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

/
/
mg

Test String

Code Generator

Language

Generated Code

// include the latest version of the regex crate in your Cargo.toml extern crate regex; use regex::Regex; fn main() { let regex = Regex::new(r#"(?m)^(?=.*(\.((?![^\.]$)[^\.]*)$)|.*@(?:(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$))(?=^.{6,320}$)(?:[a-zA-Z0-9áàâäãåçéèêëíìîïñóòôöõúùûüýÿæœÁÀÂÄÃÅÇÉÈÊËÍÌÎÏÑÓÒÔÖÕÚÙÛÜÝŸÆŒ!#$%&'*+\/=?^_`{|}~-]+(?:\.[a-zA-Z0-9áàâäãåçéèêëíìîïñóòôöõúùûüýÿæœÁÀÂÄÃÅÇÉÈÊËÍÌÎÏÑÓÒÔÖÕÚÙÛÜÝŸÆŒ!#$%&'*+\/=?^_`{|}~-]+)*|"(?:[\xE1\xE0\xE2\xE4\xE3\xE5\xE7\xE9\xE8\xEA\xEB\xED\xEC\xEE\xEF\xF1\xF3\xF2\xF4\xF6\xF5\xFA\xF9\xFB\xFC\xFD\xFF\xE6\xC1\xC0\xC2\xC4\xC3\xC5\xC7\xC9\xC8\xCA\xCB\xCD\xCC\xCE\xCF\xD1\xD3\xD2\xD4\xD6\xD5\xDA\xD9\xDB\xDC\xDD\xC6\x01-\x08\x0b\x0c\x0e-\x1f\x21\x23-\x5b\x5d-\x7f\s]|\\[\x01-\x09\x0b\x0c\x0e-\x7f])*")(?:(?=@(?:[0-9]{1,3}.){3}[0-9]{1,3})@(?:(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))$|(?!@(?:[0-9]{1,3}.){4,}$)@(?:(?:[a-zA-Z0-9áàâäãåçéèêëíìîïñóòôöõúùûüýÿæœÁÀÂÄÃÅÇÉÈÊËÍÌÎÏÑÓÒÔÖÕÚÙÛÜÝŸÆŒ](?:[a-zA-Z0-9áàâäãåçéèêëíìîïñóòôöõúùûüýÿæœÁÀÂÄÃÅÇÉÈÊËÍÌÎÏÑÓÒÔÖÕÚÙÛÜÝŸÆŒ-]*[a-zA-Z0-9áàâäãåçéèêëíìîïñóòôöõúùûüýÿæœÁÀÂÄÃÅÇÉÈÊËÍÌÎÏÑÓÒÔÖÕÚÙÛÜÝŸÆŒ])?\.)+[a-zA-Z0-9áàâäãåçéèêëíìîïñóòôöõúùûüýÿæœÁÀÂÄÃÅÇÉÈÊËÍÌÎÏÑÓÒÔÖÕÚÙÛÜÝŸÆŒ](?:[a-zA-Z0-9áàâäãåçéèêëíìîïñóòôöõúùûüýÿæœÁÀÂÄÃÅÇÉÈÊËÍÌÎÏÑÓÒÔÖÕÚÙÛÜÝŸÆŒ-]*[a-zA-Z0-9áàâäãåçéèêëíìîïñóòôöõúùûüýÿæœÁÀÂÄÃÅÇÉÈÊËÍÌÎÏÑÓÒÔÖÕÚÙÛÜÝŸÆŒ])?)$)"#).unwrap(); let string = "jeu de test invalides ----------- a@123.123.123.123.123 a@123.123.123.123.5 a@222.333.666.888 a@322.111.222.001 a@29.99.352.001 a@124.124.14..124 a@a.f a@.fr adresse.de.321.caracteres@bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa@bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb.bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb.cccccccccc .bds@finances.gouv.fr.edu.com bds.@finances.gouv.fr.edu.com jeu de test valides ----------- a@222.111.11.2.tutu.com a@222.111.11.333.com a@222.111.com a@22d2.11d1.com a@29.99.252.001 a@022.111.222.001 a@124.124.124.124 a@111.111.111.111 a@222.5.22.001 této@194.168.12.5 abc@a.b.c.azertyuiop a@b.fr \"Abc@def\"@example.com def@example.com a@b.com abc@b.fr abc@a.b.c.fr abc@a.b.c.azertyuiop a@b.fr baltazar.da-silva@douane.finances.gouv.fr toto@titi.fr tôto@tïtié.fr \"tôto\"@tïtié.fr \"áàâäãåçéèêëíìîïñóòôöõúùûüýÿæÁÀÂÄÃÅÇÉÈÊËÍÌÎÏÑÓÒÔÖÕÚÙÛÜÝÆ\"@titiéà.fr \"této\"@titiéà.fr \"tàto\"@titiéà.fr \"t to\"@titiéà.fr této@titiéà.fr této@194.168.12.5 customer/department=shipping@example.com $A12345@example.com !def!xyz%abc@example.com _somename@example.com Loïc.Accentué@voilà.fr3"; // result will be an iterator over tuples containing the start and end indices for each match in the string let result = regex.captures_iter(string); for mat in result { println!("{:?}", mat); } }

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 Rust, please visit: https://docs.rs/regex/latest/regex/