sigactdemo.c

unix linux 编程实践源代码

/* sigactdemo.c
 *               purpose: shows use of sigaction()
 *               feature: blocks ^\ while handling ^C
 *                        does not reset ^C handler, so two kill
 */

#include	<stdio.h>
#include	<signal.h>
#define	INPUTLEN	100

main()
{
	struct sigaction newhandler;            /* new settings        */
	sigset_t         blocked;               /* set of blocked sigs */
	void		 inthandler();          /* the handler         */
	char		 x[INPUTLEN];

	/* load these two members first */
	newhandler.sa_handler = inthandler;      /* handler function    */
	newhandler.sa_flags = SA_RESETHAND | SA_RESTART;  /* options    */

	/* then build the list of blocked signals */
	sigemptyset(&blocked);                  /* clear all bits      */
	sigaddset(&blocked, SIGQUIT);		/* add SIGQUIT to list */

	newhandler.sa_mask = blocked;		/* store blockmask     */

	if ( sigaction(SIGINT, &newhandler, NULL) == -1 )
		perror("sigaction");
	else
		while( 1 ){
			fgets(x, INPUTLEN, stdin);
			printf("input: %s", x);
		}
}

void inthandler(int s)
{
	printf("Called with signal %d\n", s);
	sleep(s);
	printf("done handling signal %d\n", s);
}