Vim documentation: pattern

 *pattern.txt* For Vim version 7.3. Last change: 2011 Feb 25 VIM REFERENCE MANUAL by Bram Moolenaar Patterns and search commands	*pattern-searches* The very basics can be found in section |03.9| of the user manual. A few more explanations are in chapter 27 |usr_27.txt|. 1. Search commands	|search-commands| 2. The definition of a pattern	|search-pattern| 3. Magic	|/magic| 4. Overview of pattern items	|pattern-overview| 5. Multi items	|pattern-multi-items| 6. Ordinary atoms	|pattern-atoms| 7. Ignoring case in a pattern|/ignorecase| 8. Composing characters	|patterns-composing| 9. Compare with Perl patterns	|perl-patterns| 10. Highlighting matches	|match-highlight| ============================================================================== 1. Search commands	*search-commands* *E486*	*/* /{pattern}[/]<CR>	Search forward for the [count]'th occurrence of	{pattern} |exclusive|. /{pattern}/{offset}<CR>	Search forward for the [count]'th occurrence of	{pattern} and go |{offset}| lines up or down.	|linewise|.	*/<CR>* /<CR>Search forward for the [count]'th occurrence of the	latest used pattern |last-pattern| with latest used	|{offset}|. //{offset}<CR>	Search forward for the [count]'th occurrence of the	latest used pattern |last-pattern| with new	|{offset}|. If {offset} is empty no offset is used.	*?* ?{pattern}[?]<CR>	Search backward for the [count]'th previous	occurrence of {pattern} |exclusive|. ?{pattern}?{offset}<CR>	Search backward for the [count]'th previous	occurrence of {pattern} and go |{offset}| lines up or	down |linewise|.	*?<CR>* ?<CR>Search backward for the [count]'th occurrence of the	latest used pattern |last-pattern| with latest used	|{offset}|. ??{offset}<CR>	Search backward for the [count]'th occurrence of the	latest used pattern |last-pattern| with new	|{offset}|. If {offset} is empty no offset is used.	*n* nRepeat the latest "/" or "?" [count] times.	|last-pattern| {Vi: no count}	*N* N	Repeat the latest "/" or "?" [count] times in	opposite direction. |last-pattern| {Vi: no count}	*star* *E348* *E349* *	Search forward for the [count]'th occurrence of the word nearest to the cursor. The word used for the	search is the first of:	1. the keyword under the cursor |'iskeyword'|	2. the first keyword after the cursor, in the current line	3. the non-blank word under the cursor	4. the first non-blank word after the cursor, in the current line	Only whole keywords are searched for, like with the	command "/\<keyword\>". |exclusive| {not in Vi} 'ignorecase' is used, 'smartcase' is not.	*#* #	Same as "*", but search backward. The pound sign	(character 163) also works. If the "#" key works as	backspace, try using "stty erase <BS>" before starting	Vim (<BS> is CTRL-H or a real backspace). {not in Vi}	*gstar* g*	Like "*", but don't put "\<" and "\>" around the word.	This makes the search also find matches that are not a	whole word. {not in Vi}	*g#* g#Like "#", but don't put "\<" and "\>" around the word.	This makes the search also find matches that are not a	whole word. {not in Vi}	*gd* gdGoto local Declaration. When the cursor is on a local	variable, this command will jump to its declaration.	First Vim searches for the start of the current	function, just like "[[". If it is not found the	search stops in line 1. If it is found, Vim goes back	until a blank line is found. From this position Vim	searches for the keyword under the cursor, like with	"*", but lines that look like a comment are ignored	(see 'comments' option).	Note that this is not guaranteed to work, Vim does not	really check the syntax, it only searches for a match	with the keyword. If included files also need to be	searched use the commands listed in |include-search|.	After this command |n| searches forward for the next	match (not backward).	{not in Vi}	*gD* gDGoto global Declaration. When the cursor is on a	global variable that is defined in the file, this	command will jump to its declaration. This works just	like "gd", except that the search for the keyword	always starts in line 1. {not in Vi}	*1gd* 1gdLike "gd", but ignore matches inside a {} block that	ends before the cursor position. {not in Vi}	*1gD* 1gDLike "gD", but ignore matches inside a {} block that	ends before the cursor position. {not in Vi}	*CTRL-C* CTRL-CInterrupt current (search) command. Use CTRL-Break on MS-DOS |dos-CTRL-Break|.	In Normal mode, any pending command is aborted.	*:noh* *:nohlsearch* :noh[lsearch]	Stop the highlighting for the 'hlsearch' option. It	is automatically turned back on when using a search	command, or setting the 'hlsearch' option.	This command doesn't work in an autocommand, because	the highlighting state is saved and restored when	executing autocommands |autocmd-searchpat|.	Same thing for when invoking a user function. While typing the search pattern the current match will be shown if the 'incsearch' option is on. Remember that you still have to finish the search command with <CR> to actually position the cursor at the displayed match. Or use <Esc> to abandon the search. All matches for the last used search pattern will be highlighted if you set the 'hlsearch' option. This can be suspended with the |:nohlsearch| command.	*search-offset* *{offset}* These commands search for the specified pattern. With "/" and "?" an additional offset may be given. There are two types of offsets: line offsets and character offsets. {the character offsets are not in Vi} The offset gives the cursor position relative to the found match: [num]	[num] lines downwards, in column 1 +[num]	[num] lines downwards, in column 1 -[num]	[num] lines upwards, in column 1 e[+num]	[num] characters to the right of the end of the match e[-num]	[num] characters to the left of the end of the match s[+num]	[num] characters to the right of the start of the match s[-num]	[num] characters to the left of the start of the match b[+num]	[num] identical to s[+num] above (mnemonic: begin) b[-num]	[num] identical to s[-num] above (mnemonic: begin) ;{pattern} perform another search, see |//;| If a '-' or '+' is given but [num] is omitted, a count of one will be used. When including an offset with 'e', the search becomes inclusive (the character the cursor lands on is included in operations). Examples: pattern	cursor position /test/+1	one line below "test", in column 1 /test/e	on the last t of "test" /test/s+2	on the 's' of "test" /test/b-3	three characters before "test" If one of these commands is used after an operator, the characters between the cursor position before and after the search is affected. However, if a line offset is given, the whole lines between the two cursor positions are affected. An example of how to search for matches with a pattern and change the match with another word: /foo<CR>	find "foo" c//e	change until end of match bar<Esc>	type replacement //<CR>	go to start of next match c//e	change until end of match beep<Esc>	type another replacement etc.	