Regular Expressions 101

Save & Manage Regex

  • Current Version: 2
  • Save & Share
  • Community Library

Flavor

  • PCRE2 (PHP)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java
  • .NET 7.0 (C#)
  • Rust
  • PCRE (Legacy)
  • Regex Flavor Guide

Function

  • Match
  • Substitution
  • List
  • Unit Tests
Sponsors
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
Processing...

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"\b(\d{2})\/(\d{2})\/(\d{4})\s+(\d{2}):(\d{2}):(\d{2}).(\d{3})(\|\[*)\b").unwrap(); let string = "--- Output Example 1 SESSION|01/09/2017 15:35:42.143|[SFTP:1060257_0:it:10.87.16.71] WROTE: *150 Opening BINARY mode data connection. Ready to write file /it/cpp. \"/it/cpp\") S T O R* SESSION|01/09/2017 15:35:42.890|[SFTP:1060257_0:it:10.87.16.71] READ: *STOR END /it/cpp:PENs3* SESSION|01/09/2017 15:35:43.133|226-Upload File Size:1571846 bytes @ 1535K/sec. MD5=8438660f668ceb3de586cd7ef1263bc4 --- Output Example 2 SESSION|01/09/2017 15:35:42.143|[SFTP:1060257_0:it:10.87.16.71] WROTE: *150 Opening BINARY mode data connection. Ready to write file /it/cpp. \"/it/cpp\") S T O R* SESSION|01/09/2017 15:35:43.133|226-Upload File Size:1571846 bytes @ 1535K/sec. MD5=8438660f668ceb3de586cd7ef1263bc4 SESSION|01/09/2017 15:35:42.890|[SFTP:1060257_0:it:10.87.16.71] READ: *STOR END /it/cpp:PENs3* --- Output Example 3 - Overwrighting Existing files SESSION|12/20/2016 15:12:26.273|[SFTP:1008699_0:it:10.87.16.71] WROTE: *150 Opening BINARY mode data connection. Ready to write file /it/cpp. \"/it/cpp\") S T O R* SESSION|12/20/2016 15:12:26.299|226-Upload File Size:25 bytes @ 0K/sec. MD5=7e5e5560ab14904d5f5b2af5fcd8bec3 SESSION|12/20/2016 15:12:26.299|[SFTP:1008699_0:it:10.87.16.71] WROTE: *226 Transfer complete. MD5=7e5e5560ab14904d5f5b2af5fcd8bec3 (\"/it/cpp\" 25) STOR*"; // 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/