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

/
/
g

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"web\.\d{1,}\s+\|\s+(\{|>)").unwrap(); let string = "10:50:46 AM web.2 | > creating redis session\",\"time\":\"2016-05-18T17:50:46.161Z\",\"v\":0} 10:50:46 AM web.3 | {\"name\":\"investor-webapp-registration\",\"hostname\":\"lasinvonboard101-prod.tlcinternal.com\",\"pid\":28296,\"level\":20,\"middleware\":\"cache-headers\",\"msg\":\"Loading middleware:: cache-headers\",\"time\":\"2016-05-18T17:50:46.172Z\",\"v\":0} 10:50:46 AM web.2 | {\"name\":\"investor-webapp-registration\",\"hostname\":\"lasinvonboard101-prod.tlcinternal.com\",\"pid\":28283,\"level\":40,\"msg\":\"LC-SESSION: set the secret for the session cookies in the config file, check lc-session config\",\"time\":\"2016-05-18T17:50:46.174Z\",\"v\":0} 10:50:46 AM web.3 | {\"name\":\"investor-webapp-registration\",\"hostname\":\"lasinvonboard101-prod.tlcinternal.com\",\"pid\":28296,\"level\":20,\"middleware\":\"client-id\",\"msg\":\"Loading middleware:: client-id\",\"time\":\"2016-05-18T17:50:46.175Z\",\"v\":0} 10:50:46 AM web.3 | {\"name\":\"investor-webapp-registration\",\"hostname\":\"lasinvonboard101-prod.tlcinternal.com\",\"pid\":28296,\"level\":20,\"middleware\":\"cookie-parser\",\"msg\":\"Loading middleware:: cookie-parser\",\"time\":\"2016-05-18T17:50:46.175Z\",\"v\":0} 10:50:46 AM web.3 | {\"name\":\"investor-webapp-registration\",\"hostname\":\"lasinvonboard101-prod.tlcinternal.com\",\"pid\":28296,\"level\":20,\"middleware\":\"guid\",\"msg\":\"Loading middleware:: guid\",\"time\":\"2016-05-18T17:50:46.175Z\",\"v\":0} 10:50:46 AM web.3 | {\"name\":\"investor-webapp-registration\",\"hostname\":\"lasinvonboard101-prod.tlcinternal.com\",\"pid\":28296,\"level\":20,\"middleware\":\"healthy\",\"msg\":\"Loading middleware:: healthy\",\"time\":\"2016-05-18T17:50:46.176Z\",\"v\":0} 10:50:46 AM web.2 | {\"name\":\"investor-webapp-registration\",\"hostname\":\"lasinvonboard101-prod.tlcinternal.com\",\"pid\":28283,\"level\":20,\"middleware\":\"sso\",\"msg\":\"Loading middleware:: sso\",\"time\":\"2016-05-18T17:50:46.177Z\",\"v\":0} 10:50:46 AM web.2 | {\"name\":\"investor-webapp-registration\",\"hostname\":\"lasinvonboard101-prod.tlcinternal.com\",\"pid\":28283,\"level\":30,\"msg\":\"SSO-MIDDLEWARE: Detecting SSO config\",\"time\":\"2016-05-18T17:50:46.177Z\",\"v\":0} 10:50:46 AM web.2 | {\"name\":\"investor-webapp-registration\",\"hostname\":\"lasinvonboard101-prod.tlcinternal.com\",\"pid\":28283,\"level\":30,\"msg\":\"SSO-MIDDLEWARE: enabling JANUS-SSO\",\"time\":\"2016-05-18T17:50:46.179Z\",\"v\":0} 10:50:46 AM web.2 | {\"name\":\"investor-webapp-registration\",\"hostname\":\"lasinvonboard101-prod.tlcinternal.com\",\"pid\":28283,\"level\":20,\"middleware\":\"timer\",\"msg\":\"Loading middleware:: timer\",\"time\":\"2016-05-18T17:50:46.180Z\",\"v\":0} 10:50:46 AM web.1 | {\"name\":\"investor-webapp-registration\",\"hostname\":\"lasinvonboard101-prod.tlcinternal.com\",\"pid\":28278,\"level\":20,\"middleware\":\"cache-headers\",\"msg\":\"Loading