- Regular Expression Patterns
- Non Greedy
:help non-greedy- Instead of
.*use.\{-}
- Comprehensive looking tutorial
- Huge Reference - vimregex.xom
- Non Greedy
Tips
- Use
\zsto mark the start of the match and\zeto mark the end.
Misc
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 more as many as possible
|/\+| \+ \+ 1 or more as many as possible (*)
|/\=| \= \= 0 or 1 as many as possible (*)
|/\?| \? \? 0 or 1 as many as possible (*)
|/\{| \{n,m} \{n,m} n to m as many as possible (*)
\{n} \{n} n exactly (*)
\{n,} \{n,} at least n as many as possible (*)
\{,m} \{,m} 0 to m as many as possible (*)
\{} \{} 0 or more as many as possible (same as *) (*)
|/\{-| \{-n,m} \{-n,m} n to m as few as possible (*)
\{-n} \{-n} n exactly (*)
\{-n,} \{-n,} at least n as few as possible (*)
\{-,m} \{-,m} 0 to m as few as possible (*)
\{-} \{-} 0 or more as 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 \%'m mark 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 \s whitespace 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 \o octal digit: [0-7]
|/\O| \O \O non-octal digit: [^0-7]
|/\w| \w \w word 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 \l lowercase character: [a-z]
|/\L| \L \L non-lowercase character: [^a-z]
|/\u| \u \u uppercase 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|
x x a 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*
\s whitespace 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*
\o octal digit: [0-7] */\o*
\O non-octal digit: [^0-7] */\O*
\w word 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*
\l lowercase character: [a-z] */\l*
\L non-lowercase character: [^a-z] */\L*
\u uppercase 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}
x A 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
\o40 octal 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.
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 more as many as possible
|/\+| \+ \+ 1 or more as many as possible (*)
|/\=| \= \= 0 or 1 as many as possible (*)
|/\?| \? \? 0 or 1 as many as possible (*)
|/\{| \{n,m} \{n,m} n to m as many as possible (*)
\{n} \{n} n exactly (*)
\{n,} \{n,} at least n as many as possible (*)
\{,m} \{,m} 0 to m as many as possible (*)
\{} \{} 0 or more as many as possible (same as *) (*)
|/\{-| \{-n,m} \{-n,m} n to m as few as possible (*)
\{-n} \{-n} n exactly (*)
\{-n,} \{-n,} at least n as few as possible (*)
\{-,m} \{-,m} 0 to m as few as possible (*)
\{-} \{-} 0 or more as 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 \%'m mark 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 \s whitespace 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 \o octal digit: [0-7]
|/\O| \O \O non-octal digit: [^0-7]
|/\w| \w \w word 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 \l lowercase character: [a-z]
|/\L| \L \L non-lowercase character: [^a-z]
|/\u| \u \u uppercase 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|
x x a 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*
\s whitespace 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*
\o octal digit: [0-7] */\o*
\O non-octal digit: [^0-7] */\O*
\w word 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*
\l lowercase character: [a-z] */\l*
\L non-lowercase character: [^a-z] */\L*
\u uppercase 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}
x A 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
\o40 octal 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.