1/* vi: set sw=4 ts=4: */
2/*
3 * pid file routines
4 *
5 * Copyright (C) 2007 by Stephane Billiart <stephane.billiart@gmail.com>
6 *
7 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
8 */
9
10/* Override ENABLE_FEATURE_PIDFILE */
11#define WANT_PIDFILE 1
12#include "libbb.h"
13
14smallint wrote_pidfile;
15
16void write_pidfile(const char *path)
17{
18	int pid_fd;
19	char *end;
20	char buf[sizeof(int)*3 + 2];
21	struct stat sb;
22
23	if (!path)
24		return;
25	/* we will overwrite stale pidfile */
26	pid_fd = open(path, O_WRONLY|O_CREAT|O_TRUNC, 0666);
27	if (pid_fd < 0)
28		return;
29
30	/* path can be "/dev/null"! Test for such cases */
31	wrote_pidfile = (fstat(pid_fd, &sb) == 0) && S_ISREG(sb.st_mode);
32
33	if (wrote_pidfile) {
34		/* few bytes larger, but doesn't use stdio */
35		end = utoa_to_buf(getpid(), buf, sizeof(buf));
36		*end = '\n';
37		full_write(pid_fd, buf, end - buf + 1);
38	}
39	close(pid_fd);
40}
41