middleware:: cache-headers\",\"time\":\"2016-05-18T17:50:46.180Z\",\"v\":0} 10:50:46 AM web.2 | {\"name\":\"investor-webapp-registration\",\"hostname\":\"lasinvonboard101-prod.tlcinternal.com\",\"pid\":28283,\"level\":20,\"middleware\":\"setTrackingData\",\"msg\":\"Loading middleware:: setTrackingData\",\"time\":\"2016-05-18T17:50:46.181Z\",\"v\":0} 10:50:46 AM web.1 | {\"name\":\"investor-webapp-registration\",\"hostname\":\"lasinvonboard101-prod.tlcinternal.com\",\"pid\":28278,\"level\":20,\"middleware\":\"client-id\",\"msg\":\"Loading middleware:: client-id\",\"time\":\"2016-05-18T17:50:46.181Z\",\"v\":0} 10:50:46 AM web.1 | {\"name\":\"investor-webapp-registration\",\"hostname\":\"lasinvonboard101-prod.tlcinternal.com\",\"pid\":28278,\"level\":20,\"middleware\":\"cookie-parser\",\"msg\":\"Loading middleware:: cookie-parser\",\"time\":\"2016-05-18T17:50:46.181Z\",\"v\":0} 10:50:46 AM web.1 | {\"name\":\"investor-webapp-registration\",\"hostname\":\"lasinvonboard101-prod.tlcinternal.com\",\"pid\":28278,\"level\":20,\"middleware\":\"guid\",\"msg\":\"Loading middleware:: guid\",\"time\":\"2016-05-18T17:50:46.181Z\",\"v\":0} 10:50:42 AM haproxy.1 | [WARNING] 138/105042 (28265) : Server nodes/node5001 is DOWN, reason: Layer4 connection problem, info: \"Connection refused\", check duration: 0ms. 2 active and 0 backup servers left. 0 sessions active, 0 requeued, 0 remaining in queue. 10:50:42 AM web.1 | warn: --minUptime not set. Defaulting to: 1000ms 10:50:42 AM web.1 | warn: --spinSleepTime not set. Your script will exit if it does not stay up for at least 1000ms 10:50:42 AM web.2 | warn: --minUptime not set. Defaulting to: 1000ms 10:50:42 AM web.2 | warn: --spinSleepTime not set. Your script will exit if it does not stay up for at least 1000ms 10:50:42 AM web.3 | warn: --minUptime not set. Defaulting to: 1000ms 10:50:42 AM web.3 | warn: --spinSleepTime not set. Your script will exit if it does not stay up for at least 1000ms 10:50:42 AM haproxy.1 | [WARNING] 138/105042 (28265) : Server nodes/node5002 is DOWN, reason: Layer4 connection problem, info: \"Connection refused\", check duration: 0ms. 1 active and 0 backup servers left. 0 sessions active, 0 requeued, 0 remaining in queue. 10:50:42 AM web.4 | warn: --minUptime not set. Defaulting to: 1000ms 10:50:42 AM web.4 | warn: --spinSleepTime not set. Your script will exit if it does not stay up for at least 1000ms 10:50:43 AM haproxy.1 | [WARNING] 138/105043 (28265) : Server nodes/node5003 is DOWN, reason: Layer4 connection problem, info: \"Connection refused\", check duration: 0ms. 0 active and 0 backup servers left. 0 sessions active, 0 requeued, 0 remaining in queue. 10:50:43 AM haproxy.1 | [ALERT] 138/105043 (28265) : backend 'nodes' has no server available! 10:50:43 AM web.2 | {\"name\":\"investor-webapp-registration\",\"hostname\":\"lasinvonboard101-prod.tlcinternal.com\",\"pid\":28283,\"level\":30,\"msg\":\"starting server on port 5001\",\"time\":\"2016-05-18T17:50:43.751Z\",\"v\":0}"; // 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/