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

using System; using System.Text.RegularExpressions; public class Example { public static void Main() { string pattern = @"(?m)^.*(?:(?:201[8-9]|2\d[2-9]\d|[3-9]\d{3})-\d{2}-\d{2}|2017-(?:12-\d{2}|11-(?:0[6-9]|[12]\d|3[01])))$"; string input = @"drwxrwxr-x - testetl hdp_test 0 2018-02-02 05:10 /raw/ADS/ClicksData/click/datetm=2017-10-15 drwxrwxr-x - testetl hdp_test 0 2018-02-01 09:35 /raw/ADS/ClicksData/click/datetm=2017-10-16 drwxrwxr-x - testetl hdp_test 0 2018-01-31 21:54 /raw/ADS/ClicksData/click/datetm=2017-10-17 drwxrwxr-x - testetl hdp_test 0 2018-01-31 23:59 /raw/ADS/ClicksData/click/datetm=2017-10-18 drwxrwxr-x - testetl hdp_test 0 2018-01-31 21:49 /raw/ADS/ClicksData/click/datetm=2017-10-19 drwxrwxr-x - testetl hdp_test 0 2018-02-01 09:32 /raw/ADS/ClicksData/click/datetm=2017-10-20 drwxrwxr-x - testetl hdp_test 0 2018-02-02 11:51 /raw/ADS/ClicksData/click/datetm=2017-10-21 drwxrwxr-x - testetl hdp_test 0 2018-02-01 09:08 /raw/ADS/ClicksData/click/datetm=2017-10-22 drwxrwxr-x - testetl hdp_test 0 2018-01-31 22:42 /raw/ADS/ClicksData/click/datetm=2017-10-23 drwxrwxr-x - testetl hdp_test 0 2018-02-01 09:58 /raw/ADS/ClicksData/click/datetm=2017-10-24 drwxrwxr-x - testetl hdp_test 0 2018-02-02 05:10 /raw/ADS/ClicksData/click/datetm=2017-10-25 drwxrwxr-x - testetl hdp_test 0 2018-02-01 09:46 /raw/ADS/ClicksData/click/datetm=2017-10-26 drwxrwxr-x - testetl hdp_test 0 2018-02-01 09:04 /raw/ADS/ClicksData/click/datetm=2017-10-27 drwxrwxr-x - testetl hdp_test 0 2018-02-01 09:46 /raw/ADS/ClicksData/click/datetm=2017-10-28 drwxrwxr-x - testetl hdp_test 0 2018-02-02 00:21 /raw/ADS/ClicksData/click/datetm=2017-10-29 drwxrwxr-x - testetl hdp_test 0 2018-02-02 05:09 /raw/ADS/ClicksData/click/datetm=2017-10-30 drwxrwxr-x - testetl hdp_test 0 2018-02-02 05:13 /raw/ADS/ClicksData/click/datetm=2017-10-31 drwxrwxr-x - testetl hdp_test 0 2018-02-01 14:34 /raw/ADS/ClicksData/click/datetm=2017-11-01 drwxrwxr-x - testetl hdp_test 0 2018-02-02 09:20 /raw/ADS/ClicksData/click/datetm=2017-11-02 drwxrwxr-x - testetl hdp_test 0 2018-02-01 14:35 /raw/ADS/ClicksData/click/datetm=2017-11-03 drwxrwxr-x - testetl hdp_test 0 2018-02-01 09:42 /raw/ADS/ClicksData/click/datetm=2017-11-04 drwxrwxr-x - testetl hdp_test 0 2018-02-02 09:18 /raw/ADS/ClicksData/click/datetm=2017-11-05 drwxrwxr-x - testetl hdp_test 0 2018-02-01 09:11 /raw/ADS/ClicksData/click/datetm=2017-11-06 drwxrwxr-x - testetl hdp_test 0 2018-01-31 17:56 /raw/ADS/ClicksData/click/datetm=2017-11-07 drwxrwxr-x - testetl hdp_test 0 2018-01-31 21:36 /raw/ADS/ClicksData/click/datetm=2017-11-08 drwxrwxr-x - testetl hdp_test 0 2018-01-31 16:43 /raw/ADS/ClicksData/click/datetm=2017-11-09 drwxrwxr-x - testetl hdp_test 0 2018-01-31 21:59 /raw/ADS/ClicksData/click/datetm=2017-11-10 drwxrwxr-x - testetl hdp_test 0 2018-02-01 09:23 /raw/ADS/ClicksData/click/datetm=2017-11-11 "; RegexOptions options = RegexOptions.Multiline; foreach (Match m in Regex.Matches(input, pattern, options)) { Console.WriteLine("'{0}' found at index {1}.", m.Value, m.Index); } } }

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 C#, please visit: https://msdn.microsoft.com/en-us/library/system.text.regularexpressions.regex(v=vs.110).aspx