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

/
/

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#"flavor=\"[^\"]+\(([^\)]+)"#).unwrap(); let string = "<182>1 2016-08-30T13:11:17.530157+02:00 cloudcapprorh01.boaweng.gsnetcloud.corp capacity.instances - - [timeQuality tzKnown=\"1\" isSynced=\"1\" syncAccuracy=\"946892\"] diskconfig=\"MANUAL\" availability_zone=\"BOAW-1\" host=\"srvboaw01cnodep38.boaw-infra.gsnetcloud.corp\" hypervisor_hostname=\"srvboaw01cnodep38.boaw-infra.gsnetcloud.corp\" instance_name=\"inst-00001ff5\" power_state=\"1\" task_state=\"None\" vm_state=\"active\" launched_at=\"2015-07-23T07:18:03.000000\" terminated_at=\"None\" accessipv4=\"\" accessipv6=\"\" addresses=\"PRB_PRODSERV_LAB (Template 0) \\ Subnet 0=10.200.0.16\" config_drive=\"\" created=\"2015-07-23T07:17:59Z\" flavor=\"sabor554??(adf) (1003)\" hostid=\"76651d2e4c981ab8084dad155e52129580ed9fd4baf5fa628cd8bae8\" id=\"61626999-026e-4d06-9eaa-835c0262b939\" image=\"RHEL 7.0 (3fa495a8-fbb6-45c0-9c44-874b9016d4a3)\" key_name=\"jdelarco\" name=\"gitlab\" volumes_attached=\"[]\" progress=\"0\" project_id=\"6e58b12be4bb4972bfb42812ee806065\" properties=\"\" security_groups=\"[{u'name': u'default'}]\" status=\"ACTIVE\" updated=\"2015-11-16T17:06:38Z\" user_id=\"x100183\" region=BOAW"; // 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/