fifo_read.c

linux下有命管道和无名管道的使用。以及管道读写规则

#include <sys/stat.h>
#include <sys/types.h>
#include <stdio.h>
#include <errno.h>
#include <fcntl.h>
#define FIFO_NAME  "/tmp/cn0803_fifo"

int main(int argc,char *argv[])
{
	int fd;
	char buffer[128]={'\0'};
	int read_count=0;
	if (access(FIFO_NAME,F_OK)==-1)
	{
		if(mkfifo(FIFO_NAME,O_CREAT|0666)==-1)
		{
			perror("mkfifo:");
			return -1;
		}
	}
	printf("ready open fifo..\n");
	fd=open(FIFO_NAME,O_RDONLY);
	printf("read data\n");
	fcntl(fd,F_SETFL,O_NONBLOCK);
	//while( (read_count=read(fd,buffer,sizeof(buffer)))>0)
	//{
		//printf("%s\n",buffer);
	//}
	read_count=read(fd,buffer,sizeof(buffer));
	printf("read_count=%d",read_count);
	if (errno==EAGAIN)
		printf("EAGAIN\n");
	printf("vvvvvvv\n");
	return 0;
}