作业1：有名管道，创建两个发送接收端，父进程写入管道1和管道2，子进程读取管道2和管道1.

右进程 

#include <myhead.h>
int main(int argc, const char *argv[])
{
	pid_t pid=fork();
	if(pid>0)//父进程，将数据发送至管道1
	{
		int fd1;
		int len;
		char buff[1024];
		fd1=open("./fifo_a",O_WRONLY);
		if(fd1==-1)
		{
			perror("打开管道1");
			return -1;
		}
		while(1)
		{
			len=read(0,buff,sizeof(buff));//从键盘读取数据
			buff[strlen(buff)-1] = '\0';
			write(fd1,buff,len);//将数据发送至管道1
			if(strcmp(buff,"quit")==0)
			{
				break;
			}
		}

		close(fd1);
	}
	else if(pid==0)
	{
		int fd2;
		int len1;
		char buff1[1024];

		fd2=open("./fifo_b",O_RDONLY);
		if(fd2==-1)
		{
			perror("打开管道2");
			return -1;
		}
		while(1)
		{

			len1=read(fd2,buff1,sizeof(buff1));//从管道2读取数据
			write(1,buff1,len1);
			if(strcmp(buff1,"quit")==0)
			{
				break;
			}
		}
		close(fd2);
	}
	else
	{
		perror("pid");
		return -1;
	}
	return 0;
}

左进程 

#include <myhead.h>
int main(int argc, const char *argv[])
{
	pid_t pid=fork();
	if(pid>0)//父进程，将数据发送至管道1
	{
		int fd1;
		int len;
		char buff[1024];
		fd1=open("./fifo_b",O_WRONLY);
		if(fd1==-1)
		{
			perror("打开管道1");
			return -1;
		}
		while(1)
		{
			len=read(0,buff,sizeof(buff));//从键盘读取数据
			buff[len-1] = '\0';
			write(fd1,buff,len);//将数据发送至管道1
			if(strcmp(buff,"quit")==0)
			{
				break;
			}
		}

		close(fd1);
	}
	else if(pid==0)
	{
		int fd2;
		int len1;
		char buff1[1024];

		fd2=open("./fifo_a",O_RDONLY);
		if(fd2==-1)
		{
			perror("打开管道2");
			return -1;
		}
		while(1)
		{

			len1=read(fd2,buff1,sizeof(buff1));//从管道2读取数据
			
			write(1,buff1,len1);
			if(strcmp(buff1,"quit")==0)
			{
				break;
			}
		}
		close(fd2);
	}
	else
	{
		perror("pid");
		return -1;
	}
	return 0;
}