*//;* *E386* A very special offset is ';' followed by another search command. For example:  /test 1/;/test  /test.*/+1;?ing? The first one first finds the next occurrence of "test 1", and then the first occurrence of "test" after that. This is like executing two search commands after each other, except that: - It can be used as a single motion command after an operator. - The direction for a following "n" or "N" command comes from the first search command. - When an error occurs the cursor is not moved at all.	*last-pattern* The last used pattern and offset are remembered. They can be used to repeat the search, possibly in another direction or with another count. Note that two patterns are remembered: One for 'normal' search commands and one for the substitute command ":s". Each time an empty pattern is given, the previously used pattern is used. However, if there is no previous search command, a previous substitute pattern is used, if possible. The 'magic' option sticks with the last used pattern. If you change 'magic', this will not change how the last used pattern will be interpreted. The 'ignorecase' option does not do this. When 'ignorecase' is changed, it will result in the pattern to match other text. All matches for the last used search pattern will be highlighted if you set the 'hlsearch' option. To clear the last used search pattern: :let @/ = "" This will not set the pattern to an empty string, because that would match everywhere. The pattern is really cleared, like when starting Vim. The search usually skips matches that don't move the cursor. Whether the next match is found at the next character or after the skipped match depends on the 'c' flag in 'cpoptions'. See |cpo-c|. with 'c' flag: "/..." advances 1 to 3 characters	without 'c' flag: "/..." advances 1 character The unpredictability with the 'c' flag is caused by starting the search in the first column, skipping matches until one is found past the cursor position. When searching backwards, searching starts at the start of the line, using the 'c' flag in 'cpoptions' as described above. Then the last match before the cursor position is used. In Vi the ":tag" command sets the last search pattern when the tag is searched for. In Vim this is not done, the previous search pattern is still remembered, unless the 't' flag is present in 'cpoptions'. The search pattern is always put in the search history. If the 'wrapscan' option is on (which is the default), searches wrap around the end of the buffer. If 'wrapscan' is not set, the backward search stops at the beginning and the forward search stops at the end of the buffer. If 'wrapscan' is set and the pattern was not found the error message "pattern not found" is given, and the cursor will not be moved. If 'wrapscan' is not set the message becomes "search hit BOTTOM without match" when searching forward, or "search hit TOP without match" when searching backward. If wrapscan is set and the search wraps around the end of the file the message "search hit TOP, continuing at BOTTOM" or "search hit BOTTOM, continuing at TOP" is given when searching backwards or forwards respectively. This can be switched off by setting the 's' flag in the 'shortmess' option. The highlight method 'w' is used for this message (default: standout).	*search-range* You can limit the search command "/" to a certain range of lines by including \%>l items. For example, to match the word "limit" below line 199 and above line 300: /\%>199l\%<300llimit Also see |/\%>l|. Another way is to use the ":substitute" command with the 'c' flag. Example:  :.,300s/Pattern//gc This command will search from the cursor position until line 300 for "Pattern". At the match, you will be asked to type a character. Type 'q' to stop at this match, type 'n' to find the next match. The "*", "#", "g*" and "g#" commands look for a word near the cursor in this order, the first one that is found is used: - The keyword currently under the cursor. - The first keyword to the right of the cursor, in the same line. - The WORD currently under the cursor. - The first WORD to the right of the cursor, in the same line. The keyword may only contain letters and characters in 'iskeyword'. The WORD may contain any non-blanks (<Tab>s and/or <Space>s). Note that if you type with ten fingers, the characters are easy to remember: the "#" is under your left hand middle finger (search to the left and up) and the "*" is under your right hand middle finger (search to the right and down). (this depends on your keyboard layout though). ============================================================================== 2. The definition of a pattern*search-pattern* *pattern* *[pattern]*	*regular-expression* *regexp* *Pattern*	*E76* *E383* *E476* For starters, read chapter 27 of the user manual |usr_27.txt|.	*/bar* */\bar* */pattern* 1. A pattern is one or more branches, separated by "\|". It matches anything that matches one of the branches. Example: "foo\|beep" matches "foo" and matches "beep". If more than one branch matches, the first one is used. pattern ::= branch	or branch \| branch	or branch \| branch \| branch	etc.	*/branch* */\&* 2. A branch is one or more concats, separated by "\&". It matches the last concat, but only if all the preceding concats also match at the same position. Examples:	"foobeep\&..." matches "foo" in "foobeep".	".*Peter\&.*Bob" matches in a line containing both "Peter" and "Bob" branch ::= concat	or concat \& concat	or concat \& concat \& concat	etc.	*/concat* 3. A concat is one or more pieces, concatenated. It matches a match for the first piece, followed by a match for the second piece, etc. Example: "f[0-9]b", first matches "f", then a digit and then "b". concat ::= piece	or piece piece	or piece piece piece	etc.	