我试图了解管道是如何在C中工作的。 我的父进程生成从1到10的整数并将它们写入管道。我的子进程必须读取管道并将值打印到屏幕上。父亲等待孩子终止并退出。很简单,对吧?这里是我的代码:从管道跳过读取整数C中的值跳过
#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <sys/types.h>
#include <errno.h>
#include <string.h>
#define WRITE 1
#define READ 0
#define N 10
int main(void)
{
pid_t pid;
int B0[2];
int num, status, i;
pipe(B0);
pid = fork();
if (pid > 0){
/*P0*/
close(B0[READ]);
for (i=1; i<=N; i++){
num = i;
write(B0[WRITE],&num,sizeof(num));
printf("P0: written %d\n", num);
}
close(B0[WRITE]);
wait(&status);
exit(EXIT_SUCCESS);
}
else if (pid == 0){
/*P1*/
close(B0[WRITE]);
do{
if (read(B0[READ],&num,sizeof(num)) != -1)
printf("P1: read %d from pipe B0\n", num);
else
printf("read: %s\n", strerror(errno));
} while(read(B0[READ],&num,sizeof(num)) != 0);
exit(EXIT_SUCCESS);
}
}
我不明白,为什么作为输出我收到以下:
P0: written 1
P0: written 2
P0: written 3
P0: written 4
P0: written 5
P0: written 6
P0: written 7
P0: written 8
P0: written 9
P0: written 10
P1: read 1 from pipe B0
P1: read 3 from pipe B0
P1: read 5 from pipe B0
P1: read 7 from pipe B0
P1: read 9 from pipe B0
P1: read 10 from pipe B0
不管我在管写整数序列中,我阅读()跳过每第二个值。我试着睡觉(1),而将值写入管道,但结果是一样的。我错过了一些东西,但我没有得到什么。 发生了什么?