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 = "(?P<query_date>\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}Z UTC) \\[ db=(?P<db>\\w+) LOG:(?P<query_text>[\\w|\\W]*?;)"; final String string = "'2021-06-23T08:02:08Z UTC [ db=dev LOG: BEGIN;\n" + "'2021-06-23T08:02:08Z UTC [ db=dev LOG: SET datestyle TO ISO;\n" + "'2021-06-23T08:02:08Z UTC [ db=dev LOG: SET TRANSACTION READ ONLY;\n" + "'2021-06-23T08:02:08Z UTC [ db=dev LOG: SET STATEMENT_TIMEOUT\n" + " TO 300000;\n" + "'2021-06-23T08:02:08Z UTC [ LOG: /* hash: 8d9692aa66628f2ea5b0b9de8e4ea59b */\n\n" + "SELECT action,\n" + " status,\n" + " COUNT(*) AS num_req\n" + "FROM stl_datashare_changes_consumer\n" + "WHERE actiontime > getdate() - INTERVAL '1 day'\n" + "GROUP BY 1,2;\n" + "'2021-06-23T08:02:08Z UTC [ LOG: SELECT pg_catalog.stll_datashare_changes_consumer.action AS action, pg_catalog.stll_datashare_changes_consumer.status AS status, COUNT(*) AS num_req FROM pg_catalog.stll_datashare_changes_consumer WHERE pg_catalog.stll_datashare_changes_consumer.actiontime > getdate() - interval '1 day'::Interval GROUP BY 1, 2;\n" + "'2021-06-23T08:02:08Z UTC [ LOG: COMMIT;\n" + "'2021-06-23T08:02:08Z UTC [ LOG: SET query_group to ''\n" + "'2021-06-23T08:02:22Z UTC [ LOG: SELECT 1\n" + "'2021-06-23T08:02:30Z UTC [ LOG: /* hash: 64f5dca78e917617f51632257854cb2f */\n" + "WITH per_commit_info AS\n" + "(\n" + " SELECT date_trunc('day', startwork) AS day,\n" + " c.xid,\n" + " SUM(num_metadata_blocks_retained) AS sum_retained,\n" + " SUM(total_metadata_blocks) AS sum_total,\n" + " AVG(num_metadata_blocks_retained) AS avg_retained,\n" + " AVG(total_metadata_blocks) AS avg_total\n" + " FROM stl_commit_stats c,\n" + " stl_commit_internal_stats i\n" + " WHERE c.xid = i.xid\n" + " < ...even more sql >;\n" + "'2021-06-23T08:02:30Z UTC [ LOG: SELECT per_commit_info.day AS day, COUNT(*) AS commits,\n"; 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