*/piece* 4. A piece is an atom, possibly followed by a multi, an indication of how many times the atom can be matched. Example: "a*" matches any sequence of "a" characters: "", "a", "aa", etc. See |/multi|. piece ::= atom	or atom multi	*/atom* 5. An atom can be one of a long list of items. Many atoms match one character in the text. It is often an ordinary character or a character class. Braces can be used to make a pattern into an atom. The "\z(\)" construct is only for syntax highlighting. atom ::= ordinary-atom	|/ordinary-atom|	or \( pattern \)	|/\(|	or \%( pattern \)	|/\%(|	or \z( pattern \)	|/\z(| ============================================================================== 3. Magic	*/magic* Some characters in the pattern are taken literally. They match with the same character in the text. When preceded with a backslash however, these characters get a special meaning. Other characters have a special meaning without a backslash. They need to be preceded with a backslash to match literally. If a character is taken literally or not depends on the 'magic' option and the items mentioned next.	*/\m* */\M* Use of "\m" makes the pattern after it be interpreted as if 'magic' is set, ignoring the actual value of the 'magic' option. Use of "\M" makes the pattern after it be interpreted as if 'nomagic' is used.	*/\v* */\V* Use of "\v" means that in the pattern after it all ASCII characters except '0'-'9', 'a'-'z', 'A'-'Z' and '_' have a special meaning. "very magic" Use of "\V" means that in the pattern after it only the backslash has a special meaning. "very nomagic" Examples: after: \v \m \M \V	matches  'magic' 'nomagic' $ $ $ \$	matches end-of-line . . \. \.	matches any character * * \* \*	any number of the previous atom () \(\) \(\) \(\)	grouping into an atom | \| \| \|	separating alternatives \a \a \a \a	alphabetic character \\ \\ \\ \\	literal backslash \. \. . .	literal dot \{ { { {	literal '{' a a a a	literal 'a' {only Vim supports \m, \M, \v and \V} It is recommended to always keep the 'magic' option at the default setting, which is 'magic'. This avoids portability problems. To make a pattern immune to the 'magic' option being set or not, put "\m" or "\M" at the start of the pattern. ============================================================================== 4. Overview of pattern items	*pattern-overview* Overview of multi items.	*/multi* *E61* *E62* More explanation and examples below, follow the links.	*E64*  multi   'magic' 'nomagic'	matches of the preceding atom  |/star|	*	\*	0 or moreas many as possible |/\+|	\+	\+	1 or moreas many as possible (*) |/\=|	\=	\=	0 or 1as many as possible (*) |/\?|	\?	\?	0 or 1as many as possible (*) |/\{|	\{n,m}	\{n,m}n to mas many as possible (*)	\{n}	\{n}nexactly (*)	\{n,}	\{n,}	at least nas many as possible (*)	\{,m}	\{,m}	0 to mas many as possible (*)	\{}	\{}	0 or moreas many as possible (same as *) (*) |/\{-|	\{-n,m}	\{-n,m}n to mas few as possible (*)	\{-n}	\{-n}nexactly (*)	\{-n,}	\{-n,}	at least nas few as possible (*)	\{-,m}	\{-,m}	0 to mas few as possible (*)	\{-}	\{-}	0 or moreas few as possible (*)	*E59* |/\@>|	\@>	\@>	1, like matching a whole pattern (*) |/\@=|	\@=	\@=	nothing, requires a match |/zero-width| (*) |/\@!|	\@!	\@!	nothing, requires NO match |/zero-width| (*) |/\@<=|	\@<=	\@<=	nothing, requires a match behind |/zero-width| (*) |/\@<!|	\@<!	\@<!	nothing, requires NO match behind |/zero-width| (*) (*) {not in Vi} Overview of ordinary atoms.	*/ordinary-atom* More explanation and examples below, follow the links.  ordinary atom   magic nomagic	matches  |/^|	^	^	start-of-line (at start of pattern) |/zero-width| |/\^|	\^	\^	literal '^' |/\_^|	\_^	\_^	start-of-line (used anywhere) |/zero-width| |/$|	$	$	end-of-line (at end of pattern) |/zero-width| |/\$|	\$	\$	literal '$' |/\_$|	\_$	\_$	end-of-line (used anywhere) |/zero-width| |/.|	.	\.	any single character (not an end-of-line) |/\_.|	\_.	\_.	any single character or end-of-line |/\<|	\<	\<	beginning of a word |/zero-width| |/\>|	\>	\>	end of a word |/zero-width| |/\zs|	\zs	\zs	anything, sets start of match |/\ze|	\ze	\ze	anything, sets end of match |/\%^|	\%^	\%^	beginning of file |/zero-width|	*E71* |/\%$|	\%$	\%$	end of file |/zero-width| |/\%V|	\%V	\%V	inside Visual area |/zero-width| |/\%#|	\%#	\%#	cursor position |/zero-width| |/\%'m|	\%'m	\%'mmark m position |/zero-width| |/\%l|	\%23l	\%23l	in line 23 |/zero-width| |/\%c|	\%23c	\%23c	in column 23 |/zero-width| |/\%v|	\%23v	\%23v	in virtual column 23 |/zero-width| Character classes {not in Vi}:	*/character-classes* |/\i|	\i	\i	identifier character (see 'isident' option) |/\I|	\I	\I	like "\i", but excluding digits |/\k|	\k	\k	keyword character (see 'iskeyword' option) |/\K|	\K	\K	like "\k", but excluding digits |/\f|	\f	\f	file name character (see 'isfname' option) |/\F|	\F	\F	like "\f", but excluding digits |/\p|	\p	\p	printable character (see 'isprint' option) |/\P|	\P	\P	like "\p", but excluding digits |/\s|	\s	\swhitespace character: <Space> and <Tab> |/\S|	\S	\S	non-whitespace character; opposite of \s |/\d|	\d	\d	digit:	[0-9] |/\D|	\D	\D	non-digit:	[^0-9] |/\x|	\x	\x	hex digit:	[0-9A-Fa-f] |/\X|	\X	\X	non-hex digit:	[^0-9A-Fa-f] |/\o|	\o	\ooctal digit:	[0-7] |/\O|	\O	\O	non-octal digit:	[^0-7] |/\w|	\w	\wword character:	[0-9A-Za-z_] |/\W|	\W	\W	non-word character:	[^0-9A-Za-z_] |/\h|	\h	\h	head of word character:	[A-Za-z_] |/\H|	\H	\H	non-head of word character:	[^A-Za-z_] |/\a|	\a	\a	alphabetic character:	[A-Za-z] |/\A|	\A	\A	non-alphabetic character:	[^A-Za-z] |/\l|	\l	\llowercase character:	[a-z] |/\L|	\L	\L	non-lowercase character:	[^a-z] |/\u|	\u	\uuppercase character:	[A-Z] |/\U|	\U	\U	non-uppercase character	[^A-Z] |/\_|	\_x	\_x	where x is any of the characters above: character	class with end-of-line included (end of character classes) |/\e|	\e	\e<Esc> |/\t|	\t	\t<Tab> |/\r|	\r	\r<CR> |/\b|	\b	\b<BS> |/\n|	\n	\n	end-of-line |/~|	~	\~	last given substitute string |/\1|	\1	\1	same string as matched by first \(\) {not in Vi} |/\2|	\2	\2	Like "\1", but uses second \(\) ... |/\9|	\9	\9	Like "\1", but uses ninth \(\)	*E68* |/\z1|	\z1	\z1	only for syntax highlighting, see |:syn-ext-match| ... |/\z1|	\z9	\z9	only for syntax highlighting, see |:syn-ext-match| xxa character with no special meaning matches itself |/[]|	[]	\[]	any character specified inside the [] |/\%[]| \%[]	\%[]	a sequence of optionally matched atoms |/\c|	\c	\c	ignore case, do not use the 'ignorecase' option |/\C|	\C	\C	match case, do not use the 'ignorecase' option |/\m|	\m	\m'magic' on for the following chars in the pattern |/\M|	\M	\M'magic' off for the following chars in the pattern |/\v|	\v	\v	the following chars in the pattern are "very magic" |/\V|	\V	\V	the following chars in the pattern are "very nomagic" |/\Z|	\Z	\Z	ignore differences in Unicode "combining characters".	