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"<[^>]*>").unwrap(); let string = "</style></head><body dir=\"ltr\" style=\"max-width:21cm;margin-top:1cm; margin-bottom:1cm; margin-left:1cm; margin-right:1cm; \"> <p class=\"P11\">PRE-REGISTRATION</p> <p class=\"P11\">FIL_RI_CHOP</p> <p class=\"P1\"><span class=\"T3\">We confirm the completion of the pre-registration CRF for the patient <span class=\"T1\">1</span> enrolled in the study <span class=\"T1\">FIL_RI_CHOP</span>.</span><a id=\"_GoBack\"/><span class=\"T1\"></span></p> <p class=\"P1\"> <span class=\"T3\">Date: </span><span class=\"T1\">2018-08-03<br/></span> <span class=\"T3\">Patient's Code: </span><span class=\"T1\">1<br/></span> <span class=\"T3\">Center: </span><span class=\"T1\">17_Terni_S.Maria<br/></span> <span class=\"T3\">User: </span><span class=\"T1\">site_admin<br/></span></p><p class=\"P1\"> <span class=\"T3\">Uffici Studi FIL</span></p><p class=\"P1\"> <span class=\"T3\">Fondazione Italiana Linfomi ONLUS</span></p>"; // 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/