pipe_writeato.c

关于进程间通信的代码集锦

#include <unistd.h>
#include <sys/types.h>
#include <errno.h>

int main()
{
	int pipe_fd[2];
	pid_t pid;
	char r_buf[4096];
	char w_buf[4096*2];	
	int writenum;
	int rnum;
	
	memset(r_buf,0,sizeof(r_buf));
	if(pipe(pipe_fd)<0)
	{
		printf("pipe create error\n");
		return -1;
	}

	if((pid=fork())==0)
	{
		printf("In child process\n");		
		close(pipe_fd[1]);
		while(1)
		{	
			sleep(1);
			rnum=read(pipe_fd[0],r_buf,1000);
			printf("child:readnum is %d\n",rnum);			
		}
		close(pipe_fd[0]);		
		exit(0);		
	}
	else if(pid>0)
	{		
		printf("In parent process\n");
		close(pipe_fd[0]);
		memset(r_buf,0,sizeof(r_buf));
		if((writenum=write(pipe_fd[1],w_buf,5000))==-1)
		{
			printf("write to pipe error\n");
		}
		else
		{
			printf("the bytes write to pipe is %d \n",writenum);
		}
		writenum=write(pipe_fd[1],w_buf,5000);
		close(pipe_fd[1]);
	}
	
	return 0;
}