请教LINUX C问题

prayerwy2046

main( )
{
int fd[2];
char outpipe[100],inpipe[100];
pipe(fd); /*创建一个管道*/
while ((pid1=fork( ))= =-1);
if(pid1= =0)
{
lockf(fd[1],1,0);
sprintf(outpipe,"child 1 process is sending message!");
/*把串放入数组outpipe中*/
write(fd[1],outpipe,50); /*向管道写长为50字节的串*/
sleep(5); /*自我阻塞5秒*/
lockf(fd[1],0,0);
exit(0);
}
else
{
while((pid2=fork( ))= =-1);
if(pid2= =0)
{ lockf(fd[1],1,0); /*互斥*/
sprintf(outpipe,"child 2 process is sending message!");
write(fd[1],outpipe,50);
sleep(5);
lockf(fd[1],0,0);
exit(0);
}
else
{ wait(0); /*同步*/
read(fd[0],inpipe,50); /*从管道中读长为50字节的串*/
printf("%s\n",inpipe);
wait(0);
read(fd[0],inpipe,50);
printf("%s\n",inpipe);
exit(0);
}
}
}

这样一个程序，为什么执行结果是
child 1 process is sending message!
child 2 process is sending message!
而不执行printf("%s\n",inpipe);呢?

prayerwy2046

我明白了，不用大家解释了

prayerwy2046

还想问一下  write(fd[1],outpipe,50);   向fd[1]里写数据,为什么是从read(fd[0],inpipe,50); fd[0]里读呢?

asert

Post by prayerwy2046
还想问一下  write(fd[1],outpipe,50);   向fd[1]里写数据,为什么是从read(fd[0],inpipe,50); fd[0]里读呢?

pipe(fd)把fd[0]和fd[1]连起来了阿，像一个管道一样.fd[0]是用来读的，fd[1]是用来写的.