Useful when searching voweled Hebrew or Arabic text. |/\%d|	\%d	\%d	match specified decimal character (eg \%d123) |/\%x|	\%x	\%x	match specified hex character (eg \%x2a) |/\%o|	\%o	\%o	match specified octal character (eg \%o040) |/\%u|	\%u	\%u	match specified multibyte character (eg \%u20ac) |/\%U|	\%U	\%U	match specified large multibyte character (eg	\%U12345678) Example	matches  \<\I\i*	or \<\h\w* \<[a-zA-Z_][a-zA-Z0-9_]*	An identifier (e.g., in a C program). \(\.$\|\. \)	A period followed by <EOL> or a space. [.!?][])"']*\($\|[ ]\)	A search pattern that finds the end of a sentence,	with almost the same definition as the ")" command. cat\Z	Both "cat" and "càt" ("a" followed by 0x0300)	Does not match "càt" (character 0x00e0), even	though it may look the same. ============================================================================== 5. Multi items	*pattern-multi-items* An atom can be followed by an indication of how many times the atom can be matched and in what way. This is called a multi. See |/multi| for an overview.	*/star* */\star* *E56* *	(use \* when 'magic' is not set)	Matches 0 or more of the preceding atom, as many as possible. Example 'nomagic'	matches 	a* a\*	"", "a", "aa", "aaa", etc.	.* \.\*	anything, also an empty string, no end-of-line	\_.* \_.\*	everything up to the end of the buffer	\_.*END \_.\*END	everything up to and including the last "END"	in the buffer	Exception: When "*" is used at the start of the pattern or just after	"^" it matches the star character.	Be aware that repeating "\_." can match a lot of text and take a long	time. For example, "\_.*END" matches all text from the current	position to the last occurrence of "END" in the file. Since the "*"	will match as many as possible, this first skips over all lines until	the end of the file and then tries matching "END", backing up one	character at a time.	*/\+* *E57* \+	Matches 1 or more of the preceding atom, as many as possible. {not in	Vi} Example	matches 	^.\+$	any non-empty line	\s\+	white space of at least one character	*/\=* \=	Matches 0 or 1 of the preceding atom, as many as possible. {not in Vi} Example	matches 	foo\=	"fo" and "foo"	*/\?* \?	Just like \=. Cannot be used when searching backwards with the "?"	command. {not in Vi}	*/\{* *E58* *E60* *E554* \{n,m}	Matches n to m of the preceding atom, as many as possible \{n}	Matches n of the preceding atom \{n,}	Matches at least n of the preceding atom, as many as possible \{,m}	Matches 0 to m of the preceding atom, as many as possible \{}	Matches 0 or more of the preceding atom, as many as possible (like *)	*/\{-* \{-n,m}	matches n to m of the preceding atom, as few as possible \{-n}	matches n of the preceding atom \{-n,}	matches at least n of the preceding atom, as few as possible \{-,m}	matches 0 to m of the preceding atom, as few as possible \{-}	matches 0 or more of the preceding atom, as few as possible	{Vi does not have any of these} n and m are positive decimal numbers or zero	*non-greedy*	If a "-" appears immediately after the "{", then a shortest match	first algorithm is used (see example below). In particular, "\{-}" is	the same as "*" but uses the shortest match first algorithm. BUT: A	match that starts earlier is preferred over a shorter match: "a\{-}b"	matches "aaab" in "xaaab". Example	matches 	ab\{2,3}c	"abbc" or "abbbc"	a\{5}	"aaaaa"	ab\{2,}c	"abbc", "abbbc", "abbbbc", etc.	ab\{,3}c	"ac", "abc", "abbc" or "abbbc"	a[bc]\{3}d	"abbbd", "abbcd", "acbcd", "acccd", etc.	a\(bc\)\{1,2}d	"abcd" or "abcbcd"	a[bc]\{-}[cd]	"abc" in "abcd"	a[bc]*[cd]	"abcd" in "abcd"	The } may optionally be preceded with a backslash: \{n,m\}.	*/\@=* \@=	Matches the preceding atom with zero width. {not in Vi}	Like "(?=pattern)" in Perl. Example	matches 	foo\(bar\)\@=	"foo" in "foobar"	foo\(bar\)\@=foo	nothing	*/zero-width*	When using "\@=" (or "^", "$", "\<", "\>") no characters are included	in the match. These items are only used to check if a match can be	made. This can be tricky, because a match with following items will	be done in the same position. The last example above will not match	"foobarfoo", because it tries match "foo" in the same position where	"bar" matched.	Note that using "\&" works the same as using "\@=": "foo\&.." is the	same as "\(foo\)\@=..". But using "\&" is easier, you don't need the	braces.	*/\@!* \@!	Matches with zero width if the preceding atom does NOT match at the	current position. |/zero-width| {not in Vi}	Like '(?!pattern)" in Perl. Example	matches 	foo\(bar\)\@!	any "foo" not followed by "bar"	a.\{-}p\@!	"a", "ap", "app", etc. not followed by a "p"	if \(\(then\)\@!.\)*$	"if " not followed by "then"	Using "\@!" is tricky, because there are many places where a pattern	does not match. "a.*p\@!" will match from an "a" to the end of the	line, because ".*" can match all characters in the line and the "p"	doesn't match at the end of the line. "a.\{-}p\@!" will match any	"a", "ap", "aap", etc. that isn't followed by a "p", because the "."	can match a "p" and "p\@!" doesn't match after that.	You can't use "\@!" to look for a non-match before the matching	position: "\(foo\)\@!bar" will match "bar" in "foobar", because at the	position where "bar" matches, "foo" does not match. To avoid matching	"foobar" you could use "\(foo\)\@!...bar", but that doesn't match a bar at the start of a line. Use "\(foo\)\@<!bar".	*/\@<=* \@<=	Matches with zero width if the preceding atom matches just before what	follows. |/zero-width| {not in Vi}	Like '(?<=pattern)" in Perl, but Vim allows non-fixed-width patterns. Example	matches 	\(an\_s\+\)\@<=file	"file" after "an" and white space or an	end-of-line	For speed it's often much better to avoid this multi. Try using "\zs"	instead |/\zs|. To match the same as the above example:	an\_s\+\zsfile	"\@<=" and "\@<!" check for matches just before what follows.	Theoretically these matches could start anywhere before this position.	