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"Request\:\s\[(?P<req_ip>\d+\.\d+\.\d+\.\d+)").unwrap(); let string = "Jun 20, 2016 17:59:39 [0x7f16b541b700] DEBUG - Request: [192.168.1.88:54368] GET /:/timeline?ratingKey=68803&key=%2Flibrary%2Fmetadata%2F68803&state=paused&playQueueItemID=2831&time=1360507&duration=5694741 (34 live) TLS GZIP Jun 20, 2016 17:59:39 [0x7f16b541b700] DEBUG - Auth: We found auth token (xxxxxxxxxxxxxxxxxxxx), enabling token-based authentication. Jun 20, 2016 17:59:39 [0x7f16b541b700] DEBUG - Auth: Came in with a super-token, authorization succeeded. Jun 20, 2016 17:59:39 [0x7f16b541b700] DEBUG - Client [iqzupp52ref65urd69nng66r] reporting timeline state paused, progress of 1360507/5694741ms for guid=, ratingKey=68803 url=, key=/library/metadata/68803, containerKey=, metadataId=68803 Jun 20, 2016 17:59:39 [0x7f16b541b700] DEBUG - Play progress on 68803 'Kung Fu Panda 3' - got played 1360507 ms by account 1! Jun 20, 2016 17:59:39 [0x7f16b541b700] DEBUG - [Now] User is sydvishus (ID: 1) Jun 20, 2016 17:59:39 [0x7f16b541b700] DEBUG - [Now] Device is Chrome (Plex Web (Chrome)). Jun 20, 2016 17:59:39 [0x7f16b541b700] DEBUG - [Now] Updated play state for /library/metadata/68803. Jun 20, 2016 17:59:39 [0x7f16c1bff700] DEBUG - Completed: [192.168.1.88:54368] GET /:/timeline?ratingKey=68803&key=%2Flibrary%2Fmetadata%2F68803&state=paused&playQueueItemID=2831&time=1360507&duration=5694741 (34 live) TLS GZIP 4ms 276 bytes 200 (pipelined: 20)"; // 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/