fifo_open_test.c

这个资料非常不错

/*******************
 * fifo_open_test.c*
 *******************/
#include <sys/types.h>
#include <sys/stat.h>
#include <errno.h>
#include <fcntl.h>
#define FIFO_SERVER "/tmp/fifoserver"

int handle_client(char*);
main(int argc,char** argv)
{
	int r_rd;
	int w_fd;
	pid_t pid;

	if((mkfifo(FIFO_SERVER,O_CREAT|O_EXCL)<0)&&(errno!=EEXIST))
		printf("cannot create fifoserver\n");
	handle_client(FIFO_SERVER);
	
}

int handle_client(char* arg)
{
int ret;
ret=w_open(arg);
switch(ret)
{
	case 0:
	{	
	printf("open %s error\n",arg);
	printf("no process has the fifo open for reading\n");
	return -1;
	}
	case -1:
	{
		printf("something wrong with open the fifo except for ENXIO");
		return -1;
	}
	case 1:
	{
		printf("open server ok\n");
		return 1;
	}
	default:
	{
		printf("w_no_r return ????\n");
		return 0;
	}
}		
unlink(FIFO_SERVER);
}

int w_open(char*arg)
//0  open error for no reading
//-1 open error for other reasons
//1  open ok
{
	if(open(arg,O_WRONLY|O_NONBLOCK,0)==-1)
	{	if(errno==ENXIO)
		{
			return 0;
		}
		else
		return -1;
	}
	return 1;
	
}