	Like '(?<!pattern)" in Perl, but Vim allows non-fixed-width patterns.
678	The match with the preceding atom is made to end just before the match
679	with what follows, thus an atom that ends in ".*" will work.
680	Warning: This can be slow (because many positions need to be checked
681	for a match).
682	Example			matches ~
683	\(foo\)\@<!bar		any "bar" that's not in "foobar"
684	\(\/\/.*\)\@\<!in	"in" which is not after "//"
685
686							*/\@>*
687\@>	Matches the preceding atom like matching a whole pattern. {not in Vi}
688	Like '(?>pattern)" in Perl.
689	Example		matches ~
690	\(a*\)\@>a	nothing (the "a*" takes all the "a"'s, there can't be
691			another one following)
692
693	This matches the preceding atom as if it was a pattern by itself.  If
694	it doesn't match, there is no retry with shorter sub-matches or
695	anything.  Observe this difference: "a*b" and "a*ab" both match
696	"aaab", but in the second case the "a*" matches only the first two
697	"a"s.  "\(a*\)\@>ab" will not match "aaab", because the "a*" matches
698	the "aaa" (as many "a"s as possible), thus the "ab" can't match.
699
700
701==============================================================================
7026.  Ordinary atoms					*pattern-atoms*
703
704An ordinary atom can be:
705
706							*/^*
707^	At beginning of pattern or after "\|", "\(", "\%(" or "\n": matches
708	start-of-line; at other positions, matches literal '^'. |/zero-width|
709	Example		matches ~
710	^beep(		the start of the C function "beep" (probably).
711
712							*/\^*
713\^	Matches literal '^'.  Can be used at any position in the pattern.
714
715							*/\_^*
716\_^	Matches start-of-line. |/zero-width|  Can be used at any position in
717	the pattern.
718	Example		matches ~
719	\_s*\_^foo	white space and blank lines and then "foo" at
720			start-of-line
721
722							*/$*
723$	At end of pattern or in front of "\|" or "\)" ("|" or ")" after "\v"):
724	matches end-of-line <EOL>; at other positions, matches literal '$'.
725	|/zero-width|
726
727							*/\$*
728\$	Matches literal '$'.  Can be used at any position in the pattern.
729
730							*/\_$*
731\_$	Matches end-of-line. |/zero-width|  Can be used at any position in the
732	pattern.  Note that "a\_$b" never matches, since "b" cannot match an
733	end-of-line.  Use "a\nb" instead |/\n|.
734	Example		matches ~
735	foo\_$\_s*	"foo" at end-of-line and following white space and
736			blank lines
737
738.	(with 'nomagic': \.)				*/.* */\.*
739	Matches any single character, but not an end-of-line.
740
741							*/\_.*
742\_.	Matches any single character or end-of-line.
743	Careful: "\_.*" matches all text to the end of the buffer!
744
745							*/\<*
746\<	Matches the beginning of a word: The next char is the first char of a
747	word.  The 'iskeyword' option specifies what is a word character.
748	|/zero-width|
749
750							*/\>*
751\>	Matches the end of a word: The previous char is the last char of a
752	word.  The 'iskeyword' option specifies what is a word character.
753	|/zero-width|
754
755							*/\zs*
756\zs	Matches at any position, and sets the start of the match there: The
757	next char is the first char of the whole match. |/zero-width|
758	Example: >
759		/^\s*\zsif
760<	matches an "if" at the start of a line, ignoring white space.
761	Can be used multiple times, the last one encountered in a matching
762	branch is used.  Example: >
763		/\(.\{-}\zsFab\)\{3}
764<	Finds the third occurrence of "Fab".
765	{not in Vi} {not available when compiled without the +syntax feature}
766							*/\ze*
767\ze	Matches at any position, and sets the end of the match there: The
768	previous char is the last char of the whole match. |/zero-width|
769	Can be used multiple times, the last one encountered in a matching
770	branch is used.
771	Example: "end\ze\(if\|for\)" matches the "end" in "endif" and
772	"endfor".
