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"-*\nRuntime error\n*User: (?<User>\w.+)\nDomain: (?<Domain>\w.+)\nURI: (?<uri>\/?\w.+)\nReferer: (?<referer>\w.+)\nAgent: (?<agent>\w.+)\n.+\n.+\nweb.Server Traceback \(most recent call last\):\n(?<trace>.(.|\n)*)").unwrap(); let string = "------------------------------------------------- Runtime error User: Dr. AkomaDr (896) Domain: staging-app.clickmedix.com URI: /users/profile_edit Referer: https://staging-app.clickmedix.com/akomapa/users/profile_edit Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/50.0.2661.102 Safari/537.36 Params: {} web.Server Traceback (most recent call last): [Failure instance: Traceback: <type 'exceptions.ZeroDivisionError'>: integer division or modulo by zero /srv/click/shared/virtualenv/lib/python2.7/site-packages/twisted/web/http.py:1349:dataReceived /srv/click/shared/virtualenv/lib/python2.7/site-packages/twisted/web/http.py:1563:_finishRequestBody /srv/click/shared/virtualenv/lib/python2.7/site-packages/twisted/web/http.py:1618:allContentReceived /srv/click/shared/virtualenv/lib/python2.7/site-packages/twisted/web/http.py:773:requestReceived --- <exception caught here> --- /srv/click/shared/virtualenv/lib/python2.7/site-packages/twisted/web/server.py:131:process /srv/click/shared/virtualenv/lib/python2.7/site-packages/twisted/web/server.py:562:getResourceFor /srv/click/shared/virtualenv/lib/python2.7/site-packages/twisted/web/resource.py:65:getChildForRequest /srv/click/shared/virtualenv/src/warp/warp/webserver/resource.py:208:getChildWithDefault /srv/click/current/util/helpers.py:78:getResponse /srv/click/current/nodes/users/users.py:255:render_profile_edit"; // 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/