Question

我创建了两个子进程，它们之间有管道连接。

流程A中的代码：

char *buf;
size_t size;

buf = "some string";
size = strlen(buf);
printf("size in process A:%zu\n", size);
write(pfds[3][1], &size, sizeof (size_t));
write(pfds[3][1], buf, sizeof (buf));


buf="other string";
size = strlen(buf);
printf("size in process A:%zu\n", size);
write(pfds[3][1], &size, sizeof (size_t));
write(pfds[3][1], buf, sizeof (buf));

流程B中的代码：

size_t size;
/*read in size from Process A*/
read(pfds[3][0], &size, sizeof (size_t));
printf("READ size in process B: %zu\n", size);

/*allocate memory space for the line*/
char *buf = malloc(size);

/*read in line from process A*/
read(pfds[3][0], buf, size);
printf("READ buf in process B: %s.\n", buf);

/*read in size from readProcess*/
read(pfds[3][0], &size, sizeof (size_t));
printf("READ size in process B:%zu\n", size);

/*free the allocated memory*/
free(buf);

输出如下：

size in process A:11
size in process A:12
READ size in process B: 11
READ buf in process B: some
                            .
READ size in process B:101

我想使用大小来控制while循环来连续发送从A到B的行，直到大小变为0.但是我做错了什么？大小在第一次发送时是正确的，但不是第二次。

Answer 1

sizof（buf）将返回4，指针的大小，你需要的是strlen（buf）所以

写（pfds [3] [1]，buf，sizeof（buf））;

应该是

写（pfds [3] [1]，buf，strlen（buf））;

通过管道从进程到进程发送缓冲区大小

1 个答案: