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

/
/
ig

Test String

Code Generator

Generated Code

$re = '/(::\s*\b(function)\b)|\b(function)\b/i'; $str = 'type def integer, dimension(:), pointer :: ptr end type def interface set_scalar_field_from_python module procedure set_scalar_field_from_python_sp subroutine set_scalar_field_from_python(function, function_len, dim, & nodes, x, y, z, t, result, stat) use iso_c_binding, only: c_double, c_int, c_char implicit none integer(c_int), intent(in), value :: function_len character(kind=c_char, len=function_len) :: function integer(c_int), intent(in), value :: dim, nodes real(c_double), dimension(nodes), intent(in) :: x, y, z real(c_double), intent(in), value :: t real(c_double), dimension(nodes), intent(out) :: result integer(c_int), intent(out) :: stat end subroutine set_scalar_field_from_python ! all these should be in meta.parameter.fortran integer function fun_with_func_space( function ) integer, intent(inout) :: function end function fun_with_func_space subroutine sub_with_func_space( function ) character(kind=1, len=function_len), intent(inout) :: function end subroutine sub_with_func_space character(kind=1, len=function_len) function fun_with_sub_space( subroutine ) character(kind=1, len=function_len), intent(inout) :: subroutine end function fun_with_sub_space subroutine sub_with_sub_space( subroutine ) character(kind=1, len=function_len), intent(inout) :: subroutine end subroutine sub_with_sub_space subroutine normal( arg , simple ) character(kind=1, len=function_len), intent(inout) :: arg integer, intent(inout) :: simple end subroutine normal logical(kind=4) function foo(var) result(val) integer, intent(inout) :: var end function foo ! keyword.other.function.fortran function name(arg) integer :: arg end function name character(len=10) function foo_char() result(val) integer :: function end function foo_char end interface set_scalar_field_from_python'; preg_match_all($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