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
  • Match everything enclosed
    (?:...)
  • Capture everything enclosed
    (...)
  • 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

/
/
mg

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"(?m)^([a-zA-Z]+):\/\/(-\.)?(([^\s\/?\.#\-]+|([^\s\/?\.#\-]-[^\s\/?\.#\-]))\.?)+(\/[^\s]*)?$").unwrap(); let string = "SHOULD MATCH: http://foo.com/blah_blah http://foo.com/blah_blah/ http://foo.com/blah_blah_(wikipedia) http://foo.com/blah_blah_(wikipedia)_(again) http://www.example.com/wpstyle/?p=364 https://www.example.com/foo/?bar=baz&inga=42&quux http://✪df.ws/123 http://userid:password@example.com:8080 http://userid:password@example.com:8080/ http://userid@example.com http://userid@example.com/ http://userid@example.com:8080 http://userid@example.com:8080/ http://userid:password@example.com http://userid:password@example.com/ http://142.42.1.1/ http://142.42.1.1:8080/ http://➡.ws/䨹 http://⌘.ws http://⌘.ws/ http://foo.com/blah_(wikipedia)#cite-1 http://foo.com/blah_(wikipedia)_blah#cite-1 http://foo.com/unicode_(✪)_in_parens http://foo.com/(something)?after=parens http://☺.damowmow.com/ http://code.google.com/events/#&product=browser http://j.mp ftp://foo.bar/baz http://foo.bar/?q=Test%20URL-encoded%20stuff http://مثال.إختبار http://例子.测试 http://उदाहरण.परीक्षा http://-.~_!$&'()*+,;=:%40:80%2f::::::@example.com http://1337.net http://a.b-c.de http://223.255.255.254 SHOULD NOT MATCH: http:// http://. http://.. http://../ http://? http://?? http://??/ http://# http://## http://##/ http://foo.bar?q=Spaces should be encoded // //a ///a /// http:///a foo.com rdar://1234 h://test http:// shouldfail.com :// should fail http://foo.bar/foo(bar)baz quux ftps://foo.bar http://-error-.invalid/ http://a.b--c.de/ http://-a.b.co http://a.b-.co http://0.0.0.0 http://10.1.1.0 http://10.1.1.255 http://224.1.1.1 http://1.1.1.1.1 http://123.123.123 http://3628126748 http://.www.foo.bar/ http://www.foo.bar./ http://.www.foo.bar./ http://10.1.1.1"; // 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/