sigrecv.c

linux父子进程间关系

#include <stdio.h>
#include <signal.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>

#define M 2

void sighdlr(int signum);

int main()
{   
    pid_t a;
    signal(SIGUSR1, sighdlr);
    signal(SIGUSR2, sighdlr);
    a=getpid();
    printf("My pid is %d.\n",a);
    while(1);
    return 0;
}

void sighdlr(int signum)
{
    int fd0,fd1;
    int success;	 
    char s[M];
    switch (signum) 
    {
       case SIGUSR1:
           printf("Recived SIGUSR1\n");
           exit(0);
       break;
       case SIGUSR2:
           printf("Recived SIGUSR2\n");
	   if ((fd0 = open("temp.txt", O_RDONLY)) < 0)
               {
  	            write(STDERR_FILENO, "open file Error!\n",sizeof("open file Error!\n"));
  	            exit(1);
               }
           mkfifo("test.txt",0777);
           if ((fd1 = open("test.txt", O_WRONLY)) < 0)
               {
                    write(STDERR_FILENO, "open fifo file Error!\n",sizeof("open file Error!\n"));
                    exit(1);
               }
           success=read(fd0,s,M);
           while(success>0)
           {
               write(fd1,s,strlen(s));
               success=read(fd0,s,M);
           }
           close(fd0);
           close(fd1);
       break;
       default:
           break;
    }
}