sig1.c

这个资料非常不错

/*********
 *sig1.c *
 *********/
#include <stdio.h> 
#include <stdlib.h>
#include <signal.h>
#include <sys/types.h> 

int main(int argc,char **argv)
{
 double y;
 sigset_t intmask;
 int i,repeat_factor;

 if(argc!=2)
  {
  fprintf(stderr,"Usage:%s repeat_factor\n\a",argv[0]);
  exit(1);
  }

 if((repeat_factor=atoi(argv[1]))<1)repeat_factor=10;
   sigemptyset(&intmask);   
   sigaddset(&intmask,SIGINT);
 while(1)
  {

  sigprocmask(SIG_BLOCK,&intmask,NULL);
  fprintf(stderr,"SIGINT signal blocked\n");
  for(i=0;i<repeat_factor;i++)
  fprintf(stderr,"Blocked calculation is finished\n");

  sigprocmask(SIG_UNBLOCK,&intmask,NULL);
  fprintf(stderr,"SIGINT signal unblocked\n");
  for(i=0;i<repeat_factor;i++)
        fprintf(stderr,"Unblocked calculation is finished\n");
  }
  exit(0);
}