Regular Expressions 101

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  • PCRE2 (PHP >=7.3)
  • PCRE (PHP <7.3)
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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

/
/
gsm

Test String

Code Generator

Language

Generated Code

package main import ( "regexp" "fmt" ) func main() { var re = regexp.MustCompile(`(?sm)^(?<atributo>(?<pai>(?:[^=.\n]+)\.?){1,6})=(?<valor>(?:[^=\n]+))$`) var str = `php.environment.ini.session-name = sisicmbio php.environment.ini.session-cookie_domain = icmbio.gov.br php.environment.ini.session-auto_start = false php.environment.ini.session-cookie_path = / php.environment.ini.session-cookie_lifetime = 10800 php.environment.ini.session-cookie_httponly = true php.environment.ini.session-use_only_cookie = true php.environment.ini.session-gc_maxlifetime = 10800 php.environment.ini.session-cache_expire = 180 ;; [php server mail] php.mail.sender = smtp php.mail.from = notifica@domain.gov.br ; conta default usada para enviar mensagens php.mail.replyTo = reposta@domain.gov.br ; conta usada para reply php.mail.wordWrap = 60 php.mail.priority = 3 ; 1: high, 3: normal, 5: low php.mail.encoding = 8bit ; 8bit, 7bit, binary, base64, quoted-printable php.mail.charset = utf-8 php.mail.contentType = text/html` 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/