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

/
/
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 = "\\[?(?<time>20\\d\\d-\\d\\d-\\d\\d\\s*\\d\\d:\\d\\d:\\d\\d(?:\\,|\\.)\\d+)\\[?"; final String string = "Apr 19 09:21:12 XYZADMXYZAB3P04 XYZADMXYZAB3P04 [customer] [426426|TaskExecutor-master-426426-ProcessTask [8797404726198]] [2018-04-19 09:21:11,929] [not present] [admin] [true]: Customer [aubcdsatest@google.com] is created/updated\n" + "Apr 25 15:00:44 XYZADMXYZAB3P04 XYZADMXYZAB3P04 [customer] [139468|TaskExecutor-master-139468-ProcessTask [8797864231862]] [2018-04-25 15:00:41,004] [not present] [admin] [true]: Customer [m.abcsree40@gmail.com] is created/updated\n" + "Apr 4 09:52:28 XYZECMXYZAB1P43 XYZECMXYZAB1P43 [customer] [103920|ajp-bio-8010-exec-158] [2018-04-04 09:52:21,843] [192.145.12.4] [line.sssss@icloud.com] [true]: Customer [lint.sre@icloud.com] is created/updated\n" + "Apr 4 09:52:28 XYZECMXYZAB1P43 XYZECMXYZAB1P43 [authentication] [103920|ajp-bio-8010-exec-158] [2018-04-04 09:52:21,876] [192.145.12.4] [abcd.sssss@icloud.com] [true]: user [abcd.ssss@icloud.com] successfully authenticated\n" + "Apr 9 12:41:52 XYZBUSXYZAB3P01 XYZBUSXYZAB3P01 [employee] [200061|hybrisHTTP8] [2018-04-09 12:41:48,609] [10.44.189.72] [anonymous] [true]: Employee [tester] is created/updated\n" + "Apr 21 02:55:46 ABCPUBXYZAB56 ABCPUBXYZAB56 2018-04-21 02:55:39.800 INFO [com.xyxf.auth.core.XYLoginHookAuthenticationHandler] Activated XYZ authentication feedback handler wrap handler enabled is true\n" + "Apr 12 08:23:06 ABCPUBXYZAB47 ABCPUBXYZAB47 2018-04-12 08:23:00.401 INFO [com.xyzf.auth.core.XYLoginHookAuthenticationHandler] 10.66.101.22 admin failed"; 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