Regular Expressions 101

Save & Share

  • Regex Version: ver. 1
  • Update Regex
    ctrl+⇧+s
  • Save new Regex
    ctrl+s
  • Add to Community Library

Flavor

  • PCRE2 (PHP >=7.3)
  • PCRE (PHP <7.3)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java 8
  • .NET 7.0 (C#)
  • Rust
  • Regex Flavor Guide

Function

  • Match
  • Substitution
  • List
  • Unit Tests

Tools

Sponsors
There are currently no sponsors. Become a sponsor today!
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

/
/
mg

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#"(?m)^([\d.]+) (\S+) (\S+) \[([\w:\/]+\s[+\-]\d{4})\] "GET (.+?) HTTP\/1\.1" (\d{3}) (\d+) "([^"]+)" "([^"]+)""#).unwrap(); let string = "79.133.215.123 - - [14/Jun/2014:10:30:13 -0400] \"GET /home HTTP/1.1\" 200 1671 \"-\" \"Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/35.0.1916.153 Safari/537.36\" 162.235.161.200 - - [14/Jun/2014:10:30:13 -0400] \"GET /department/apparel/category/featured%20shops/product/adidas%20Kids'%20RG%20III%20Mid%20Football%20Cleat HTTP/1.1\" 200 1175 \"-\" \"Mozilla/5.0 (Macintosh; Intel Mac OS X 10_9_3) AppleWebKit/537.76.4 (KHTML, like Gecko) Version/7.0.4 Safari/537.76.4\" 39.244.91.133 - - [14/Jun/2014:10:30:14 -0400] \"GET /department/fitness HTTP/1.1\" 200 1435 \"-\" \"Mozilla/5.0 (Macintosh; Intel Mac OS X 10_9_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/35.0.1916.153 Safari/537.36\" 150.47.54.136 - - [14/Jun/2014:10:30:14 -0400] \"GET /department/fan%20shop/category/water%20sports/product/Pelican%20Sunstream%20100%20Kayak/add_to_cart HTTP/1.1\" 200 1932 \"-\" \"Mozilla/5.0 (Macintosh; Intel Mac OS X 10_9_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/35.0.1916.153 Safari/537.36\" 217.89.36.129 - - [14/Jun/2014:10:30:14 -0400] \"GET /view_cart HTTP/1.1\" 200 1401 \"-\" \"Mozilla/5.0 (Windows NT 6.1; WOW64; rv:30.0) Gecko/20100101 Firefox/30.0\" 36.44.59.115 - - [14/Jun/2014:10:30:15 -0400] \"GET /department/footwear/category/cardio%20equipment HTTP/1.1\" 200 386 \"-\" \"Mozilla/5.0 (Windows NT 6.1; WOW64; rv:30.0) Gecko/20100101 Firefox/30.0\" 11.252.83.179 - - [14/Jun/2014:10:30:15 -0400] \"GET /view_cart HTTP/1.1\" 200 1726 \"-\" \"Mozilla/5.0 (Macintosh; Intel Mac OS X 10_9_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/35.0.1916.153 Safari/537.36\" 56.251.19.230 - - [14/Jun/2014:10:30:15 -0400] \"GET /department/footwear/category/fitness%20accessories HTTP/1.1\" 200 2076 \"-\" \"Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/35.0.1916.153 Safari/537.36\" 137.95.229.186 - - [14/Jun/2014:10:30:16 -0400] \"GET /department/fan%20shop/category/fishing/product/Field%20&%20Stream%20Sportsman%2016%20Gun%20Fire%20Safe HTTP/1.1\" 200 1413 \"-\" \"Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/35.0.1916.153 Safari/537.36\" 100.98.159.99 - - [14/Jun/2014:10:30:16 -0400] \"GET /department/fan%20shop/category/water%20sports/product/Pelican%20Sunstream%20100%20Kayak HTTP/1.1\" 200 396 \"-\" \"Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/35.0.1916.153 Safari/537.36\" 137.95.229.186 - - [14/Jun/2014:10:30:16 -0400] \"GET /home HTTP/1.1\" 200 1473 \"-\" \"Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/35.0.1916.153 Safari/537.36\" 86.214.1.70 - - [14/Jun/2014:10:30:17 -0400] \"GET /department/fan%20shop HTTP/1.1\" 200 771 \"-\" \"Mozilla/5.0 (Macintosh; Intel Mac OS X 10_9_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/36.0.1985.125 Safari/537.36\" 18.168.113.227 - - [14/Jun/2014:10:30:17 -0400] \"GET /support HTTP/1.1\" 200 1321 \"-\" \"Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/35.0.1916.153 Safari/537.36\" 133.20.136.170 - - [14/Jun/2014:10:30:18 -0400] \"GET /home HTTP/1.1\" 200 1238 \"-\" \"Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/35.0.1916.153 Safari/537.36\" 137.95.229.186 - - [14/Jun/2014:10:30:18 -0400] \"GET /home HTTP/1.1\" 200 1797 \"-\" \"Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/35.0.1916.153 Safari/537.36\" 100.158.186.50 - - [14/Jun/2014:10:30:18 -0400] \"GET /home HTTP/1.1\" 200 878 \"-\" \"Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/35.0.1916.153 Safari/537.36\" 36.44.59.115 - - [14/Jun/2014:10:30:19 -0400] \"GET /checkout HTTP/1.1\" 200 1551 \"-\" \"Mozilla/5.0 (Windows NT 6.1; WOW64; Trident/7.0; rv:11.0) like Gecko\" "; // 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/