But to limit the time needed, only the line where what follows matches	is searched, and one line before that (if there is one). This should	be sufficient to match most things and not be too slow.	The part of the pattern after "\@<=" and "\@<!" are checked for a	match first, thus things like "\1" don't work to reference \(\) inside	the preceding atom. It does work the other way around: Example	matches 	\1\@<=,\([a-z]\+\)	",abc" in "abc,abc"	*/\@<!* \@<!	Matches with zero width if the preceding atom does NOT match just	before what follows. Thus this matches if there is no position in the	current or previous line where the atom matches such that it ends just	before what follows. |/zero-width| {not in Vi}	Like '(?<!pattern)" in Perl, but Vim allows non-fixed-width patterns.	The match with the preceding atom is made to end just before the match	with what follows, thus an atom that ends in ".*" will work.	Warning: This can be slow (because many positions need to be checked	for a match). Example	matches 	\(foo\)\@<!bar	any "bar" that's not in "foobar"	\(\/\/.*\)\@<!in	"in" which is not after "//"	*/\@>* \@>	Matches the preceding atom like matching a whole pattern. {not in Vi}	Like "(?>pattern)" in Perl. Example	matches 	\(a*\)\@>a	nothing (the "a*" takes all the "a"'s, there can't be	another one following)	This matches the preceding atom as if it was a pattern by itself. If	it doesn't match, there is no retry with shorter sub-matches or	anything. Observe this difference: "a*b" and "a*ab" both match	"aaab", but in the second case the "a*" matches only the first two	"a"s. "\(a*\)\@>ab" will not match "aaab", because the "a*" matches	the "aaa" (as many "a"s as possible), thus the "ab" can't match. ============================================================================== 6. Ordinary atoms	*pattern-atoms* An ordinary atom can be:	*/^* ^	At beginning of pattern or after "\|", "\(", "\%(" or "\n": matches	start-of-line; at other positions, matches literal '^'. |/zero-width| Example	matches 	^beep(	the start of the C function "beep" (probably).	*/\^* \^	Matches literal '^'. Can be used at any position in the pattern.	*/\_^* \_^	Matches start-of-line. |/zero-width| Can be used at any position in	the pattern. Example	matches 	\_s*\_^foo	white space and blank lines and then "foo" at	start-of-line	*/$* $	At end of pattern or in front of "\|", "\)" or "\n" ('magic' on):	matches end-of-line <EOL>; at other positions, matches literal '$'.	|/zero-width|	*/\$* \$	Matches literal '$'. Can be used at any position in the pattern.	*/\_$* \_$	Matches end-of-line. |/zero-width| Can be used at any position in the pattern. Note that "a\_$b" never matches, since "b" cannot match an	end-of-line. Use "a\nb" instead |/\n|. Example	matches 	foo\_$\_s*	"foo" at end-of-line and following white space and	blank lines .	(with 'nomagic': \.)	*/.* */\.*	Matches any single character, but not an end-of-line.	*/\_.* \_.	Matches any single character or end-of-line.	Careful: "\_.*" matches all text to the end of the buffer!	*/\<* \<	Matches the beginning of a word: The next char is the first char of a word. The 'iskeyword' option specifies what is a word character.	|/zero-width|	*/\>* \>	Matches the end of a word: The previous char is the last char of a word. The 'iskeyword' option specifies what is a word character.	|/zero-width|	*/\zs* \zs	Matches at any position, and sets the start of the match there: The	next char is the first char of the whole match. |/zero-width|	Example: /^\s*\zsif	matches an "if" at the start of a line, ignoring white space.	Can be used multiple times, the last one encountered in a matching	branch is used. Example: /\(.\{-}\zsFab\)\{3}	Finds the third occurrence of "Fab".	{not in Vi} {not available when compiled without the |+syntax| feature}	*/\ze* \ze	Matches at any position, and sets the end of the match there: The	previous char is the last char of the whole match. |/zero-width|	Can be used multiple times, the last one encountered in a matching	branch is used.	Example: "end\ze\(if\|for\)" matches the "end" in "endif" and	"endfor".	{not in Vi} {not available when compiled without the |+syntax| feature}	*/\%^* *start-of-file* \%^	Matches start of the file. When matching with a string, matches the	start of the string. {not in Vi}	For example, to find the first "VIM" in a file: /\%^\_.\{-}\zsVIM	*/\%$* *end-of-file* \%$	Matches end of the file. When matching with a string, matches the	end of the string. {not in Vi}	Note that this does NOT find the last "VIM" in a file: /VIM\_.\{-}\%$	It will find the next VIM, because the part after it will always	match. This one will find the last "VIM" in the file: /VIM\ze\(\(VIM\)\@!\_.\)*\%$	This uses |/\@!| to ascertain that "VIM" does NOT match in any	position after the first "VIM".	Searching from the end of the file backwards is easier!	*/\%V* \%V	Match inside the Visual area. When Visual mode has already been	stopped match in the area that |gv| would reselect.	This is a |/zero-width| match. To make sure the whole pattern is	inside the Visual area put it at the start and end of the pattern,	e.g.: /\%Vfoo.*bar\%V	Only works for the current buffer.	*/\%#* *cursor-position* \%#	Matches with the cursor position. Only works when matching in a	buffer displayed in a window. {not in Vi}	WARNING: When the cursor is moved after the pattern was used, the	result becomes invalid. Vim doesn't automatically update the matches.	This is especially relevant for syntax highlighting and 'hlsearch'.	In other words: When the cursor moves the display isn't updated for	this change. An update is done for lines which are changed (the whole	line is updated) or when using the |CTRL-L| command (the whole screen	is updated). Example, to highlight the word under the cursor: /\k*\%#\k*	When 'hlsearch' is set and you move the cursor around and make changes	this will clearly show when the match is updated or not.	*/\%'m* */\%<'m* */\%>'m* \%'m	Matches with the position of mark m. \%<'m	Matches before the position of mark m. \%>'m	Matches after the position of mark m.	Example, to highlight the text from mark 's to 'e: /.\%>'s.*\%<'e..	Note that two dots are required to include mark 'e in the match. That	is because "\%<'e" matches at the character before the 'e mark, and	since it's a |/zero-width| match it doesn't include that character.	{not in Vi}	WARNING: When the mark is moved after the pattern was used, the result	becomes invalid. Vim doesn't automatically update the matches.	