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"(?:opc.tcp|https|http):\/\/(\S+):\d+[\/\w]*").unwrap(); let string = "https://198.10.157.14:4814/fdggfh/fdhgdsf/gnhdfg opc.tcp://198.10.157.14:4814/fdggfh/fdhgdsf/gnhdfg address 192.168.1.1 netmask 255.255.255.0 gateway 192.168.1.254 =[\\w\\W]*(auto[\\w\\W]*eth2\\s+inet\\s+(dhcp|static)\\s*((?:address\\s+\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3})\\s+(?:netmask\\s+\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3})\\s+(?:gateway\\s+(\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3})))?) auto eth2 iface eth2 inet static address 192.168.1.1 netmask 255.255.255.0 gateway 192.168.1.254 pre-up /sbin/ifconfig $IFACE mtu 1450 auto eth3 iface eth3 inet static address 192.168.1.1 netmask 255.255.255.0 gateway 192.168.1.254 = ([\\d\\.]+)(\\w?)\\s+\\d+%.* /dev/sda1 ff 55 7sg233 fgd 3.7G 4.0K 3.7G 0% /mnt/sda1 <?xml version=\"1.0\" encoding= \"utf-8\"?> <confi guration> [\\w\\W]*(auto[\\w\\W]*eth2\\s+inet\\s+(dhcp|static)\\s+((?:address\\s+\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3})?\\s*(?:netmask\\s+\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3})?\\s*(?:gateway\\s+(\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}))?)?\\s+(pre-up \\/sbin\\/ifconfig \\$IFACE mtu \\d{3,4}\\s+))"; // 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/