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
Processing...

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#"(?s)^.{4}[-"$%&*+:;=?{}a-zMZ]+.{4}$"#).unwrap(); let string = "<?=\"\";$cr=\"M\"&\"-\";$cr=\"Z\"&\"*\";$zero=$one=$line=$text=\"\";$zero++;$zero--;$a=$zero;s=\"$zero\"&\"$\";$one=++$one;$five=$one+$one+$one+$one+$one;$ten=$five+$five;${\"v$zero\"}=\"$s$s$s$s$s$s$s\";${\"v$one\"}=\"$s$s$s$s$s$s\";${\"v$ten\"}=\"$s$s$s$s$s\";$g=$argc-$one;$g=$argv{$one};$space=$zero;$p=${\"v$space\"};$dir=$one;a:++$a;$a%$ten?:$space++;$p=${\"v$space\"}??$p;$line=$dir?\"$line$a\":\"$a$line\";$line=$a%$g?$dir?\"$line$p\":\"$p$line\":\"$line$cr\";$dir=$a%$g?$dir:$one-$dir;$text=$a%$g?$text:\"$text$line\";$line=$a%$g?$line:\"\";echo$a-$g*$g?\"\":$text;$a-$g*$g?:exit;goto a?>"; // 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/