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

/
/
gms

Test String

Code Generator

Language

Generated Code

import java.util.regex.Matcher; import java.util.regex.Pattern; public class Example { public static void main(String[] args) { final String regex = "^(\\w+) => (.*?)(?=(?:\\s^\\w+ =>|\\z))"; final String string = "processors => {\"models\"=>[\"AMD Opteron(tm) Processor 6172\", \"AMD Opteron(tm) Processor 6172\", \"AMD Opteron(tm) Processor 6172\", \"AMD Opteron(tm) Processor 6172\"], \"count\"=>4, \"physicalcount\"=>2}\n" + "productname => VMware Virtual Platform\n" + "ps => ps -ef\n" + "puppetversion => 3.6.2\n" + "rubysitedir => /usr/local/brs/harmony-puppet/lib/ruby/site_ruby/2.1.0\n" + "rubyversion => 2.1.2\n" + "sshecdsakey => AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBNDUmg8FQGCO/r/VGABUPwBqT8zTwzXwZCjTdBC6cXj1Mo5ypxuqO1Qtwg9uQagcS5eLNbv+SxHotpzYSXZ1R8g=\n" + "sshfp_dsa => SSHFP 2 1 42ffbd293f1501c0718b2b7b3852542329da1758\n" + "SSHFP 2 2 eb52d78a34bdadecc41b38366a5580c923bbb6cd0b81cec76de6379ce4251439\n" + "sshfp_ecdsa => SSHFP 3 1 d41abd2e3aff846b4efb59dbc8e4803875d33130\n" + "SSHFP 3 2 ae77a20a66859976e06efb7d6dd0819db4f9e9d93bc55da52a4bffff6acb1baa\n" + "sshfp_rsa => SSHFP 1 1 d3f14587683138e6d10cacba92fa34364ed5d326\n" + "SSHFP 1 2 132856925e056d02767e6c6ca4015ed21ac4c6eddb727f7c69e5edecb8806884\n" + "sshrsakey => AAAAB3NzaC1yc2EAAAADAQABAAABAQDzcJ6158aIkY161vcDH6WKNgKAeUsxrHh+HJH9IEistcV2TUJSdHtG/p5peI+cTa0EhabbNw8ToUU3ZWYmiTmxxuZzxggAxCx6xhWNDgC/492QnouxHnqjxwpFyIYnLpdbaMRV/6t9iE7v09Gfb31TS3/DbAUh5yla1OOeHbxJQ/eUOUYgy7/6eFL43+R9SfiuP11VRK8r325mCOFaPqw8VuNeGul/rMnccBCbuFvgmQnfOo/ldwrfOL2W4qAvfE0bKyG13WrDSlauo+CFtYqDK08hCItjrbVKgVrOzLCuKGzKFuqOgF3u8Q1je23qu7eUmF7lZPYVWSEpkh0xlR0p\n" + "swapfree => 1.45 GB\n" + "swapfree_mb => 1482.82\n" + "swapsize => 1.46 GB\n" + "swapsize_mb => 1497.00\n" + "system_uptime => {\"seconds\"=>6034301, \"hours\"=>1676, \"days\"=>69, \"uptime\"=>\"69 days\"}\n" + "timezone => PDT"; final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE | Pattern.DOTALL); final Matcher matcher = pattern.matcher(string); while (matcher.find()) { System.out.println("Full match: " + matcher.group(0)); for (int i = 1; i <= matcher.groupCount(); i++) { System.out.println("Group " + i + ": " + matcher.group(i)); } } } }

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 Java, please visit: https://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html