signal - C signal.h

Type

function

From

<signal.h>
<csignal>

Description

Set function to handle signal

Prototype

void (*signal(int sig, void (*func)(int)))(int);

Parameters

Parameter	Description
sig	The signal value to which a handling function is set.
func	A pointer to a function.

The following macro constant expressions identify standard signal values:

macro	stands for	signal
SIGABRT	Signal Abort	Abnormal termination.
SIGFPE	Signal Floating-Point Exception	Erroneous arithmetic operation.
SIGILL	Signal Illegal Instruction	due to a corruption in the code or to an attempt to execute data.
SIGINT	Signal Interrupt	Generally generated by the application user.
SIGSEGV	Signal Segmentation Violation	Invalid access to storage when trying to access outside the memory it is allocated for it.
SIGTERM	Signal Terminate	Termination request sent to program.

func may either be a function defined by the programmer or one of the following predefined functions:

Value	Description
SIG_DFL	Default handling: The signal is handled by the default action for that particular signal.
SIG_IGN	Ignore Signal: The signal is ignored.

If a function, it should follow the following prototype:

void handler_function (int parameter);

Return value

The return type is the same as the type of parameter func.

Demo Code


#include <stdio.h>
#include <signal.h>

sig_atomic_t signaled = 0;/*  ww w  .  j a  v  a  2s.c  om*/

void my_handler (int param){
  signaled = 1;
}

int main (){
  void (*prev_handler)(int);

  prev_handler = signal (SIGINT, my_handler);

  raise(SIGINT);

  printf ("signaled is %d.\n",signaled);

  return 0;
}