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

Code Generator

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)^\[Error: +(?<source_path>(?<file>[^\s\n](?:[^\n:\\]+|\\.)+?)(?::(?<line>\d+)(?::(?<column>\d+)))?) *$").unwrap(); let string = "/usr/local/lib/node_modules/stylus/bin/stylus:685 throw err; ^ [Error: /Users/user/path/to/stylus/file/invalid.styl:34:5 30| ==/UserStyle== */ 31| 32| @-moz-document regexp(\"https?://(www\\\\.)?typescriptlang.org/(v2/)?docs.*$\"), 33| regexp(\"https?://(www\\\\.)?(staging-)?typescript\\\\.org/docs/.*$\") 34| error(\"compile error\") -----------^ 35| compile error ] { fromStylus: true, lineno: 34, column: 5, filename: '/Users/disk0/git.local/stylus-stylus/static/test/testFiles/invalid.styl', stylusStack: '', input: '/* ==UserStyle==\\n' + '@name TypeScript Docs\\n' + '@description Expands width of code blocks and moves navigation bar fully to the left\\n' + '@version 0.0.12\\n' + '@namespace github.com/disk0/stylus/typescript.org/docs\\n' + '\\n' + '@author disk0 (github.com/disco0)\\n' + '@license MIT\\n' + '\\n' + '@preprocessor stylus\\n' + '\\n' + '@var select CodeFont \"Font for code displayed on page.\" [\\n' + ' \"Iosevka Extended*\",\\n' + ' \"Iosevka Expanded\",\\n' + ' \"Iosevka Term\",\\n' + ' \"Iosevka\",\\n' + '\\n' + ' \"SemanticHaskell\",\\n' + ' \"SemanticJavascript\",\\n' + ' \"SemanticCode\",\\n' + ' \"Hasklig\",\\n' + '\\n' + ' \"PragmataPro Mono Liga\",\\n' + '\\n' + ' \"monospace\"\\n' + ']\\n' + '@var number CodeFontSize \"Size of code in documentation\" [ 14, 1, 500, 1, \"px\" ]\\n' + '@var number CodeFontWeight \"Code font weight\" [ 400, 100, 900, 100 ]\\n' + '@var number DocTextWidth \"Width of text content in documentation\" [ 1000, 300, 5000, 100, \"px\" ]\\n' + '==/UserStyle== */\\n' + '\\n' + '@-moz-document regexp(\"https?://(www\\\\\\\\.)?typescriptlang.org/(v2/)?docs.*$\"),\\n' + '\\t regexp(\"https?://(www\\\\\\\\.)?(staging-)?typescript\\\\\\\\.org/docs/.*$\")\\n' + ' error(\"compile error\")\\n' } "; // 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/