773	{not in Vi} {not available when compiled without the +syntax feature}
774
775						*/\%^* *start-of-file*
776\%^	Matches start of the file.  When matching with a string, matches the
777	start of the string. {not in Vi}
778	For example, to find the first "VIM" in a file: >
779		/\%^\_.\{-}\zsVIM
780<
781						*/\%$* *end-of-file*
782\%$	Matches end of the file.  When matching with a string, matches the
783	end of the string. {not in Vi}
784	Note that this does NOT find the last "VIM" in a file: >
785		/VIM\_.\{-}\%$
786<	It will find the next VIM, because the part after it will always
787	match.  This one will find the last "VIM" in the file: >
788		/VIM\ze\(\(VIM\)\@!\_.\)*\%$
789<	This uses |/\@!| to ascertain that "VIM" does NOT match in any
790	position after the first "VIM".
791	Searching from the end of the file backwards is easier!
792
793						*/\%V*
794\%V	Match inside the Visual area.  When Visual mode has already been
795	stopped match in the area that |gv| would reselect.
796	Only works for the current buffer.
797
798						*/\%#* *cursor-position*
799\%#	Matches with the cursor position.  Only works when matching in a
800	buffer displayed in a window. {not in Vi}
801	WARNING: When the cursor is moved after the pattern was used, the
802	result becomes invalid.  Vim doesn't automatically update the matches.
803	This is especially relevant for syntax highlighting and 'hlsearch'.
804	In other words: When the cursor moves the display isn't updated for
805	this change.  An update is done for lines which are changed (the whole
806	line is updated) or when using the |CTRL-L| command (the whole screen
807	is updated).  Example, to highlight the word under the cursor: >
808		/\k*\%#\k*
809<	When 'hlsearch' is set and you move the cursor around and make changes
810	this will clearly show when the match is updated or not.
811
812						*/\%'m* */\%<'m* */\%>'m*
813\%'m	Matches with the position of mark m.
814\%<'m	Matches before the position of mark m.
815\%>'m	Matches after the position of mark m.
816	Example, to highlight the text from mark 's to 'e: >
817		/.\%>'s.*\%<'e..
818<	Note that two dots are required to include mark 'e in the match.  That
819	is because "\%<'e" matches at the character before the 'e mark, and
820	since it's a |/zero-width| match it doesn't include that character.
821	{not in Vi}
822	WARNING: When the mark is moved after the pattern was used, the result
823	becomes invalid.  Vim doesn't automatically update the matches.
824	Similar to moving the cursor for "\%#" |/\%#|.
825
826						*/\%l* */\%>l* */\%<l*
827\%23l	Matches in a specific line.
828\%<23l	Matches above a specific line (lower line number).
829\%>23l	Matches below a specific line (higher line number).
830	These three can be used to match specific lines in a buffer.  The "23"
831	can be any line number.  The first line is 1. {not in Vi}
832	WARNING: When inserting or deleting lines Vim does not automatically
833	update the matches.  This means Syntax highlighting quickly becomes
834	wrong.
835	Example, to highlight the line where the cursor currently is: >
836		:exe '/\%' . line(".") . 'l.*'
837<	When 'hlsearch' is set and you move the cursor around and make changes
838	this will clearly show when the match is updated or not.
839
840						*/\%c* */\%>c* */\%<c*
841\%23c	Matches in a specific column.
842\%<23c	Matches before a specific column.
843\%>23c	Matches after a specific column.
844	These three can be used to match specific columns in a buffer or
845	string.  The "23" can be any column number.  The first column is 1.
846	Actually, the column is the byte number (thus it's not exactly right
847	for multi-byte characters).  {not in Vi}
848	WARNING: When inserting or deleting text Vim does not automatically
849	update the matches.  This means Syntax highlighting quickly becomes
850	wrong.
851	Example, to highlight the column where the cursor currently is: >
852		:exe '/\%' . col(".") . 'c'
853<	When 'hlsearch' is set and you move the cursor around and make changes
854	this will clearly show when the match is updated or not.
