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"(?mx)( # start capture url (?:(?:(?:ht|f)tps?\:)\/\/?|(?:www\.)) # start with http or www (?:\s?[:\w?=%&+-]+ # need some chars in url, allow spaces. (?:(?:(?:\.)|(?:\/(?:\/)?)))? # can have ., / or // inside urls. )+ # allow repeat alternating pattern of chars and delimiters ) # end capture url").unwrap(); let string = "http://www.apple.com/legal/ privacy/. abbbbbbbbbbbb abababab aaab hi h123213i.what let's do some URLs next segment> https://duckduckgo.com/?q=perl+regex+%2Fmxsp&t=canonical&atb=v143-1&ia=web, http://www.rexegg.com/regex-modifiers.html <segment hi there segment> https://duckduckgo.com/?q=tutorial+perl+regex+substitution+capture+groups&t=canonical&atb=v143-1&ia=web-https://regex101.com/, www.giggle.com B. Privacy Policy. At all times your information will be treated in accordance with Apple’s Privacy Policy, which is incorporated by reference into this License and can be viewed at: http://www.apple.com/legal/ privacy/. qweqweqwewqe www.howdy.com/welcome::&5"; // 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/