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#"^([[:digit:]]{1,3}\.[[:digit:]]{1,3}\.[[:digit:]]{1,3}\.[[:digit:]]{1,3}\s)([a-zA-Z0-9_.\[\]\(\)\-:\s]{1,})\s(ModSecurity:\sWarning.\s)([a-zA-Z0-9\"\/\_\.\[\]\(\)\-:\s]{1,})(\s\[severity "CRITICAL"\]\s)([a-zA-Z0-9\"\/\_\.\[\]\(\)\-:\s]{1,})\s("OWASP_CRS\/)"#).unwrap(); let string = "129.232.250.201 [Tue Apr 30 14:01:54 2019] [error] [pid 23850] apache2_util.c(271) [client 196.40.111.5:39554 ] - [client 196.40.111.5] ModSecurity: Warning. Matched phrase \"bin/bash\" at ARGS_NAMES:/bin/bash. [file \"/opt/modsecurity/owasp-modsecurity-crs/rules/REQUEST-932-APPLICATION-ATTACK-RCE.conf\"] [line \"503\"] [id \"932160\"] [msg \"Remote Command Execution: Unix Shell Code Found\"] [data \"Matched Data: bin/bash found within ARGS_NAMES:/bin/bash: /bin/bash\"] [severity \"CRITICAL\"] [ver \"OWASP_CRS/3.1.0\"] [tag \"application-multi\"] [tag \"language-shell\"] [tag \"platform-unix\"] [tag \"attack-rce\"] [tag \"OWASP_CRS/WEB_ATTACK/COMMAND_INJECTION\"] [tag \"WASCTC/WASC-31\"] [tag \"OWASP_TOP_10/A1\"] [tag \"PCI/6.5.2\"] [hostname \"dedi-staging15.jnb1.host-h.net\"] [uri \"/test/\"] [unique_id \"XMg5MoHo@skAAF0qGI4AAAAE\"]"; // 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/