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

/
/

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"Instrument Method\s*[=:-]\s*(?<dm>.*)").unwrap(); let string = "This data was acquired in Method&Run Control. The MSD parameters were saved in the msdiag register file. This msparms.txt file was built using the values from the msdiag register. Some parameters normally reported under MSData acquisition in Tune may be missing from this msparms.txt file. You may be able to read these values from Data Analysis. These items are marked with an asterisk (*). File : C:\\HPCHEM\\1\\DATA\\FIA.D Operator : Apps Chemist Date acquired : Wed Apr 09 17:50:26 1997 Instrument Method : Appsprite2 Sample information ---------------------------------- Sample name : 50 ng caffeine Misc info : 50 ng Caffeine run in condensed mode varying fragmentor MS parameters ---------------------------------- Tune File : C:\\HPCHEM\\1\\1946TUNE\\atunes.tun Skim1 : Not Applicable Skim2 : 8.0 V Ion Energy : 5.0 V Lens1 : 1.4 V Lens2 : 27 V Iris : 350 V HED : 10000 V Width Gain : -70 Width Offset : Variable Mass : Value -------------------------- 118.10 : -11 622.03 : -14 922.01 : -2 1521.97 : -8 2121.93 : -13 2721.89 : -12 -------------------------- Mass Gain : 4.40 Mass Offset : Variable Mass : Value -------------------------- 118.10 : 0 622.03 : 0 922.01 : 0 1521.97 : 0 2121.93 : 0 2721.89 : 0 -------------------------- Quad DC : 0.00 V Octopole Peak : 300 V Octopole Knee : 307 Da Mass Filter : Gaussian Mass Filter Width : 0.30 Da "; // result will be a tuple containing the start and end indices for the first match in the string let result = regex.captures(string); let (start, end) = match result { Some((s, e)) => (s, e), None => { // ... } }; println!("{}", &string[start, 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 Rust, please visit: https://docs.rs/regex/latest/regex/