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

r"
"
s

Test String

Code Generator

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"(?s)(.*\()").unwrap(); let string = "// API callback google.search.Search.apiary2387({ \"cursor\": { \"currentPageIndex\": 0, \"estimatedResultCount\": \"4490\", \"moreResultsUrl\": \"http://www.google.com/cse?oe=utf8&ie=utf8&source=uds&q=ssh&start=0&sort=&cx=013305635491195529773:0ufpuq-fpt0\", \"resultCount\": \"4,490\", \"searchResultTime\": \"0.22\", \"pages\": [ { \"label\": 1, \"start\": \"0\" }, { \"label\": 2, \"start\": \"1\" }, { \"label\": 3, \"start\": \"2\" }, { \"label\": 4, \"start\": \"3\" }, { \"label\": 5, \"start\": \"4\" }, { \"label\": 6, \"start\": \"5\" }, { \"label\": 7, \"start\": \"6\" }, { \"label\": 8, \"start\": \"7\" }, { \"label\": 9, \"start\": \"8\" }, { \"label\": 10, \"start\": \"9\" } ] }, \"context\": { \"title\": \"Pastebin Active\", \"total_results\": \"0\", \"facets\": [] }, \"results\": [ { \"GsearchResultClass\": \"GwebSearch\", \"cacheUrl\": \"http://www.google.com/search?q=cache:PBL2A25kpZoJ:pastebin.com\", \"clicktrackUrl\": \"https://www.google.com/url?q=http://pastebin.com/u/ssh&sa=U&ved=0ahUKEwiO4fjNpovMAhWBPxoKHYJXAS4QFggEMAA&client=internal-uds-cse&usg=AFQjCNHczEhDXdcUnRZhpArEeSiHfjwMJA\", \"content\": \"BitBucket - Backup your code in the cloud! Host unlimited private projects, for free\\n. SIGN UP takes 10 seconds, and it&#39;s free! Guest&nbsp;...\", \"contentNoFormatting\": \"BitBucket - Backup your code in the cloud! Host unlimited private projects, for free\\n. SIGN UP takes 10 seconds, and it's free! Guest ...\", \"formattedUrl\": \"pastebin.com/u/\\u003cb\\u003essh\\u003c/b\\u003e\", \"title\": \"\\u003cb\\u003eSsh&#39;s\\u003c/b\\u003e Pastebin - Pastebin.com\", \"titleNoFormatting\": \"Ssh's Pastebin - Pastebin.com\", \"unescapedUrl\": \"http://pastebin.com/u/ssh\", \"url\": \"http://pastebin.com/u/ssh\", \"visibleUrl\": \"pastebin.com\", \"richSnippet\": { \"cseImage\": { \"src\": \"http://pastebin.com/i/facebook.png\" }, \"metatags\": { \"fbAppId\": \"231493360234820\", \"ogTitle\": \"Ssh's Pastebin - Pastebin.com\", \"ogType\": \"article\", \"ogUrl\": \"http://pastebin.com/u/ssh\", \"ogImage\": \"http://pastebin.com/i/facebook.png\", \"ogSiteName\": \"Pastebin\", \"viewport\": \"width=device-width, maximum-scale=1.0, user-scalable=no\" } } } ] } );"; // 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/