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

// 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)^(?!MsgBox\().*(*SKIP)(*F)|(?:(?:.{1,70}|.{71,140}|.{141,210}|.{211,280})|\G(?!^))\S+\K\h(?=.{25,}$)").unwrap(); let string = "'Some looooooong comment Lorem ipsum dolor sit amet, consectetur adipiscing 'elit. Ut a volutpat dolor. In risus odio, pharetra a arcu in, efficitur 'ornare lectus. Maecenas non aliquet leo. Praesent luctus blandit 'magna, et sagittis ex porta et. MsgBox(\"Some text in MsgBox. Donec vulputate eros ac nulla hendrerit auctor. In hac habitasse platea dictumst. Proin fermentum augue elit, eget consequat massa mattis et. Integer semper imperdiet diam sit amet malesuada.\", 64, \"Title of MsgBox\") 'Another comment now with link to doc. 'https://example.com/?bs64=SWYgeW91IGFyZSBzbWFydCBlbm91Z2ggdG8gZGVjb2RlLCB5b3UgbXVzdCBkZWZpbml0ZWx5IHdhdGNoIHRoaXM6IGh0dHBzOi8vd3d3LnlvdXR1YmUuY29tL3dhdGNoP3Y9b0hnNVNKWVJIQTA="; let substitution = " \" _\\n & \""; // result will be a String with the substituted value let result = regex.replace_all(string, substitution); println!("{}", 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 Rust, please visit: https://docs.rs/regex/latest/regex/