Regular Expressions 101

Save & Share

  • Current Version: 1
  • Update Regex
    ctrl+⇧+s
  • Save new Regex
    ctrl+s
  • Add to Community Library

Flavor

  • PCRE2 (PHP)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java
  • .NET 7.0 (C#)
  • Rust
  • PCRE (Legacy)
  • Regex Flavor Guide

Function

  • Match
  • Substitution
  • List
  • Unit Tests
Sponsors
There are currently no sponsors. Become a sponsor today!
An explanation of your regex will be automatically generated as you type.
Detailed match information will be displayed here automatically.
  • All Tokens
  • Common Tokens
  • General Tokens
  • Anchors
  • Meta Sequences
  • Quantifiers
  • Group Constructs
  • Character Classes
  • Flags/Modifiers
  • Substitution
  • A single character of: a, b or c
    [abc]
  • A character except: a, b or c
    [^abc]
  • A character in the range: a-z
    [a-z]
  • A character not in the range: a-z
    [^a-z]
  • A character in the range: a-z or A-Z
    [a-zA-Z]
  • Any single character
    .
  • Alternate - match either a or b
    a|b
  • Any whitespace character
    \s
  • Any non-whitespace character
    \S
  • Any digit
    \d
  • Any non-digit
    \D
  • Any word character
    \w
  • Any non-word character
    \W
  • Non-capturing group
    (?:...)
  • Capturing group
    (...)
  • Zero or one of a
    a?
  • Zero or more of a
    a*
  • One or more of a
    a+
  • Exactly 3 of a
    a{3}
  • 3 or more of a
    a{3,}
  • Between 3 and 6 of a
    a{3,6}
  • Start of string
    ^
  • End of string
    $
  • A word boundary
    \b
  • Non-word boundary
    \B

Regular Expression
Processing...

Test String

Code Generator

Language

Generated Code

re = /("FILENAME" "([^\/:*?"<>|]+)")/m str = '130 (UID 1245 BODYSTRUCTURE ((("TEXT" "PLAIN" ("CHARSET" "UTF-8") NIL NIL "QUOTED-PRINTABLE" 847 17 NIL NIL NIL)("TEXT" "HTML" ("CHARSET" "UTF-8") NIL NIL "QUOTED-PRINTABLE" 2009 41 NIL NIL NIL) "ALTERNATIVE" ("BOUNDARY" "000000000000929e4505d59042b1") NIL NIL)("IMAGE" "JPEG" ("NAME" "BS_01.jpg") "<f_kyetquhw1>" NIL "BASE64" 280364 NIL ("ATTACHMENT" ("FILENAME" "BS_(01)_a.jpg")) NIL)("IMAGE" "PNG" ("NAME" "payroll_check_top_format.png") "<f_kyetquio3>" NIL "BASE64" 498210 NIL ("ATTACHMENT" ("FILENAME" "payroll check top format.png")) NIL)("IMAGE" "JPEG" ("NAME" "missouri_dl_3e_1300x884.jpg") "<f_kyetquia2>" NIL "BASE64" 1014040 NIL ("ATTACHMENT" ("FILENAME" "missouri_dl_3e_1300x884.jpg")) NIL)("IMAGE" "JPEG" ("NAME" "1040-1-1_N.jpg") "<f_kyetquhj0>" NIL "BASE64" 4272596 NIL ("ATTACHMENT" ("FILENAME" "1040-1-1_N.jpg")) NIL) "MIXED" ("BOUNDARY" "000000000000929e4705d59042b3") NIL NIL))' # Print the match result str.scan(re) do |match| puts match.to_s end

Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Ruby, please visit: http://ruby-doc.org/core-2.2.0/Regexp.html