855	Example for matching a single byte in column 44: >
856		/\%>43c.\%<46c
857<	Note that "\%<46c" matches in column 45 when the "." matches a byte in
858	column 44.
859						*/\%v* */\%>v* */\%<v*
860\%23v	Matches in a specific virtual column.
861\%<23v	Matches before a specific virtual column.
862\%>23v	Matches after a specific virtual column.
863	These three can be used to match specific virtual columns in a buffer
864	or string.  When not matching with a buffer in a window, the option
865	values of the current window are used (e.g., 'tabstop').
866	The "23" can be any column number.  The first column is 1.
867	Note that some virtual column positions will never match, because they
868	are halfway a Tab or other character that occupies more than one
869	screen character.  {not in Vi}
870	WARNING: When inserting or deleting text Vim does not automatically
871	update highlighted matches.  This means Syntax highlighting quickly
872	becomes wrong.
873	Example, to highlight the all characters after virtual column 72: >
874		/\%>72v.*
875<	When 'hlsearch' is set and you move the cursor around and make changes
876	this will clearly show when the match is updated or not.
877	To match the text up to column 17: >
878		/.*\%17v
879<	Column 17 is not included, because that's where the "\%17v" matches,
880	and since this is a |/zero-width| match, column 17 isn't included in
881	the match.  This does the same: >
882		/.*\%<18v
883<
884
885Character classes: {not in Vi}
886\i	identifier character (see 'isident' option)	*/\i*
887\I	like "\i", but excluding digits			*/\I*
888\k	keyword character (see 'iskeyword' option)	*/\k*
889\K	like "\k", but excluding digits			*/\K*
890\f	file name character (see 'isfname' option)	*/\f*
891\F	like "\f", but excluding digits			*/\F*
892\p	printable character (see 'isprint' option)	*/\p*
893\P	like "\p", but excluding digits			*/\P*
894
895NOTE: the above also work for multi-byte characters.  The ones below only
896match ASCII characters, as indicated by the range.
897
898						*whitespace* *white-space*
899\s	whitespace character: <Space> and <Tab>		*/\s*
900\S	non-whitespace character; opposite of \s	*/\S*
901\d	digit:				[0-9]		*/\d*
902\D	non-digit:			[^0-9]		*/\D*
903\x	hex digit:			[0-9A-Fa-f]	*/\x*
904\X	non-hex digit:			[^0-9A-Fa-f]	*/\X*
905\o	octal digit:			[0-7]		*/\o*
906\O	non-octal digit:		[^0-7]		*/\O*
907\w	word character:			[0-9A-Za-z_]	*/\w*
908\W	non-word character:		[^0-9A-Za-z_]	*/\W*
909\h	head of word character:		[A-Za-z_]	*/\h*
910\H	non-head of word character:	[^A-Za-z_]	*/\H*
911\a	alphabetic character:		[A-Za-z]	*/\a*
912\A	non-alphabetic character:	[^A-Za-z]	*/\A*
913\l	lowercase character:		[a-z]		*/\l*
914\L	non-lowercase character:	[^a-z]		*/\L*
915\u	uppercase character:		[A-Z]		*/\u*
916\U	non-uppercase character		[^A-Z]		*/\U*
917
918	NOTE: Using the atom is faster than the [] form.
919
920	NOTE: 'ignorecase', "\c" and "\C" are not used by character classes.
921
922			*/\_* *E63* */\_i* */\_I* */\_k* */\_K* */\_f* */\_F*
923			*/\_p* */\_P* */\_s* */\_S* */\_d* */\_D* */\_x* */\_X*
924			*/\_o* */\_O* */\_w* */\_W* */\_h* */\_H* */\_a* */\_A*
925			*/\_l* */\_L* */\_u* */\_U*
926\_x	Where "x" is any of the characters above: The character class with
927	end-of-line added
928(end of character classes)
929
930\e	matches <Esc>					*/\e*
931\t	matches <Tab>					*/\t*
932\r	matches <CR>					*/\r*
933\b	matches <BS>					*/\b*
934\n	matches an end-of-line				*/\n*
935	When matching in a string instead of buffer text a literal newline
936	character is matched.
