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/*
* Copyright 2003-2017 The Music Player Daemon Project
* http://www.musicpd.org
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef MPD_PID_FILE_HXX
#define MPD_PID_FILE_HXX
#include "fs/FileSystem.hxx"
#include "fs/AllocatedPath.hxx"
#include "Log.hxx"
#include <assert.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <fcntl.h>
class PidFile {
int fd;
public:
PidFile(const AllocatedPath &path):fd(-1) {
if (path.IsNull())
return;
fd = OpenFile(path, O_WRONLY|O_CREAT|O_TRUNC, 0666);
if (fd < 0) {
const std::string utf8 = path.ToUTF8();
FormatFatalSystemError("Failed to create pid file \"%s\"",
utf8.c_str());
}
}
PidFile(const PidFile &) = delete;
void Close() {
if (fd < 0)
return;
close(fd);
}
void Delete(const AllocatedPath &path) {
if (fd < 0) {
assert(path.IsNull());
return;
}
assert(!path.IsNull());
close(fd);
unlink(path.c_str());
}
void Write(pid_t pid) {
if (fd < 0)
return;
char buffer[64];
sprintf(buffer, "%lu\n", (unsigned long)pid);
write(fd, buffer, strlen(buffer));
close(fd);
}
void Write() {
if (fd < 0)
return;
Write(getpid());
}
};
gcc_pure
static inline pid_t
ReadPidFile(Path path) noexcept
{
int fd = OpenFile(path, O_RDONLY, 0);
if (fd < 0)
return -1;
pid_t pid = -1;
char buffer[32];
auto nbytes = read(fd, buffer, sizeof(buffer) - 1);
if (nbytes > 0) {
buffer[nbytes] = 0;
char *endptr;
auto value = strtoul(buffer, &endptr, 10);
if (endptr > buffer)
pid = value;
}
close(fd);
return pid;
}
#endif
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