8.248 SIGNAL — Signal handling subroutine (or function)

Description:

SIGNAL(NUMBER, HANDLER [, STATUS]) causes external subroutine HANDLER to be executed with a single integer argument passed by value when signal NUMBER occurs. If HANDLER is an integer, it can be used to turn off handling of signal NUMBER or revert to its default action. See signal(2).

If SIGNAL is called as a subroutine and the STATUS argument is supplied, it is set to the value returned by signal(2).

Standard:

GNU extension

Class:

Subroutine, function

Syntax:

CALL SIGNAL(NUMBER, HANDLER [, STATUS])

STATUS = SIGNAL(NUMBER, HANDLER)

Arguments:

`NUMBER`	Shall be a scalar integer, with `INTENT(IN)`
`HANDLER`	Signal handler (`INTEGER FUNCTION` or `SUBROUTINE`) or dummy/global `INTEGER` scalar. `INTEGER`. It is `INTENT(IN)`.
`STATUS`	(Optional) `STATUS` shall be a scalar integer. It has `INTENT(OUT)`.

Return value:

The SIGNAL function returns the value returned by signal(2).

Example:

module m_handler
contains
  ! POSIX.1-2017:  void (*func)(int)
  subroutine handler_print(signum) bind(C)
    use iso_c_binding, only: c_int
    integer(c_int), value :: signum
    print *, 'handler_print invoked with signum =', signum
  end subroutine
end module
program test_signal
  use m_handler
  intrinsic :: signal, sleep
  call signal (12, handler_print)  ! 12 = SIGUSR2 (on some systems)
  call signal (10, 1)  ! 10 = SIGUSR1 and 1 = SIG_IGN (on some systems)

  call sleep (30)
end program test_signal

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Licensed under the GNU Free Documentation License, Version 1.3.
https://gcc.gnu.org/onlinedocs/gcc-14.2.0/gfortran/SIGNAL.html