937
938~	matches the last given substitute string	*/~* */\~*
939
940\(\)	A pattern enclosed by escaped parentheses.	*/\(* */\(\)* */\)*
941	E.g., "\(^a\)" matches 'a' at the start of a line.  *E51* *E54* *E55*
942
943\1      Matches the same string that was matched by	*/\1* *E65*
944	the first sub-expression in \( and \). {not in Vi}
945	Example: "\([a-z]\).\1" matches "ata", "ehe", "tot", etc.
946\2      Like "\1", but uses second sub-expression,	*/\2*
947   ...							*/\3*
948\9      Like "\1", but uses ninth sub-expression.	*/\9*
949	Note: The numbering of groups is done based on which "\(" comes first
950	in the pattern (going left to right), NOT based on what is matched
951	first.
952
953\%(\)	A pattern enclosed by escaped parentheses.	*/\%(\)* */\%(* *E53*
954	Just like \(\), but without counting it as a sub-expression.  This
955	allows using more groups and it's a little bit faster.
956	{not in Vi}
957
958x	A single character, with no special meaning, matches itself
959
960							*/\* */\\*
961\x	A backslash followed by a single character, with no special meaning,
962	is reserved for future expansions
963
964[]	(with 'nomagic': \[])		*/[]* */\[]* */\_[]* */collection*
965\_[]
966	A collection.  This is a sequence of characters enclosed in brackets.
967	It matches any single character in the collection.
968	Example		matches ~
969	[xyz]		any 'x', 'y' or 'z'
970	[a-zA-Z]$	any alphabetic character at the end of a line
971	\c[a-z]$	same
972								*/[\n]*
973	With "\_" prepended the collection also includes the end-of-line.
974	The same can be done by including "\n" in the collection.  The
975	end-of-line is also matched when the collection starts with "^"!  Thus
976	"\_[^ab]" matches the end-of-line and any character but "a" and "b".
977	This makes it Vi compatible: Without the "\_" or "\n" the collection
978	does not match an end-of-line.
979								*E769*
980	When the ']' is not there Vim will not give an error message but
981	assume no collection is used.  Useful to search for '['.  However, you
982	do get E769 for internal searching.
983
984	If the sequence begins with "^", it matches any single character NOT
985	in the collection: "[^xyz]" matches anything but 'x', 'y' and 'z'.
986	- If two characters in the sequence are separated by '-', this is
987	  shorthand for the full list of ASCII characters between them.  E.g.,
988	  "[0-9]" matches any decimal digit.
989	- A character class expression is evaluated to the set of characters
990	  belonging to that character class.  The following character classes
991	  are supported:
992			  Name		Contents ~
993*[:alnum:]*		  [:alnum:]     letters and digits
994*[:alpha:]*		  [:alpha:]     letters
995*[:blank:]*		  [:blank:]     space and tab characters
996*[:cntrl:]*		  [:cntrl:]     control characters
997*[:digit:]*		  [:digit:]     decimal digits
998*[:graph:]*		  [:graph:]     printable characters excluding space
999*[:lower:]*		  [:lower:]     lowercase letters (all letters when
1000					'ignorecase' is used)
1001*[:print:]*		  [:print:]     printable characters including space
1002*[:punct:]*		  [:punct:]     punctuation characters
1003*[:space:]*		  [:space:]     whitespace characters
1004*[:upper:]*		  [:upper:]     uppercase letters (all letters when
1005					'ignorecase' is used)
1006*[:xdigit:]*		  [:xdigit:]    hexadecimal digits
1007*[:return:]*		  [:return:]	the <CR> character
1008*[:tab:]*		  [:tab:]	the <Tab> character
1009*[:escape:]*		  [:escape:]	the <Esc> character
1010*[:backspace:]*		  [:backspace:]	the <BS> character
1011	  The brackets in character class expressions are additional to the
1012	  brackets delimiting a collection.  For example, the following is a
1013	  plausible pattern for a UNIX filename: "[-./[:alnum:]_~]\+" That is,
1014	  a list of at least one character, each of which is either '-', '.',
1015	  '/', alphabetic, numeric, '_' or '~'.
