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"
"
gms

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<error_msg>.*?)(?:exit\\s+code:\\s+)(?P<exit_code>\\d+).(?:Stdout:)(?P<stdout>.*?)(?:Stderr:)(?P<stderr>.*?)(?:CUSTOM_EOF)"; final String string = "process \"pipenv run pylint --rcfile .linting-configs/pylintrc ci/dagger/automation.py ci/dagger/async_interface.py ci/dagger/models/linting.py ci/dagger/models/config.py ci/dagger/linting.py ci/dagger/helper.py\" did not complete successfully: exit code: 28\n" + "Stdout:\n" + "o snake_case naming style (invalid-name)\n" + "************* Module models.linting\n" + "ci/dagger/models/linting.py:9:0: C0115: Missing class docstring (missing-class-docstring)\n" + "ci/dagger/models/linting.py:15:22: C0103: Argument name \"v\" doesn't conform to snake_case naming style (invalid-name)\n" + "ci/dagger/models/linting.py:33:0: C0115: Missing class docstring (missing-class-docstring)\n" + "ci/dagger/models/linting.py:44:4: C0115: Missing class docstring (missing-class-docstring)\n" + "ci/dagger/models/linting.py:44:4: R0903: Too few public methods (0/2) (too-few-public-methods)\n" + "ci/dagger/models/linting.py:33:0: R0903: Too few public methods (1/2) (too-few-public-methods)\n" + "ci/dagger/models/linting.py:48:0: C0115: Missing class docstring (missing-class-docstring)\n" + "************* Module models.config\n" + "ci/dagger/models/config.py:6:0: C0115: Missing class docstring (missing-class-docstring)\n" + "ci/dagger/models/config.py:6:0: R0903: Too few public methods (0/2) (too-few-public-methods)\n" + "************* Module linting\n" + "ci/dagger/linting.py:37:4: W0613: Unused argument 'client' (unused-argument)\n" + "ci/dagger/linting.py:179:4: W0613: Unused argument 'client' (unused-argument)\n" + "ci/dagger/linting.py:240:4: W0613: Unused argument 'client' (unused-argument)\n" + "ci/dagger/linting.py:301:4: W0613: Unused argument 'client' (unused-argument)\n" + "ci/dagger/linting.py:5:0: W0611: Unused import click (unused-import)\n" + "ci/dagger/linting.py:7:0: W0611: Unused QueryError imported from dagger.exceptions (unused-import)\n" + "************* Module helper\n" + "ci/dagger/helper.py:51:0: C0116: Missing function or method docstring (missing-function-docstring)\n" + "ci/dagger/helper.py:88:0: C0115: Missing class docstring (missing-class-docstring)\n" + "ci/dagger/helper.py:122:0: C0116: Missing function or method docstring (missing-function-docstring)\n" + "ci/dagger/helper.py:133:19: W0212: Access to a protected member _raw_input of a client class (protected-access)\n" + "ci/dagger/helper.py:1:0: W0611: Unused getenv imported from os (unused-import)\n\n" + "-----------------------------------\n" + "Your code has been rated at 8.45/10\n" + "Stderr:\n" + "CUSTOM_EOF"; final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE | Pattern.DOTALL); 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