User:Kylu/regex

Stupid Regex Tricks

IP & MAC addresses

• IP address: /^((25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9][0-9]|[0-9])\.){3}(25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9][0-9]|[0-9])$/
• MAC address: /^[0-9a-fA-F]{2}:[0-9a-fA-F]{2}:[0-9a-fA-F]{2}:[0-9a-fA-F]{2}:[0-9a-fA-F]{2}:[0-9a-fA-F]{2}$/
• IP address: ^([[:xdigit:]]{2}:){5}[[:xdigit:]]{2}$
• IP address (IPv4): /^((25[0-5]|(2[0-4]|1[0-9]|[1-9]|)[0-9])(\.|$)){4}/
• IP address (IPv6): /^(([0-9a-fA-F]{2})(:|$)){6}$/

RFC 822 address validation

• Best: http://ex-parrot.com/~pdw/Mail-RFC822-Address.html (Long regex)
• Okay: ([^\\x00-\\x20\\x22\\x28\\x29\\x2c\\x2e\\x3a-\\x3c\\x3e\\x40\\x5b-\\x5d\\x7f-\\xff]+|\\x22([^\\x0d\\x22\\x5c\\x80-\\xff]|\\x5c[\\x00-\\x7f])*\\x22)(\\x2e([^\\x00-\\x20\\x22\\x28\\x29\\x2c\\x2e\\x3a-\\x3c\\x3e\\x40\\x5b-\\x5d\\x7f-\\xff]+|\\x22([^\\x0d\\x22\\x5c\\x80-\\xff]|\\x5c\\x00-\\x7f)*\\x22))*\\x40([^\\x00-\\x20\\x22\\x28\\x29\\x2c\\x2e\\x3a-\\x3c\\x3e\\x40\\x5b-\\x5d\\x7f-\\xff]+|\\x5b([^\\x0d\\x5b-\\x5d\\x80-\\xff]|\\x5c[\\x00-\\x7f])*\\x5d)(\\x2e([^\\x00-\\x20\\x22\\x28\\x29\\x2c\\x2e\\x3a-\\x3c\\x3e\\x40\\x5b-\\x5d\\x7f-\\xff]+|\\x5b([^\\x0d\\x5b-\\x5d\\x80-\\xff]|\\x5c[\\x00-\\x7f])*\\x5d))*

Misc

• "This regex matches a number: interger or float, scientific notation or plain, plus or minus": [-+]?(?:\b[0-9]+(?:\.[0-9]*)?|\.[0-9]+\b)(?:[eE][-+]?[0-9]+\b)?
• Remove trailing whitespaces /\s\+$//e
• US SSN ^(?!000)([0-6]\d{2}|7([0-6]\d|7[012]))([ -]?)(?!00)\d\d\3(?!0000)\d{4}$
• US phone with or without parentheses ^\([0-9]{3}\)\s?[0-9]{3}(-|\s)?[0-9]{4}$|^[0-9]{3}-?[0-9]{3}-?[0-9]{4}$
• ISO Date (19th to 21st century only) ^((18|19|20)\d\d)-(0[1-9]|1[012])-(0[1-9]|1[0-9]|2[0-9]|3[01])$

Real-time Regex analyzer

• http://gskinner.com/RegExr/

References and External Links

• (Useful) Stupid Regex Tricks? Slashdot, November 10, 2009