1016	  These items only work for 8-bit characters.
1017							*/[[=* *[==]*
1018	- An equivalence class.  This means that characters are matched that
1019	  have almost the same meaning, e.g., when ignoring accents.  The form
1020	  is:
1021		[=a=]
1022	  Currently this is only implemented for latin1.  Also works for the
1023	  latin1 characters in utf-8 and latin9.
1024							*/[[.* *[..]*
1025	- A collation element.  This currently simply accepts a single
1026	  character in the form:
1027		[.a.]
1028							  */\]*
1029	- To include a literal ']', '^', '-' or '\' in the collection, put a
1030	  backslash before it: "[xyz\]]", "[\^xyz]", "[xy\-z]" and "[xyz\\]".
1031	  (Note: POSIX does not support the use of a backslash this way).  For
1032	  ']' you can also make it the first character (following a possible
1033	  "^"):  "[]xyz]" or "[^]xyz]" {not in Vi}.
1034	  For '-' you can also make it the first or last character: "[-xyz]",
1035	  "[^-xyz]" or "[xyz-]".  For '\' you can also let it be followed by
1036	  any character that's not in "^]-\bertn".  "[\xyz]" matches '\', 'x',
1037	  'y' and 'z'.  It's better to use "\\" though, future expansions may
1038	  use other characters after '\'.
1039	- The following translations are accepted when the 'l' flag is not
1040	  included in 'cpoptions' {not in Vi}:
1041		\e	<Esc>
1042		\t	<Tab>
1043		\r	<CR>	(NOT end-of-line!)
1044		\b	<BS>
1045		\n	line break, see above |/[\n]|
1046		\d123	decimal number of character
1047		\o40	octal number of character up to 0377
1048		\x20	hexadecimal number of character up to 0xff
1049		\u20AC	hex. number of multibyte character up to 0xffff
1050		\U1234	hex. number of multibyte character up to 0xffffffff
1051	  NOTE: The other backslash codes mentioned above do not work inside
1052	  []!
1053	- Matching with a collection can be slow, because each character in
1054	  the text has to be compared with each character in the collection.
1055	  Use one of the other atoms above when possible.  Example: "\d" is
1056	  much faster than "[0-9]" and matches the same characters.
1057
1058						*/\%[]* *E69* *E70* *E369*
1059\%[]	A sequence of optionally matched atoms.  This always matches.
1060	It matches as much of the list of atoms it contains as possible.  Thus
1061	it stops at the first atom that doesn't match.  For example: >
1062		/r\%[ead]
1063<	matches "r", "re", "rea" or "read".  The longest that matches is used.
1064	To match the Ex command "function", where "fu" is required and
1065	"nction" is optional, this would work: >
1066		/\<fu\%[nction]\>
1067<	The end-of-word atom "\>" is used to avoid matching "fu" in "full".
1068	It gets more complicated when the atoms are not ordinary characters.
1069	You don't often have to use it, but it is possible.  Example: >
1070		/\<r\%[[eo]ad]\>
1071<	Matches the words "r", "re", "ro", "rea", "roa", "read" and "road".
1072	There can be no \(\), \%(\) or \z(\) items inside the [] and \%[] does
1073	not nest.
1074	{not available when compiled without the +syntax feature}
1075
1076				*/\%d* */\%x* */\%o* */\%u* */\%U* *E678*
1077
1078\%d123	Matches the character specified with a decimal number.  Must be
1079	followed by a non-digit.
1080\%o40	Matches the character specified with an octal number up to 0377.
1081	Numbers below 040 must be followed by a non-octal digit or a non-digit.
1082\%x2a	Matches the character specified with up to two hexadecimal characters.
