fifo_read.c

关于进程间通信的代码集锦

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

int main(int argc,char** argv)
{
	int fd;
	char r_buf[4096*2];
	int r_size;
	int ret_size;
	r_size=atoi(argv[1]);
	printf("required real read bytes %d\n",r_size);
	memset(r_buf,0,sizeof(r_buf));
	if((mkfifo(FIFO_SERVER,O_CREAT|O_EXCL)<0)&&(errno!=EEXIST))
	{
		printf("cannot create fifoserver");
	}
	printf("Preparing for reading bytes...\n");

	fd=open(FIFO_SERVER,O_RDONLY,0);
	if(fd==-1)
	{
		printf("open %s for read error\n",FIFO_SERVER);
		exit(0);
	}
	while(1)
	{
		memset(r_buf,0,sizeof(r_buf));
		ret_size=read(fd,r_buf,r_size);
		if(ret_size==-1)
		{	
			if(errno==EAGAIN)
			{
				printf("no data avilable.\n");
			}
		}
		
		printf("real read bytes %d\n",ret_size);
		sleep(1);
	}
	pause();
	unlink(FIFO_SERVER);
	return 0;
}