select.c

这是linux下的基础C编程代码。都是已经调试成功的

b b#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <time.h>


int main()
{
	int fds[2];
	char buf[7];

	int i,rc,maxfd;
	fd_set inset1,inset2;

	struct timeval tv;

	if(fds[0]=open("hello1",O_RDWR|O_CREAT,0666)<0)
	{
		perror("open hello1 error!\n");
	}

	if(fds[1]=open("hello2",O_RDWR|O_CREAT,0666)<0)
	{
		perror("open hello2 error!\n");
	}

	if((rc=write(fds[0],"hello!\n",7)))
	{
		printf("rc=%d\n",rc);
	}

	lseek(fds[0],0,SEEK_SET);

    maxfd=fds[0]>fds[1]?fds[0]:fds[1];

	FD_ZERO(&inset1);
	FD_SET(fds[0],&inset1);


	FD_ZERO(&inset2);
	FD_SET(fds[1],&inset2);

	tv.tv_sec=2;
	tv.tv_usec=0;

	while(FD_ISSET(fds[0],&inset1)||FD_ISSET(fds[1],&inset2))
	{
		
	    if(select(maxfd+1,&inset1,&inset2,NULL,&tv)<0)
		{
			printf("select error\n");
		}
        else
		{
			if(FD_ISSET(fds[0],&inset1))
			{
				rc=read(fds[0],buf,7);
				if(rc>0)
				{
				  buf[rc]='\0';
                  printf("read:%s\n",buf);
				  printf("hello1,i got it!\n");
				}
				else
				{
					printf("error\n");
				}
				
			}

			if(FD_ISSET(fds[1],&inset2))
			{
				
				rc=write(fds[1],buf,7);
				if(rc>0)
				{
				   buf[rc]='\0';
                  printf("read:%s\n",buf);
				  printf("hello2,i got it!\n");
				}
				else
				{
					printf("error\n");
				}
				sleep(5);
			}
            
		}		
	}
}