regexp cheatsheet

Pattern	Description
.	Any character, except newline
\w	Word
\d	Digit
\s	Whitespace
\W	Not word
\D	Not digit
\S	Not whitespace
[abc]	Any of a, b, or c
[a-e]	Characters between a and e
[1-9]	Digit between 1 and 9
[[:print:]]	Any printable character including spaces
[^abc]	Any character except a, b or c

Pattern	Description
\G	Start of match
^	Start of string *
$	End of string *
\A	Start of string
\Z	End of string
\z	Absolute end of string
\b	A word boundary
\B	Non-word boundary
^abc	Start with abc
abc$	End with abc

For multiline patterns (m flag), ^ and $ will act as start and end of line.

Pattern	Description
\. \* \\	Escape special character used by regex
\t	Tab
\n	Newline
\r	Carriage return

Pattern	Description
(abc)	Capture group
(a|b)	Match a or b
(?:abc)	Match abc, but don’t capture
\1	Substituted with text matched of the 1st capturing group

Pattern	Description
a*	Match 0 or more
a+	Match 1 or more
a?	Match 0 or 1
a{5}	Match exactly 5
a{,3}	Match up to 3
a{3,}	Match 3 or more
a{1,3}	Match between 1 and 3

Pattern	Description
a(?=b)	Match a in baby but not in bay
a(?!b)	Match a in Stan but not in Stab
(?<=a)b	Match b in crabs but not in cribs
(?<!a)b	Match b in fib but not in fab