Similar to moving the cursor for "\%#" |/\%#|.	*/\%l* */\%>l* */\%<l* \%23l	Matches in a specific line. \%<23l	Matches above a specific line (lower line number). \%>23l	Matches below a specific line (higher line number).	These three can be used to match specific lines in a buffer. The "23"	can be any line number. The first line is 1. {not in Vi}	WARNING: When inserting or deleting lines Vim does not automatically	update the matches. This means Syntax highlighting quickly becomes	wrong.	Example, to highlight the line where the cursor currently is: :exe '/\%' . line(".") . 'l.*'	When 'hlsearch' is set and you move the cursor around and make changes	this will clearly show when the match is updated or not.	*/\%c* */\%>c* */\%<c* \%23c	Matches in a specific column. \%<23c	Matches before a specific column. \%>23c	Matches after a specific column.	These three can be used to match specific columns in a buffer or	string. The "23" can be any column number. The first column is 1.	Actually, the column is the byte number (thus it's not exactly right	for multi-byte characters). {not in Vi}	WARNING: When inserting or deleting text Vim does not automatically	update the matches. This means Syntax highlighting quickly becomes	wrong.	Example, to highlight the column where the cursor currently is: :exe '/\%' . col(".") . 'c'	When 'hlsearch' is set and you move the cursor around and make changes	this will clearly show when the match is updated or not.	Example for matching a single byte in column 44: /\%>43c.\%<46c	Note that "\%<46c" matches in column 45 when the "." matches a byte in	column 44.	*/\%v* */\%>v* */\%<v* \%23v	Matches in a specific virtual column. \%<23v	Matches before a specific virtual column. \%>23v	Matches after a specific virtual column.	These three can be used to match specific virtual columns in a buffer	or string. When not matching with a buffer in a window, the option	values of the current window are used (e.g., 'tabstop').	The "23" can be any column number. The first column is 1.	Note that some virtual column positions will never match, because they	are halfway through a tab or other character that occupies more than	one screen character. {not in Vi}	WARNING: When inserting or deleting text Vim does not automatically	update highlighted matches. This means Syntax highlighting quickly	becomes wrong.	Example, to highlight all the characters after virtual column 72: /\%>72v.*	When 'hlsearch' is set and you move the cursor around and make changes	this will clearly show when the match is updated or not.	To match the text up to column 17: /.*\%17v	Column 17 is included, because that's where the "\%17v" matches,	even though this is a |/zero-width| match. Adding a dot to match the	next character has the same result: /.*\%17v.	This command does the same thing, but also matches when there is no	character in column 17: /.*\%<18v. Character classes: {not in Vi} \i	identifier character (see 'isident' option)	*/\i* \I	like "\i", but excluding digits	*/\I* \k	keyword character (see 'iskeyword' option)	*/\k* \K	like "\k", but excluding digits	*/\K* \f	file name character (see 'isfname' option)	*/\f* \F	like "\f", but excluding digits	*/\F* \p	printable character (see 'isprint' option)	*/\p* \P	like "\p", but excluding digits	*/\P* NOTE: the above also work for multi-byte characters. The ones below only match ASCII characters, as indicated by the range.	*whitespace* *white-space* \swhitespace character: <Space> and <Tab>*/\s* \S	non-whitespace character; opposite of \s	*/\S* \d	digit:	[0-9]	*/\d* \D	non-digit:	[^0-9]	*/\D* \x	hex digit:	[0-9A-Fa-f]	*/\x* \X	non-hex digit:	[^0-9A-Fa-f]	*/\X* \ooctal digit:	[0-7]	*/\o* \O	non-octal digit:	[^0-7]	*/\O* \wword character:	[0-9A-Za-z_]	*/\w* \W	non-word character:	[^0-9A-Za-z_]	*/\W* \h	head of word character:	[A-Za-z_]	*/\h* \H	non-head of word character:	[^A-Za-z_]	*/\H* \a	alphabetic character:	[A-Za-z]	*/\a* \A	non-alphabetic character:	[^A-Za-z]	*/\A* \llowercase character:	[a-z]	*/\l* \L	non-lowercase character:	[^a-z]	*/\L* \uuppercase character:	[A-Z]	*/\u* \U	non-uppercase character	[^A-Z]	*/\U*	NOTE: Using the atom is faster than the [] form.	NOTE: 'ignorecase', "\c" and "\C" are not used by character classes.	*/\_* *E63* */\_i* */\_I* */\_k* */\_K* */\_f* */\_F*	*/\_p* */\_P* */\_s* */\_S* */\_d* */\_D* */\_x* */\_X*	*/\_o* */\_O* */\_w* */\_W* */\_h* */\_H* */\_a* */\_A*	*/\_l* */\_L* */\_u* */\_U* \_x	Where "x" is any of the characters above: The character class with	end-of-line added (end of character classes) \e	matches <Esc>*/\e* \t	matches <Tab>*/\t* \r	matches <CR>*/\r* \b	matches <BS>*/\b* \n	matches an end-of-line	*/\n*	When matching in a string instead of buffer text a literal newline	character is matched. ~	matches the last given substitute string	*/~* */\~* \(\)	A pattern enclosed by escaped parentheses.	*/\(* */\(\)* */\)*	E.g., "\(^a\)" matches 'a' at the start of a line. *E51* *E54* *E55* \1 Matches the same string that was matched by	*/\1* *E65*	the first sub-expression in \( and \). {not in Vi}	Example: "\([a-z]\).\1" matches "ata", "ehe", "tot", etc. \2 Like "\1", but uses second sub-expression,	*/\2* ...*/\3* \9 Like "\1", but uses ninth sub-expression.	*/\9*	Note: The numbering of groups is done based on which "\(" comes first	in the pattern (going left to right), NOT based on what is matched	first. \%(\)	A pattern enclosed by escaped parentheses.	*/\%(\)* */\%(* *E53*	Just like \(\), but without counting it as a sub-expression. This	allows using more groups and it's a little bit faster.	{not in Vi} xA single character, with no special meaning, matches itself	*/\* */\\* \x	A backslash followed by a single character, with no special meaning,	is reserved for future expansions [](with 'nomagic': \[])	*/[]* */\[]* */\_[]* */collection* \_[]	A collection. This is a sequence of characters enclosed in brackets.	It matches any single character in the collection. Example	matches 	[xyz]	any 'x', 'y' or 'z'	[a-zA-Z]$	any alphabetic character at the end of a line	\c[a-z]$	same	*/[\n]*	With "\_" prepended the collection also includes the end-of-line.	The same can be done by including "\n" in the collection. The	end-of-line is also matched when the collection starts with "^"! Thus	"\_[^ab]" matches the end-of-line and any character but "a" and "b".	