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

/
/
m

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 = "forward-zone:[.\\s]*name:[\\ \".\\s]*forward"; final String string = "## Simple recursive caching DNS, UDP port 53\n" + "## unbound.conf -- https://calomel.org\n" + "#\n" + "server:\n" + " access-control: 10.0.0.0/8 allow\n" + " access-control: 127.0.0.0/8 allow\n" + " access-control: 192.168.0.0/16 allow\n" + " cache-max-ttl: 14400\n" + " cache-min-ttl: 900\n" + " hide-identity: yes\n" + " hide-version: yes\n" + " interface: 0.0.0.0\n" + " minimal-responses: yes\n" + " prefetch: yes\n" + " qname-minimisation: yes\n" + " rrset-roundrobin: yes\n" + " use-caps-for-id: yes\n" + " verbosity: 1\n\n" + "forward-zone:\n" + " name: \".\"\n" + " forward-addr: 8.8.4.4 # Google\n" + " forward-addr: 8.8.8.8 # Google\n" + " forward-addr: 37.235.1.174 # FreeDNS\n" + " forward-addr: 37.235.1.177 # FreeDNS\n" + " forward-addr: 208.67.222.220 # OpenDNS\n" + " forward-addr: 208.67.222.222 # OpenDNS\n" + " forward-addr: 216.146.35.35 # Dyn Public\n" + " forward-addr: 216.146.36.36 # Dyn Public\n\n" + "forward-zone:\n" + " name: \"dns.com\"\n" + " forward-addr: 50.116.23.211 # OpenNIC\n" + " forward-addr: 64.6.64.6 # Verisign\n" + " forward-addr: 64.6.65.6 # Verisign\n" + " forward-addr: 74.82.42.42 # Hurricane Electric\n" + " forward-addr: 84.200.69.80 # DNS Watch\n" + " forward-addr: 84.200.70.40 # DNS Watch\n" + " forward-addr: 91.239.100.100 # censurfridns.dk\n" + " forward-addr: 109.69.8.51 # puntCAT\n"; final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE); final Matcher matcher = pattern.matcher(string); if (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