Template:Regex

This template can be called from the regex chapter of several books.

Usual regular expressions
Character	Type	Explanation
.	Dot	any character
[...]	Brackets	character class: all the enumerated characters in the class
[^...]	Brackets and circumflex	complemented class: all the characters except for the enumerated ones
^	Circumflex	string or line start
$	Dollar	string or line end
\|	Pipe	alternative
(...)	Parenthesis	capture group: also used to limit the range of an alternative
*	Asterisk	0, 1 or several occurrences
+	Plus	1 or several occurrences
?	Interrogation	0 or 1 occurrence

POSIX characters classes^[1]
Classe	Signification
[[:alpha:]]	any letter
[[:digit:]]	any digit
[[:xdigit:]]	hexadecimal characters
[[:alnum:]]	any letter or digit
[[:space:]]	any white space
[[:punct:]]	any punctuation letter
[[:lower:]]	any small cap letter
[[:upper:]]	any capital letter
[[:blank:]]	space or tabulation
[[:graph:]]	displayable et printable characters
[[:cntrl:]]	escaping characters
[[:print:]]	printable characters, except for the control ones

Unicode regex^[2]
Expression	Signification
\A	String start
\b	Start or end of word character
\d	Digit
\D	Non digit
\s	Space characters
\S	Non space characters
\w	Letter, digit or underscore
\W	Non letter, digit or underscore character
\X	Unicode character
\z	String end

Debugger: https://regex101.com/