gcc/fortran/doc/gfortran/intrinsic-procedures/verify.rst

   1 ..
   2   Copyright 1988-2022 Free Software Foundation, Inc.
   3   This is part of the GCC manual.
   4   For copying conditions, see the copyright.rst file.
   5
   6 .. index:: VERIFY, string, find missing set
   7
   8 .. _verify:
   9
  10 VERIFY --- Scan a string for characters not a given set
  11 *******************************************************
  12
  13 .. function:: VERIFY(STRING, SET, BACK , KIND)
  14
  15   Verifies that all the characters in :samp:`{STRING}` belong to the set of
  16   characters in :samp:`{SET}`.
  17
  18   :param STRING:
  19     Shall be of type ``CHARACTER``.
  20
  21   :param SET:
  22     Shall be of type ``CHARACTER``.
  23
  24   :param BACK:
  25     (Optional) shall be of type ``LOGICAL``.
  26
  27   :param KIND:
  28     (Optional) An ``INTEGER`` initialization
  29     expression indicating the kind parameter of the result.
  30
  31   :return:
  32     The return value is of type ``INTEGER`` and of kind :samp:`{KIND}`. If
  33     :samp:`{KIND}` is absent, the return value is of default integer kind.
  34
  35   Standard:
  36     Fortran 90 and later, with :samp:`{KIND}` argument Fortran 2003 and later
  37
  38   Class:
  39     Elemental function
  40
  41   Syntax:
  42     .. code-block:: fortran
  43
  44       RESULT = VERIFY(STRING, SET[, BACK [, KIND]])
  45
  46   Example:
  47     .. code-block:: fortran
  48
  49       PROGRAM test_verify
  50         WRITE(*,*) VERIFY("FORTRAN", "AO")           ! 1, found 'F'
  51         WRITE(*,*) VERIFY("FORTRAN", "FOO")          ! 3, found 'R'
  52         WRITE(*,*) VERIFY("FORTRAN", "C++")          ! 1, found 'F'
  53         WRITE(*,*) VERIFY("FORTRAN", "C++", .TRUE.)  ! 7, found 'N'
  54         WRITE(*,*) VERIFY("FORTRAN", "FORTRAN")      ! 0' found none
  55       END PROGRAM
  56
  57   See also:
  58     :ref:`SCAN`,
  59     :ref:`index-intrinsic`