Ejemplos de expresiones regulares

Regex Syntax

Characters

	Description	Example
		match	Doesn't match
.	Any character	X	[everything matches]
[abcde]	A character of the set {abcde}*	a	A or f or #
[^abcde]	A character which is not in the set {abcde}*	A or g	c
[a-z0-9]	A character in the sets {a,b,c...z} {0,1,2...9}*	b	B or #
\w	[a-zA-Z0-9_] (literal or digit or underscore)	B or 9 or _	# or " "(space)
\W	[^a-zA-Z0-9_] (not literal nor digit nor underscore)	# or " " (space)	B or 9 _
\d	[0-9] (digit)	8	A or #
\D	[^0-9] (not a digit)	A or #	8
\s	Space	" "	A or 8 or #
\S	No space	A or 8 or #	" "
\xdd	dd is a hexadecimal number. Matches the character with ascii code dd.	\x41 matches A \x40 matches @
\udddd	dddd is a hexadecimal character. Matches the character with unicode code dddd.	\u0013 matches # \u0030 matches @

* Metacharacters Inside Character Classes:

Validar direccion email:

\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*

Validar direccion email (permite email vacio):

^(\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*)??\s*$

URL (protocolo, dominio, puerto, archivo, parametros):

\b(?i:https?|ftp)(://([\w.]+(:\d{1,4})?)(/[\w+&@#/%=~_!:,.;]*))?(\?[\w+&@#/%=~_|!:,.;]*)?

Valida IP: from 0.0.0.0 a 255.255.255.255 (no capture)

\b(?:(?:25[0-5]|2[0-4]\d|[01]?\d{1,2})\.){3}(?:25[0-5]|2[0-4]\d|[01]?\d{1,2})\b

Path (drive, folder, filename):

\b(?i:[a-z]):\\([^/:*?"<>]*\\)?([^\\/:*?"<>]*)

Valida caracteres sean numeros, letras y subrayado:

^[\w]*$

Fuente