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

/
/
g

Test String

Code Generator

Language

Generated Code

$re = '/^(-----BEGIN (RSA )?(PUBLIC|PRIVATE) KEY-----\n)(.|\n)+(-----END (RSA )?(PUBLIC|PRIVATE) KEY-----)$/'; $str = '-----BEGIN RSA PRIVATE KEY----- MIICWwIBAAKBgQCG4Y5mYMYmwhyuayJseb1c7Gvh1fbhFLgUuqrjtx1fTL82p45l Bb3nIz8Cn3DHLeylKTvVtF67bTf1/cWKtPPvskrWLKvR8WrN4FEyOI7S0kcZZOqX cZCGHk4MMzoZS5BnaxZsO3WRNk9K3gM0zJtnD+2Gy/ZdVuzaK9kevVJX2QIDAQAB AoGAPa7bI4CwPbtZyH4gMQF/kwZf09i43XhPMtOnIRp16UY8z+7SlOqKTTD2OOnX do9PAL0ZqwKgrBAnnmyesW9NeqoOBBX84p9Ydiqc11oj7sjKawETC+eXB83eJB4T sFWXzLdUq/T5uLEl0Nc+ekQPunazUWLx5Tgt/AqoJoLgmC0CQQDxBPoX+BEHfkLH f/yThnZ3GJaDnh6gQfBcjyJhuxgHxa/obPCot0kVgm6jzuVNy7ykwc+2dw+4T0/j QBPRzm4bAkEAj0O9fB+9W8Ytvsnussg9XHGxTtXsY2/iocrJSkRuhsPsczctO5Zw JYcnBorFzxFqFGg7SdillrrRoEIuicXhGwJAGnIYWv7uJ2tUOn2xoiJT51d8VG7K H318uTs/Y4fa6Cdp2M/zTB/oVgLczv6JrJKZXV6iwvunburM8jt6sT+8VwJAGLcM 917aYfy8Y4+emEUnIM2UUw9gqn7g0ByVwTQxBRrDrdS0/vSjADZiqyRBn8lXTZH1 uHWhi3FLPKRuNuJmRQJAL3WcSNzsLIJqX3lOkH5dFanLUxGpdS4w//0uz4T6TzoJ ZvIFblnqe/RGHLWJfHra3q9jtizDH0lyBtgsZ5msmg== -----END RSA PRIVATE KEY-----'; preg_match_all($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