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

r"
"
gm

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 = "^(.+ESTABLISHED[\\s\\S]+?={3}.+?)$"; final String string = "Security Associations (2 up, 0 connecting):\n" + " IPSec-IKEv2[2]: ESTABLISHED 10 seconds ago, 5.79.70.34[a.teletom.ru]...91.77.160.189[192.168.1.64]\n" + " IPSec-IKEv2[2]: Remote EAP identity: mac\n" + " IPSec-IKEv2[2]: IKEv2 SPIs: 8e03bee2f90a7b0f_i 2b840459b2a53517_r*, rekeying disabled\n" + " IPSec-IKEv2[2]: IKE proposal: AES_CBC_256/HMAC_SHA2_256_128/PRF_HMAC_SHA2_256/MODP_2048\n" + " IPSec-IKEv2{2}: INSTALLED, TUNNEL, reqid 2, ESP in UDP SPIs: ca7323ca_i 0dd681eb_o\n" + " IPSec-IKEv2{2}: AES_CBC_128/HMAC_SHA1_96, 63234 bytes_i (390 pkts, 0s ago), 113714 bytes_o (345 pkts, 0s ago), rekeying disabled\n" + " IPSec-IKEv2{2}: 0.0.0.0/0 === 10.101.0.2/32\n" + " IPSec-IKEv2[1]: ESTABLISHED 8 minutes ago, 5.79.70.34[a.teletom.ru]...91.77.160.189[hon]\n" + " IPSec-IKEv2[1]: IKEv2 SPIs: 0fa1c950bdb21ac0_i 0bcd0f3b2bea4cea_r*, rekeying disabled\n" + " IPSec-IKEv2[1]: IKE proposal: AES_CBC_128/HMAC_SHA2_256_128/PRF_HMAC_SHA2_256/ECP_256\n" + " IPSec-IKEv2{1}: INSTALLED, TUNNEL, reqid 1, ESP in UDP SPIs: cb680131_i 69774a81_o\n" + " IPSec-IKEv2{1}: AES_GCM_16_128, 86593 bytes_i (454 pkts, 11s ago), 249805 bytes_o (510 pkts, 11s ago), rekeying disabled\n" + " IPSec-IKEv2{1}: 0.0.0.0/0 === 10.101.0.1/32"; final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE); 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