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"^(?<time>.+?)\s+(?<logname>.+?)\s+(?<log>.+?)$").unwrap(); let string = "2023-02-06T08:09:46+00:00 kubernetes.var.log.containers.app-test-app-test-space-fb5ffca1ec-0_cf-workloads_opi-05942675f9f0dd17039304733f228e7abd6ebdfd91609baf1a7afefaeb33ced8.log {\"stream\":\"stdout\",\"log\":\"Console output from test-node-app\",\"docker\":{\"container_id\":\"05942675f9f0dd17039304733f228e7abd6ebdfd91609baf1a7afefaeb33ced8\"},\"kubernetes\":{\"container_name\":\"opi\",\"namespace_name\":\"cf-workloads\",\"pod_name\":\"app-test-app-test-space-fb5ffca1ec-0\",\"pod_id\":\"f4f2592e-ed57-4375-aff7-40c7b214abe0\",\"host\":\"ap-joy-sidecar-5\",\"labels\":{\"controller-revision-hash\":\"app-test-app-test-space-fb5ffca1ec-5bb7dc5769\",\"cloudfoundry_org/app_guid\":\"8fc07280-506c-49b2-ab00-a97222fcf0a5\",\"cloudfoundry_org/guid\":\"8fc07280-506c-49b2-ab00-a97222fcf0a5\",\"cloudfoundry_org/org_guid\":\"fdf0a222-33a4-46fd-a7f9-7955b9ea862c\",\"cloudfoundry_org/org_name\":\"system\",\"cloudfoundry_org/process_type\":\"web\",\"cloudfoundry_org/source_type\":\"APP\",\"cloudfoundry_org/space_guid\":\"f1b70a4b-7581-4214-b128-2f1597f7789d\",\"cloudfoundry_org/space_name\":\"app-test-space\",\"cloudfoundry_org/version\":\"ebfde654-e73c-48da-b55b-42a37a6ba139\",\"security_istio_io/tlsMode\":\"istio\",\"service_istio_io/canonical-name\":\"app-test-app-test-space-fb5ffca1ec\",\"service_istio_io/canonical-revision\":\"latest\",\"statefulset_kubernetes_io/pod-name\":\"app-test-app-test-space-fb5ffca1ec-0\"}},\"app_id\":\"8fc07280-506c-49b2-ab00-a97222fcf0a5\",\"instance_id\":\"f4f2592e-ed57-4375-aff7-40c7b214abe0\",\"structured_data\":\"[tags@47450 source_type=\\\"APP/PROC/WEB\\\"]\"} "; // 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/