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

/
/
gmis

Test String

Code Generator

Language

Generated Code

package main import ( "regexp" "fmt" ) func main() { var re = regexp.MustCompile(`(?mis)(?P<headers>.*)[\r\n][\r\n](?P<content>.*)`) var str = `------WebKitFormBoundary3JCHTJWwvnOcvnSv Content-Disposition: form-data; name="_format" json ------WebKitFormBoundary3JCHTJWwvnOcvnSv Content-Disposition: form-data; name="rid" 1 ------WebKitFormBoundary3JCHTJWwvnOcvnSv Content-Disposition: form-data; name="avatar"; filename="carlingford.jpg" Content-Type: image/jpeg ���p�� ��T!1"AQa2q�#B�� R�$3b�C���%r�4S�&�5c Ds��'ET�d6U��� ��L!1AQaq"��2����#��BR�b$3r����C%4S��s�&5DTc���?�g������F΅%v9��Ge�9�С@#B�'�y�4!p|hPW%<�8�:n��9�hI�B;�Ж�:R{�8Ћ(�m�:m�*����0��vƄ#��?'B���BQ����BGo} ;#�a#�΄U��W�x?�E��H��:��#Ռ�t�L�6C�u ��#�R����22����n�c���B�@3ƅ"��ZRN�dv΄�����Д��pB��'B]�rҥ�����Q���)P�� �R�����R9Y�I&��� =���X?�bI�u��ĮQ���!C�'dn�}��-n�s�j8 �c$����Q����$�q��� �@�J9$ryԁj�pN�9���B8+*��v�Sih�J}[�W��ґ���R�r�?��h�I�J!�P�?J��+��T���+��Q�)�m od` for i, match := range re.FindAllString(str, -1) { fmt.Println(match, "found at index", 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 Golang, please visit: https://golang.org/pkg/regexp/