1083\%u20AC	Matches the character specified with up to four hexadecimal
1084	characters.
1085\%U1234abcd	Matches the character specified with up to eight hexadecimal
1086	characters.
1087
1088==============================================================================
10897. Ignoring case in a pattern					*/ignorecase*
1090
1091If the 'ignorecase' option is on, the case of normal letters is ignored.
1092'smartcase' can be set to ignore case when the pattern contains lowercase
1093letters only.
1094							*/\c* */\C*
1095When "\c" appears anywhere in the pattern, the whole pattern is handled like
1096'ignorecase' is on.  The actual value of 'ignorecase' and 'smartcase' is
1097ignored.  "\C" does the opposite: Force matching case for the whole pattern.
1098{only Vim supports \c and \C}
1099Note that 'ignorecase', "\c" and "\C" are not used for the character classes.
1100
1101Examples:
1102      pattern	'ignorecase'  'smartcase'	matches ~
1103	foo	  off		-		foo
1104	foo	  on		-		foo Foo FOO
1105	Foo	  on		off		foo Foo FOO
1106	Foo	  on		on		    Foo
1107	\cfoo	  -		-		foo Foo FOO
1108	foo\C	  -		-		foo
1109
1110Technical detail:				*NL-used-for-Nul*
1111<Nul> characters in the file are stored as <NL> in memory.  In the display
1112they are shown as "^@".  The translation is done when reading and writing
1113files.  To match a <Nul> with a search pattern you can just enter CTRL-@ or
1114"CTRL-V 000".  This is probably just what you expect.  Internally the
1115character is replaced with a <NL> in the search pattern.  What is unusual is
1116that typing CTRL-V CTRL-J also inserts a <NL>, thus also searches for a <Nul>
1117in the file.  {Vi cannot handle <Nul> characters in the file at all}
1118
1119						*CR-used-for-NL*
1120When 'fileformat' is "mac", <NL> characters in the file are stored as <CR>
1121characters internally.  In the display they are shown as "^M".  Otherwise this
1122works similar to the usage of <NL> for a <Nul>.
1123
1124When working with expression evaluation, a <NL> character in the pattern
1125matches a <NL> in the string.  The use of "\n" (backslash n) to match a <NL>
1126doesn't work there, it only works to match text in the buffer.
1127
1128						*pattern-multi-byte*
1129Patterns will also work with multi-byte characters, mostly as you would
1130expect.  But invalid bytes may cause trouble, a pattern with an invalid byte
1131will probably never match.
1132
1133==============================================================================
11348. Composing characters					*patterns-composing*
1135
1136							*/\Z*
1137When "\Z" appears anywhere in the pattern, composing characters are ignored.
1138Thus only the base characters need to match, the composing characters may be
1139different and the number of composing characters may differ.  Only relevant
1140when 'encoding' is "utf-8".
1141
1142When a composing character appears at the start of the pattern of after an
1143item that doesn't include the composing character, a match is found at any
1144character that includes this composing character.
1145
1146When using a dot and a composing character, this works the same as the
1147composing character by itself, except that it doesn't matter what comes before
1148this.
1149
1150The order of composing characters matters, even though changing the order
1151doesn't change what a character looks like.  This may change in the future.
1152
1153==============================================================================
11549. Compare with Perl patterns				*perl-patterns*
1155
1156Vim's regexes are most similar to Perl's, in terms of what you can do.  The
1157difference between them is mostly just notation;  here's a summary of where
1158they differ:
1159
1160Capability			in Vimspeak	in Perlspeak ~
1161----------------------------------------------------------------
1162force case insensitivity	\c		(?i)
1163force case sensitivity		\C		(?-i)
1164backref-less grouping		\%(atom\)	(?:atom)
1165conservative quantifiers	\{-n,m}		*?, +?, ??, {}?
