fifo1.c

linux下进程间通信方式之一的fifo读写源程序。

#include <unistd.h> //修改
#include <string.h>    //修改
#include <stdio.h>    //修改
#include <sys/types.h>
#include <sys/stat.h>
#include <errno.h>
#include <fcntl.h>
#define FIFO_SERVER "/tmp/fifo"
//extern  FIFO_SERVER;
int main(int argc, char ** argv)
{
	int fd,fd1,real_wnum;
	int s=67;
	char value[256];
	sprintf(value,"%d",s);
	mkfifo(FIFO_SERVER,O_CREAT|O_EXCL);
	fd = open(FIFO_SERVER,O_WRONLY,0);
	
	if ( -1 == fd )
	{
		perror("open error");

	}
	
	
      fd1 = fork();
	switch( fd1)
        {
		case 0:
		{
			char *arg= "//root//./fifo2";
			
			execv(*arg,NULL);
			printf("start fifo2\n");
					
			break;
		}
		case -1:
			printf("error\n");
			break;
		default:
			
			break;
	}
	real_wnum = write(fd,value,sizeof(value));
			if(real_wnum==-1)
    			{
        			if(errno==EAGAIN)
            		printf("write to fifo error; try later\n");
    			}
    			else 
      			printf("real write num is %d\n",real_wnum);
    				real_wnum=write(fd,value,sizeof(value));
    
    				if(real_wnum==-1)
        				if(errno==EAGAIN)
            				printf("try later\n");
			return 0;	

	return 0;
	

}