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

/
/
gx

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#"(?x)(,\s*(*SKIP))?+ # Attempts to match a comma and advanced whitespaces, # without backtracking; # And if the comma is matched, use (*SKIP) verb, # which advances the pointer if we fail to match the comma. # Key - Value pairs not worthy of keeping. ( "(?!jobID"|exec)[^"]+" # Check if we like this key. \s*+:\s*+ # The colon, advance whitespaces. ( # Check keys recursively. "[^"]*" # String literals, boring. | {(?2)?+(?>,\s*(?2))*} # Or: An object storing some key-value pairs # we don't care about. | \[(?3)?+(?>,\s*(?3))*\] # Or: An array storing some values # we don't care about. ) ) (?(1)|,?) # Balance the comma (so the result string is still valid JSON)"#).unwrap(); let string = " \"2597401\":[{\"jobID\":\"2597401\", \"account\":\"TG-CCR120014\", \"user\":\"charngda\", \"pkgT\":{\"pgi/7.2- 5\":{\"libA\":[\"libpgc.so\"], \"flavor\":[\"default\"]}}, \"startEpoch\":\"1338497979\", \"runTime\":\"1022\", \"execType\":\"user:binary\", \"exec\":\"ft.D.64\", \"numNodes\":\"4\", \"sha1\":\"5a79879235aa31b6a46e73b43879428e2a175db5\", \"execEpoch\":1336766742, \"execModify\":\"Fri May 11 15:05:42 2012\", \"startTime\":\"Thu May 31 15:59:39 2012\", \"numCores\":\"64\", \"sizeT\":{\"bss\":\"1881400168\",\"text\":\"239574\",\"data\":\"22504\"}}, {\"jobID\":\"2597401\", \"account\":\"TG-CCR120014\", \"user\":\"charngda\", \"pkgT\":{\"pgi/7.2-5\":{\"libA\":[\"libpgc.so\"], \"flavor\":[\"default\"]}}, \"startEpoch\":\"1338497946\", \"runTime\":\"33\" \"execType\":\"user:binary\", \"exec\":\"cg.C.64\", \"numNodes\":\"4\", \"sha1\":\"caf415e011e28b7e4e5b050fb61cbf71a62a9789\", \"execEpoch\":1336766735, \"execModify\":\"Fri May 11 15:05:35 2012\", \"startTime\":\"Thu May 31 15:59:06 2012\", \"numCores\":\"64\", \"sizeT\":{\"bss\":\"29630984\",\"text\":\"225749\",\"data\":\"20360\"}}, {\"jobID\":\"2597401\", \"account\":\"TG-CCR120014\", \"user\":\"charngda\", \"pkgT\":{\"pgi/7.2-5\": {\"libA\":[\"libpgc.so\"], \"flavor\":[\"default\"]}}, \"startEpoch\":\"1338500447\", \"runTime\":\"145\", \"execType\":\"user:binary\", \"exec\":\"mg.D.64\", \"numNodes\":\"4\", \"sha1\":\"173de32e1514ad097b1c051ec49c4eb240f2001f\", \"execEpoch\":1336766756, \"execModify\":\"Fri May 11 15:05:56 2012\", \"startTime\":\"Thu May 31 16:40:47 2012\", \"numCores\":\"64\", \"sizeT\":{\"bss\":\"456954120\",\"text\":\"426186\",\"data\":\"22184\"}},{\"jobID\":\"2597401\", \"account\":\"TG-CCR120014\", \"user\":\"charngda\", \"pkgT\":{\"pgi/7.2-5\":{\"libA\":[\"libpgc.so\"], \"flavor\":[\"default\"]}}, \"startEpoch\":\"1338499002\", \"runTime\":\"1444\", \"execType\":\"user:binary\", \"exec\":\"lu.D.64\", \"numNodes\":\"4\", \"sha1\":\"c6dc16d25c2f23d2a3321d4feed16ab7e10c2cc1\", \"execEpoch\":1336766748, \"execModify\":\"Fri May 11 15:05:48 2012\", \"startTime\":\"Thu May 31 16:16:42 2012\", \"numCores\":\"64\", \"sizeT\":{\"bss\":\"199850984\",\"text\":\"474218\",\"data\":\"27064\"}}],"; // 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/