Regex

Regular expressions

Links

• Regex reference
• http://gnosis.cx/publish/programming/regular_expressions.html
• http://www.zytrax.com/tech/web/regex.htm
• http://www.regular-expressions.info
• https://regex101.com/

Syntax

(?:)

Non-capturing group, so creating a back-reference

Tools

• txt2regex

ZZ

pcre

• pcre

FAQ

Match IP address

'\d{1,3}[-x.]\d{1,3}[-x.]\d{1,3}'

Replace one or more spaces

's/\s\s*/FOO/g'