This makes it Vi compatible: Without the "\_" or "\n" the collection	does not match an end-of-line.	*E769*	When the ']' is not there Vim will not give an error message but	assume no collection is used. Useful to search for '['. However, you do get E769 for internal searching.	If the sequence begins with "^", it matches any single character NOT	in the collection: "[^xyz]" matches anything but 'x', 'y' and 'z'.	- If two characters in the sequence are separated by '-', this is shorthand for the full list of ASCII characters between them. E.g., "[0-9]" matches any decimal digit. Non-ASCII characters can be used, but the character values must not be more than 256 apart.	- A character class expression is evaluated to the set of characters belonging to that character class. The following character classes are supported:  Name	Contents  *[:alnum:]* [:alnum:] letters and digits *[:alpha:]* [:alpha:] letters *[:blank:]* [:blank:] space and tab characters *[:cntrl:]* [:cntrl:] control characters *[:digit:]* [:digit:] decimal digits *[:graph:]* [:graph:] printable characters excluding space *[:lower:]* [:lower:] lowercase letters (all letters when 'ignorecase' is used) *[:print:]* [:print:] printable characters including space *[:punct:]* [:punct:] punctuation characters *[:space:]* [:space:] whitespace characters *[:upper:]* [:upper:] uppercase letters (all letters when 'ignorecase' is used) *[:xdigit:]* [:xdigit:] hexadecimal digits *[:return:]* [:return:]the <CR> character *[:tab:]* [:tab:]the <Tab> character *[:escape:]* [:escape:]the <Esc> character *[:backspace:]* [:backspace:]the <BS> character The brackets in character class expressions are additional to the brackets delimiting a collection. For example, the following is a plausible pattern for a UNIX filename: "[-./[:alnum:]_~]\+" That is, a list of at least one character, each of which is either '-', '.', '/', alphabetic, numeric, '_' or '~'. These items only work for 8-bit characters.	*/[[=* *[==]*	- An equivalence class. This means that characters are matched that have almost the same meaning, e.g., when ignoring accents. The form is:	[=a=] Currently this is only implemented for latin1. Also works for the latin1 characters in utf-8 and latin9.	*/[[.* *[..]*	- A collation element. This currently simply accepts a single character in the form:	[.a.] */\]*	- To include a literal ']', '^', '-' or '\' in the collection, put a backslash before it: "[xyz\]]", "[\^xyz]", "[xy\-z]" and "[xyz\\]". (Note: POSIX does not support the use of a backslash this way). For ']' you can also make it the first character (following a possible "^"): "[]xyz]" or "[^]xyz]" {not in Vi}. For '-' you can also make it the first or last character: "[-xyz]", "[^-xyz]" or "[xyz-]". For '\' you can also let it be followed by any character that's not in "^]-\bdertnoUux". "[\xyz]" matches '\', 'x', 'y' and 'z'. It's better to use "\\" though, future expansions may use other characters after '\'.	- The following translations are accepted when the 'l' flag is not included in 'cpoptions' {not in Vi}:	\e<Esc>	\t<Tab>	\r<CR>(NOT end-of-line!)	\b<BS>	\n	line break, see above |/[\n]|	\d123	decimal number of character	\o40octal number of character up to 0377	\x20	hexadecimal number of character up to 0xff	\u20AC	hex. number of multibyte character up to 0xffff	\U1234	hex. number of multibyte character up to 0xffffffff NOTE: The other backslash codes mentioned above do not work inside []!	- Matching with a collection can be slow, because each character in the text has to be compared with each character in the collection. Use one of the other atoms above when possible. Example: "\d" is much faster than "[0-9]" and matches the same characters.	*/\%[]* *E69* *E70* *E369* \%[]	A sequence of optionally matched atoms. This always matches.	It matches as much of the list of atoms it contains as possible. Thus	it stops at the first atom that doesn't match. For example: /r\%[ead]	matches "r", "re", "rea" or "read". The longest that matches is used.	To match the Ex command "function", where "fu" is required and	"nction" is optional, this would work: /\<fu\%[nction]\>	The end-of-word atom "\>" is used to avoid matching "fu" in "full".	It gets more complicated when the atoms are not ordinary characters.	You don't often have to use it, but it is possible. Example: /\<r\%[[eo]ad]\>	Matches the words "r", "re", "ro", "rea", "roa", "read" and "road".	There can be no \(\), \%(\) or \z(\) items inside the [] and \%[] does	not nest.	To include a "[" use "[[]" and for "]" use []]", e.g.,: /index\%[[[]0[]]]	matches "index" "index[", "index[0" and "index[0]".	{not available when compiled without the |+syntax| feature}	*/\%d* */\%x* */\%o* */\%u* */\%U* *E678* \%d123	Matches the character specified with a decimal number. Must be	followed by a non-digit. \%o40	Matches the character specified with an octal number up to 0377.	Numbers below 040 must be followed by a non-octal digit or a non-digit. \%x2a	Matches the character specified with up to two hexadecimal characters. \%u20AC	Matches the character specified with up to four hexadecimal	characters. \%U1234abcd	Matches the character specified with up to eight hexadecimal	characters. ============================================================================== 7. Ignoring case in a pattern*/ignorecase* If the 'ignorecase' option is on, the case of normal letters is ignored. 'smartcase' can be set to ignore case when the pattern contains lowercase letters only.	*/\c* */\C* When "\c" appears anywhere in the pattern, the whole pattern is handled like 'ignorecase' is on. The actual value of 'ignorecase' and 'smartcase' is ignored. "\C" does the opposite: Force matching case for the whole pattern. {only Vim supports \c and \C} Note that 'ignorecase', "\c" and "\C" are not used for the character classes. Examples:  pattern	'ignorecase' 'smartcase'	matches 	foo off	-	foo	foo on	-	foo Foo FOO	Foo on	off	foo Foo FOO	Foo on	on Foo	\cfoo -	-	foo Foo FOO	foo\C -	-	foo Technical detail:	*NL-used-for-Nul* <Nul> characters in the file are stored as <NL> in memory. In the display they are shown as "^@". The translation is done when reading and writing files. To match a <Nul> with a search pattern you can just enter CTRL-@ or "CTRL-V 000". This is probably just what you expect. Internally the character is replaced with a <NL> in the search pattern. What is unusual is that typing CTRL-V CTRL-J also inserts a <NL>, thus also searches for a <Nul> in the file. {Vi cannot handle <Nul> characters in the file at all}	*CR-used-for-NL* When 'fileformat' is "mac", <NL> characters in the file are stored as <CR> characters internally. In the text they are shown as "^J". Otherwise this works similar to the usage of <NL> for a <Nul>. When working with expression evaluation, a <NL> character in the pattern matches a <NL> in the string. The use of "\n" (backslash n) to match a <NL> doesn't work there, it only works to match text in the buffer.	