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

$re = '/^\d+-\d+-\d+\s+\d+:\d+:\d+\s+\d+\.\d+\.\d+\.\d+\s+\w+\s\/[^ ]+\s+[^ ]+\s+\d+\s+(?<cs_username>[^ ]+)\s+/m'; $str = '2020-05-15 04:58:34 10.140.14.228 POST /NotAvailable.aspx - 80 Gerardot 10.140.15.235 Mozilla/5.0+(Linux;+Android+9;+SM-G960U)+AppleWebKit/537.36+(KHTML,+like+Gecko)+Chrome/74.0.3729.136+Mobile+Safari/537.36 302 0 0 15 172.69.69.111 2020-05-15 04:57:19 10.140.14.228 POST /Account/Login.aspx - 80 Kaitlyn1230 10.140.15.235 Mozilla/5.0+(iPhone;+CPU+iPhone+OS+13_4+like+Mac+OS+X)+AppleWebKit/605.1.15+(KHTML,+like+Gecko)+GSA/107.0.310639584+Mobile/15E148+Safari/604.1 200 0 0 46 162.158.75.109 2020-05-15 04:54:24 10.140.14.228 POST /PaymentInfo.aspx - 80 Emulbah 10.140.15.235 Mozilla/5.0+(Windows+NT+6.1;+Win64;+x64)+AppleWebKit/537.36+(KHTML,+like+Gecko)+Chrome/81.0.4044.138+Safari/537.36 302 0 0 46 172.68.150.39'; preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0); // Print the entire match result var_dump($matches);

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 PHP, please visit: http://php.net/manual/en/ref.pcre.php