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
Processing...

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 = "^(?P<date>[^ ]+) (?P<time>[^ ]+) (?P<process_id>[^ ]+) (?P<level>[^ ]+) (?P<db>[^ ]+) (?P<app>[^:]+): (?P<message>(?P<ip>(?:[0-9]{1,3}\\.){3}[0-9]{1,3})(?: - - \\[[0-9]{2}\\/[A-Za-z]{3}\\/[0-9]{4}\\s[0-9]+:[0-9]+:[0-9]+\\] \")(?P<http>(?:[A-Z]+)) (?P<path>(?:[\\/a-z0-9\\._]*)) .*\" (?P<response>(?:\\d{3})) (?:-) (?P<http_size>\\d+) (?P<http_time_total>\\d+\\.\\d+) (?P<http_time_>\\d+\\.\\d+)|.*)$"; final String string = "2023-03-17 15:55:43,022 11272 INFO odoo werkzeug: 127.0.0.1 - - [17/Mar/2023 15:55:43] \"POST /web/action/load HTTP/1.0\" 200 - 27 0.028 0.047\n" + "2023-03-17 15:55:43,277 11272 INFO odoo werkzeug: 127.0.0.1 - - [17/Mar/2023 15:55:43] \"POST /web/dataset/call_kw/pos.session/load_views HTTP/1.0\" 200 - 88 0.059 0.121\n" + "2023-03-17 15:55:43,362 11272 DEBUG odoo odoo.modules.registry: Multiprocess signaling check: [Registry - 39 -> 39] [Cache - 65832 -> 65832] \n" + "2023-03-17 15:55:43,365 11272 DEBUG odoo odoo.api: call pos.config(3,).name_get()\n\n" + "2023-03-17 15:55:43,375 11272 INFO odoo werkzeug: 127.0.0.1 - - [17/Mar/2023 15:55:43] \"POST /web/dataset/call_kw/pos.config/name_get HTTP/1.0\" 200 - 7 0.004 0.013\n" + "2023-03-17 15:55:43,469 11272 DEBUG odoo odoo.modules.registry: Multiprocess signaling check: [Registry - 39 -> 39] [Cache - 65832 -> 65832] \n" + "2023-03-17 15:55:43,513 11272 INFO odoo werkzeug: 127.0.0.1 - - [17/Mar/2023 15:55:43] \"POST /web/dataset/search_read HTTP/1.0\" 200 - 10 0.010 0.037\n" + "2023-03-17 15:55:46,060 11272 INFO odoo werkzeug: 127.0.0.1 - - [17/Mar/2023 15:55:46] \"POST /longpolling/poll HTTP/1.0\" 200 - 9 0.006 50.025\n"; final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE | Pattern.CASE_INSENSITIVE); 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