Regular Expressions 101

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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
No Match

/
/
gm

Test String

Substitution

Processing...

Code Generator

Language

Generated Code

re = /^(0|[1-9]+[0-9]*) (@[^@]+@ |)([A-Za-z0-9_]+)( [^\n\r]*|)$/m str = '0 @N1@ NOTE Lorem ipsum dolor sit amet 0 HEAD 1 SOUR FTM 2 VERS 22.2.6.950 1 DEST FTM 1 DATE 31 MAR 2017 1 CHAR UTF-8 3 _LINK http://www.facebook.com/1247584965 2 SOUR @S122@ 3 PAGE Facebook update - David Hatch - 6/5/2013 3 _LINK http://www.facebook.com/1247584965 1 RESI 2 DATE BET 1935 AND 1993 2 PLAC San Francisco, California, USA 1 RESI 2 DATE 1994 2 PLAC San Francisco, California, USA 2 SOUR @S605@ 3 DATA 4 TEXT Birth date: 20 Sep 1966 Birth place: Residence date: 1994 5 CONC Residence place: San Francisco, CA 1 RESI 106 Oakcrest Rd 2 DATE 26 MAR 2017 2 PLAC San Anselmo, Marin, California, USA 1 FAMS @F500@ 1 FAMC @F656@ 0 @I923@ INDI 1 NAME Vincent /Crilley/ 1 SEX M 1 FAMS @F254@ 0 @I5899@ INDI 1 NAME Marjorie Edna /Footitt/ 2 SOUR @S506@ 2 SOUR @S176@ 2 SOUR @S168@ 2 SOUR @S624@ 3 DATA 4 TEXT Residence date: Residence place: USA 2 SOUR @S115@ 3 PAGE Year: 1940; Census Place: St Paul, Ramsey, Minnesota; Roll: T627_1996; 4 CONC Page: 11A; Enumeration District: 90-73. 3 DATA 4 _TEXT Birth date: abt 1918 Birth place: North Dakota Residence date: 1 5 CONC Apr 1940 Residence place: St Paul, Ramsey, Minnesota, United States 2 SOUR @S607@ 3 PAGE Year: 1920; Census Place: Carrington, Foster, North Dakota; Roll: 4 CONC T625_1334; Page: 13B; Enumeration District: 117; Image: . 3 DATA' subst = '\\n2($2) 3($3) 4($4) 5($5) 6($6) 7($7) \\n\\n8($8) 9($9) 10($10) 11($11) 12($12) 13($13) 14($14) 15($15) 16($16) 18($18) 20($20) 21($21)\\n\\n\\n\\n' result = str.gsub(re, subst) # Print the result of the substitution puts result

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