tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Write in a pipe and wait.
4 *
5 * Used by layout1.umount_sandboxer from fs_test.c
6 *
7 * Copyright © 2024-2025 Microsoft Corporation
8 */
9
10#define _GNU_SOURCE
11#include <stdio.h>
12#include <stdlib.h>
13#include <unistd.h>
14
15int main(int argc, char *argv[])
16{
17 int pipe_child, pipe_parent;
18 char buf;
19
20 /* The first argument must be the file descriptor number of a pipe. */
21 if (argc != 3) {
22 fprintf(stderr, "Wrong number of arguments (not two)\n");
23 return 1;
24 }
25
26 pipe_child = atoi(argv[1]);
27 pipe_parent = atoi(argv[2]);
28
29 /* Signals that we are waiting. */
30 if (write(pipe_child, ".", 1) != 1) {
31 perror("Failed to write to first argument");
32 return 1;
33 }
34
35 /* Waits for the parent do its test. */
36 if (read(pipe_parent, &buf, 1) != 1) {
37 perror("Failed to write to the second argument");
38 return 1;
39 }
40
41 return 0;
42}