Regular Expressions 101

Save & Manage Regex

  • Current Version: 1
  • Save & Share
  • Community Library

Flavor

  • PCRE2 (PHP)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java
  • .NET 7.0 (C#)
  • Rust
  • PCRE (Legacy)
  • Regex Flavor Guide

Function

  • Match
  • Substitution
  • List
  • Unit Tests
Sponsors
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 re regex = re.compile(r"([A-Z][a-z]{2} [A-Z][a-z]{2} \d{2} \d{2}:\d{2}:\d{2} CET \d{4})\n(/dev.*?) ==> (.*?)\n.*?\n(\d*) bytes .*? copied, (.*?) s, (.*?) (.*?s\n)(.*?)Exit status: (\d*)\n", flags=re.DOTALL | re.MULTILINE) test_str = ("Thu Feb 11 15:01:37 CET 2021\n" "/dev/mapper/vgdata-euramis_u000 ==> /ec/prod/server/euramis/u000\n" "1+0 records in\n" "1+0 records out\n" "512 bytes (512 B) copied, 0.00383015 s, 134 kB/s\n" " Command being timed: \"dd if=/dev/zero of=/ec/prod/server/euramis/u000/TstPerf/test_512_1 bs=512 count=1 oflag=dsync\"\n" " User time (seconds): 0.00\n" " System time (seconds): 0.00\n" " Percent of CPU this job got: 25%\n" " Elapsed (wall clock) time (h:mm:ss or m:ss): 0:00.00\n" " Average shared text size (kbytes): 0\n" " Average unshared data size (kbytes): 0\n" " Average stack size (kbytes): 0\n" " Average total size (kbytes): 0\n" " Maximum resident set size (kbytes): 812\n" " Average resident set size (kbytes): 0\n" " Major (requiring I/O) page faults: 0\n" " Minor (reclaiming a frame) page faults: 252\n" " Voluntary context switches: 4\n" " Involuntary context switches: 1\n" " Swaps: 0\n" " File system inputs: 0\n" " File system outputs: 8\n" " Socket messages sent: 0\n" " Socket messages received: 0\n" " Signals delivered: 0\n" " Page size (bytes): 4096\n" " Exit status: 0\n" "Thu Feb 11 16:02:17 CET 2021\n" "/dev/mapper/vgdata-euramis_u000 ==> /ec/prod/server/euramis/u000\n" "1+0 records in\n" "1+0 records out\n" "512 bytes (512 B) copied, 0.00275458 s, 186 kB/s\n" " Command being timed: \"dd if=/dev/zero of=/ec/prod/server/euramis/u000/TstPerf/test_512_1 bs=512 count=1 oflag=dsync\"\n" " User time (seconds): 0.00\n" " System time (seconds): 0.00\n" " Percent of CPU this job got: 33%\n" " Elapsed (wall clock) time (h:mm:ss or m:ss): 0:00.00\n" " Average shared text size (kbytes): 0\n" " Average unshared data size (kbytes): 0\n" " Average stack size (kbytes): 0\n" " Average total size (kbytes): 0\n" " Maximum resident set size (kbytes): 816\n" " Average resident set size (kbytes): 0\n" " Major (requiring I/O) page faults: 0\n" " Minor (reclaiming a frame) page faults: 253\n" " Voluntary context switches: 4\n" " Involuntary context switches: 1\n" " Swaps: 0\n" " File system inputs: 0\n" " File system outputs: 8\n" " Socket messages sent: 0\n" " Socket messages received: 0\n" " Signals delivered: 0\n" " Page size (bytes): 4096\n" " Exit status: 0\n" "Thu Feb 11 17:02:26 CET 2021\n" "/dev/mapper/vgdata-euramis_u000 ==> /ec/prod/server/euramis/u000\n" "1+0 records in\n" "1+0 records out\n" "512 bytes (512 B) copied, 0.00323523 s, 158 kB/s\n" " Command being timed: \"dd if=/dev/zero of=/ec/prod/server/euramis/u000/TstPerf/test_512_1 bs=512 count=1 oflag=dsync\"\n" " User time (seconds): 0.00\n" " System time (seconds): 0.00\n" " Percent of CPU this job got: 25%\n" " Elapsed (wall clock) time (h:mm:ss or m:ss): 0:00.00\n" " Average shared text size (kbytes): 0\n" " Average unshared data size (kbytes): 0\n" " Average stack size (kbytes): 0\n" " Average total size (kbytes): 0\n" " Maximum resident set size (kbytes): 820\n" " Average resident set size (kbytes): 0\n" " Major (requiring I/O) page faults: 0\n" " Minor (reclaiming a frame) page faults: 252\n" " Voluntary context switches: 4\n" " Involuntary context switches: 1\n" " Swaps: 0\n" " File system inputs: 0\n" " File system outputs: 8\n" " Socket messages sent: 0\n" " Socket messages received: 0\n" " Signals delivered: 0\n" " Page size (bytes): 4096\n" " Exit status: 0\n") matches = regex.finditer(test_str) for match_num, match in enumerate(matches, start=1): print(f"Match {match_num} was found at {match.start()}-{match.end()}: {match.group()}") for group_num, group in enumerate(match.groups(), start=1): print(f"Group {group_num} found at {match.start(group_num)}-{match.end(group_num)}: {group}")

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 Python, please visit: https://docs.python.org/3/library/re.html