A cheat sheet about regular expressions used in Sublime Text.
Special characters#
| expression | Description |
|---|---|
. | Match any character |
^ | Match line begin |
$ | Match line end |
* | Match previous RE 0 or more times greedily |
*? | Match previous RE 0 or more times non-greedily |
+ | Match previous RE 1 or more times greedily |
+? | Match previous RE 1 or more times non-greedily |
? | Match previous RE 0 or 1 time greedily |
?? | Match previous RE 0 or 1 time non-greedily |
A|B | Match either RE A or B |
{m} | Match previous RE exactly m times |
{m,n} | Match previous RE m to n times greedily |
{m, n}? | Match previous RE m to n times, non-greedily |
Character set#
| expression | Description |
|---|---|
[abc] | Match either a, b or c |
[^abc] | Match any character not in this set (i.e., not a, b and c) |
[a-z] | Match the range from a to z |
[a-f2-8] | Match the range from a to f or the range from 2 to 8 |
[a\-z] | Match a, - or z |
[a-] | Match a, - |
[-a] | Match -, a |
[{}*|()[]+\^$.?] | Match either one of the chacters in []{}*|()+^$?. |
- Note that you can also use character class inside
[], for example,[\w]matches any character inwordcharacter class.
Character class#
“Multiple character” character class#
An expression of the form [[:name:]] matches the named character class name.
| class name | Description |
|---|---|
alnum | Any alpha-numeric character |
alpha | Any alphabetic character. |
digit | Any decimal digit. |
xdigit | Any hexadecimal digit character. |
lower | Any lower case character. |
upper | Any upper case character. |
cntrl | Any control character1. |
print | Any printable character. |
punct | Any punctuation character. 2 |
space | Any whitespace character. 3 |
word | Any word character (alphanumeric characters plus the underscore). |
Note: To use upper and lower, you have to enable case sensitve search.
“Single character” character class#
| class name | Description |
|---|---|
\d | Equal to [[:digit:]] |
\l | Equal to [[:lower:]] |
\u | Equal to [[:upper:]] |
\s | Equal to [[:space:]] |
\w | Equal to [[:word:]] |
\D | Equal to [^[:digit:]] |
\L | Equal to [^[:lower:]] |
\U | Equal to [^[:upper:]] |
\W | Equal to [^[:word:]] |
Regex groups#
Defining capture groups#
| expression | Description |
|---|---|
(?<NAME>pattern) | Define a regex group named NAME which you can later refer to with \g{NAME} |
(?=pattern) | Positive lookahead, consumes zero characters, the preceding RE only matches if this matches |
(?!pattern) | Negative lookahead, consumes zero characters, the preceding RE only matches if this does not match |
(?<=pattern) | Positive lookbehind, consumes zero characters, the following RE will only match if preceded with this fixed length RE. |
(?<!pattern) | Negative lookbehind, consumes zero characters, the following RE will only match if not preceded with this fixed length RE. |
Refering to matching groups (capture groups)#
| expression | Description |
|---|---|
\1 | Refer to first regex group |
\g{1} | Refer to first regex group |
\g{12} | Refer to 12th regex group |
\g{-1} | Refer to last regex group |
\g{-2} | Refer to last but one regex group |
- The regex groups are indexed by the order of their opening braces.
- Note the
\g{NUM}form allows for matching regex group index larger than 9, for example,\g{12}.
Miscellaneous#
Escapes#
| class name | Description |
|---|---|
\xdd | A hexadecimal escape sequence - matches the single character whose code point is 0xdd. |
\x{dddd} | A hexadecimal escape sequence - matches the single character whose code point is 0xdddd. |
Word boundaries#
The following escape sequences match the boundaries of words:
| class name | Description |
|---|---|
\< | Matches the start of a word. |
\> | Matches the end of a word. |
\b | Matches a word boundary (the start or end of a word). |
\B | Matches only when not at a word boundary. |
References#
- https://www.boost.org/doc/libs/1_44_0/libs/regex/doc/html/boost_regex/syntax/perl_syntax.html
- http://docs.sublimetext.info/en/latest/search_and_replace/search_and_replace_overview.html
- https://github.com/stajahlee/sublime-cheat-sheets/blob/master/cheat-sheets/Regular%20Expressions.cheatsheet
- Character class
The title image is taken from here.
Control character explanation: https://en.wikipedia.org/wiki/Control_character ↩︎
There are 14 punctuation marks in English: https://grammar.yourdictionary.com/punctuation/what/fourteen-punctuation-marks.html ↩︎
For whitespace characters, see https://en.wikipedia.org/wiki/Whitespace_character ↩︎