11660-width match			atom\@=		(?=atom)
11670-width non-match		atom\@!		(?!atom)
11680-width preceding match		atom\@<=	(?<=atom)
11690-width preceding non-match	atom\@<!	(?<!atom)
1170match without retry		atom\@>		(?>atom)
1171
1172Vim and Perl handle newline characters inside a string a bit differently:
1173
1174In Perl, ^ and $ only match at the very beginning and end of the text,
1175by default, but you can set the 'm' flag, which lets them match at
1176embedded newlines as well.  You can also set the 's' flag, which causes
1177a . to match newlines as well.  (Both these flags can be changed inside
1178a pattern using the same syntax used for the i flag above, BTW.)
1179
1180On the other hand, Vim's ^ and $ always match at embedded newlines, and
1181you get two separate atoms, \%^ and \%$, which only match at the very
1182start and end of the text, respectively.  Vim solves the second problem
1183by giving you the \_ "modifier":  put it in front of a . or a character
1184class, and they will match newlines as well.
1185
1186Finally, these constructs are unique to Perl:
1187- execution of arbitrary code in the regex:  (?{perl code})
1188- conditional expressions:  (?(condition)true-expr|false-expr)
1189
1190...and these are unique to Vim:
1191- changing the magic-ness of a pattern:  \v \V \m \M
1192   (very useful for avoiding backslashitis)
1193- sequence of optionally matching atoms:  \%[atoms]
1194- \& (which is to \| what "and" is to "or";  it forces several branches
1195   to match at one spot)
1196- matching lines/columns by number:  \%5l \%5c \%5v
1197- setting the start and end of the match:  \zs \ze
1198
1199==============================================================================
120010. Highlighting matches				*match-highlight*
1201
1202							*:mat* *:match*
1203:mat[ch] {group} /{pattern}/
1204		Define a pattern to highlight in the current window.  It will
1205		be highlighted with {group}.  Example: >
1206			:highlight MyGroup ctermbg=green guibg=green
1207			:match MyGroup /TODO/
1208<		Instead of // any character can be used to mark the start and
1209		end of the {pattern}.  Watch out for using special characters,
1210		such as '"' and '|'.
1211
1212		{group} must exist at the moment this command is executed.
1213
1214		The {group} highlighting still applies when a character is
1215		to be highlighted for 'hlsearch'.
1216
1217		Note that highlighting the last used search pattern with
1218		'hlsearch' is used in all windows, while the pattern defined
1219		with ":match" only exists in the current window.  It is kept
1220		when switching to another buffer.
1221
1222		'ignorecase' does not apply, use |/\c| in the pattern to
1223		ignore case.  Otherwise case is not ignored.
1224
1225		When matching end-of-line and Vim redraws only part of the
1226		display you may get unexpected results.  That is because Vim
1227		looks for a match in the line where redrawing starts.
1228
1229		Also see |matcharg()|, it returns the highlight group and
1230		pattern of a previous :match command.
1231
1232		Another example, which highlights all characters in virtual
1233		column 72 and more: >
1234			:highlight rightMargin term=bold ctermfg=blue guifg=blue
1235			:match rightMargin /.\%>72v/
1236<		To highlight all character that are in virtual column 7: >
1237			:highlight col8 ctermbg=grey guibg=grey
1238			:match col8 /\%<8v.\%>7v/
1239<		Note the use of two items to also match a character that
1240		occupies more than one virtual column, such as a TAB.
1241
1242:mat[ch]
1243:mat[ch] none
1244		Clear a previously defined match pattern.
1245
1246
1247:2mat[ch] {group} /{pattern}/					*:2match*
1248:2mat[ch]
1249:2mat[ch] none
1250:3mat[ch] {group} /{pattern}/					*:3match*
1251:3mat[ch]
1252:3mat[ch] none
1253		Just like |:match| above, but set a separate match.  Thus
1254		there can be three matches active at the same time.  The match
1255		with the lowest number has priority if several match at the
1256		same position.
1257		The ":3match" command is used by the |matchparen| plugin.  You
1258		are suggested to use ":match" for manual matching and
1259		":2match" for another plugin.
1260
1261
1262 vim:tw=78:ts=8:ft=help:norl:
1263