*pattern-multi-byte* Patterns will also work with multi-byte characters, mostly as you would expect. But invalid bytes may cause trouble, a pattern with an invalid byte will probably never match. ============================================================================== 8. Composing characters	*patterns-composing*	*/\Z* When "\Z" appears anywhere in the pattern, composing characters are ignored. Thus only the base characters need to match, the composing characters may be different and the number of composing characters may differ. Only relevant when 'encoding' is "utf-8". When a composing character appears at the start of the pattern of after an item that doesn't include the composing character, a match is found at any character that includes this composing character. When using a dot and a composing character, this works the same as the composing character by itself, except that it doesn't matter what comes before this. The order of composing characters matters, even though changing the order doesn't change what a character looks like. This may change in the future. ============================================================================== 9. Compare with Perl patterns	*perl-patterns* Vim's regexes are most similar to Perl's, in terms of what you can do. The difference between them is mostly just notation; here's a summary of where they differ: Capability	in Vimspeak	in Perlspeak  force case insensitivity	\c	(?i) force case sensitivity	\C	(?-i) backref-less grouping	\%(atom\)	(?:atom) conservative quantifiers	\{-n,m}	*?, +?, ??, {}? 0-width match	atom\@=	(?=atom) 0-width non-match	atom\@!	(?!atom) 0-width preceding match	atom\@<=	(?<=atom) 0-width preceding non-match	atom\@<!	(?<!atom) match without retry	atom\@>	(?>atom) Vim and Perl handle newline characters inside a string a bit differently: In Perl, ^ and $ only match at the very beginning and end of the text, by default, but you can set the 'm' flag, which lets them match at embedded newlines as well. You can also set the 's' flag, which causes a . to match newlines as well. (Both these flags can be changed inside a pattern using the same syntax used for the i flag above, BTW.) On the other hand, Vim's ^ and $ always match at embedded newlines, and you get two separate atoms, \%^ and \%$, which only match at the very start and end of the text, respectively. Vim solves the second problem by giving you the \_ "modifier": put it in front of a . or a character class, and they will match newlines as well. Finally, these constructs are unique to Perl: - execution of arbitrary code in the regex: (?{perl code}) - conditional expressions: (?(condition)true-expr|false-expr) ...and these are unique to Vim: - changing the magic-ness of a pattern: \v \V \m \M (very useful for avoiding backslashitis) - sequence of optionally matching atoms: \%[atoms] - \& (which is to \| what "and" is to "or"; it forces several branches to match at one spot) - matching lines/columns by number: \%5l \%5c \%5v - setting the start and end of the match: \zs \ze ============================================================================== 10. Highlighting matches	*match-highlight*	*:mat* *:match* :mat[ch] {group} /{pattern}/	Define a pattern to highlight in the current window. It will	be highlighted with {group}. Example: :highlight MyGroup ctermbg=green guibg=green :match MyGroup /TODO/	Instead of // any character can be used to mark the start and	end of the {pattern}. Watch out for using special characters,	such as '"'' and '|'.	{group} must exist at the moment this command is executed.	The {group} highlighting still applies when a character is	to be highlighted for 'hlsearch', as the highlighting for	matches is given higher priority than that of 'hlsearch'. Syntax highlighting (see 'syntax') is also overruled by	matches.	Note that highlighting the last used search pattern with 'hlsearch' is used in all windows, while the pattern defined	with ":match" only exists in the current window. It is kept	when switching to another buffer. 'ignorecase' does not apply, use |/\c| in the pattern to	ignore case. Otherwise case is not ignored. 'redrawtime' defines the maximum time searched for pattern	matches.	When matching end-of-line and Vim redraws only part of the	display you may get unexpected results. That is because Vim	looks for a match in the line where redrawing starts.	Also see |matcharg()| and |getmatches()|. The former returns	the highlight group and pattern of a previous |:match|	command. The latter returns a list with highlight groups and	patterns defined by both |matchadd()| and |:match|.	Highlighting matches using |:match| are limited to three	matches (aside from |:match|, |:2match| and |:3match|are	available). |matchadd()| does not have this limitation and in	addition makes it possible to prioritize matches.	Another example, which highlights all characters in virtual	column 72 and more: :highlight rightMargin term=bold ctermfg=blue guifg=blue :match rightMargin /.\%>72v/	To highlight all character that are in virtual column 7: :highlight col8 ctermbg=grey guibg=grey :match col8 /\%<8v.\%>7v/	Note the use of two items to also match a character that	occupies more than one virtual column, such as a TAB. :mat[ch] :mat[ch] none	Clear a previously defined match pattern. :2mat[ch] {group} /{pattern}/	*:2match* :2mat[ch] :2mat[ch] none :3mat[ch] {group} /{pattern}/	*:3match* :3mat[ch] :3mat[ch] none	Just like |:match| above, but set a separate match. Thus	there can be three matches active at the same time. The match	with the lowest number has priority if several match at the	same position.	The ":3match" command is used by the |matchparen| plugin. You	are suggested to use ":match" for manual matching and	":2match" for another plugin. top - main help file