/***
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This file is part of libdaemon.
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Copyright 2003-2008 Lennart Poettering
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Permission is hereby granted, free of charge, to any person obtaining a copy
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of this software and associated documentation files (the "Software"), to deal
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in the Software without restriction, including without limitation the rights
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to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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copies of the Software, and to permit persons to whom the Software is
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furnished to do so, subject to the following conditions:
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The above copyright notice and this permission notice shall be included in
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all copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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SOFTWARE.
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***/
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#ifdef HAVE_CONFIG_H
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#include <config.h>
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#endif
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#include <limits.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <signal.h>
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#include <string.h>
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#include <unistd.h>
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#include <errno.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <time.h>
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#include <sys/select.h>
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#include <fcntl.h>
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#include <stddef.h>
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#include <sys/time.h>
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#include "dpid.h"
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#include "dlog.h"
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#ifndef ETIME
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#define ETIME ETIMEDOUT /* For FreeBSD */
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#endif
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#ifndef PATH_MAX
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#define PATH_MAX 512
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#endif
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#define VARRUN LOCALSTATEDIR "/run"
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const char *daemon_pid_file_ident = NULL;
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daemon_pid_file_proc_t daemon_pid_file_proc = daemon_pid_file_proc_default;
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const char *daemon_pid_file_proc_default(void) {
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#ifdef HAVE_ASPRINTF
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static char *fn = NULL;
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free(fn);
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asprintf(&fn, "%s/%s.pid", VARRUN, daemon_pid_file_ident ? daemon_pid_file_ident : "unknown");
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#else
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static char fn[PATH_MAX];
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snprintf(fn, sizeof(fn), "%s/%s.pid", VARRUN, daemon_pid_file_ident ? daemon_pid_file_ident : "unknown");
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#endif
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return fn;
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}
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static int lock_file(int fd, int enable) {
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struct flock f;
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memset(&f, 0, sizeof(f));
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f.l_type = enable ? F_WRLCK : F_UNLCK;
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f.l_whence = SEEK_SET;
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f.l_start = 0;
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f.l_len = 0;
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if (fcntl(fd, F_SETLKW, &f) < 0) {
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if (enable && errno == EBADF) {
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f.l_type = F_RDLCK;
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if (fcntl(fd, F_SETLKW, &f) >= 0)
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return 0;
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}
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daemon_log(LOG_WARNING, "fcntl(F_SETLKW) failed: %s", strerror(errno));
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return -1;
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}
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return 0;
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}
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pid_t daemon_pid_file_is_running(void) {
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const char *fn;
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static char txt[256];
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int fd = -1, locked = -1;
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pid_t ret = (pid_t) -1, pid;
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ssize_t l;
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long lpid;
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char *e = NULL;
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if (!(fn = daemon_pid_file_proc())) {
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errno = EINVAL;
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goto finish;
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}
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if ((fd = open(fn, O_RDWR, 0644)) < 0) {
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if ((fd = open(fn, O_RDONLY, 0644)) < 0) {
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if (errno != ENOENT)
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daemon_log(LOG_WARNING, "Failed to open PID file: %s", strerror(errno));
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goto finish;
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}
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}
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if ((locked = lock_file(fd, 1)) < 0)
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goto finish;
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if ((l = read(fd, txt, sizeof(txt)-1)) < 0) {
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int saved_errno = errno;
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daemon_log(LOG_WARNING, "read(): %s", strerror(errno));
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unlink(fn);
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errno = saved_errno;
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goto finish;
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}
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txt[l] = 0;
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txt[strcspn(txt, "\r\n")] = 0;
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errno = 0;
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lpid = strtol(txt, &e, 10);
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pid = (pid_t) lpid;
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if (errno != 0 || !e || *e || (long) pid != lpid) {
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daemon_log(LOG_WARNING, "PID file corrupt, removing. (%s)", fn);
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unlink(fn);
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errno = EINVAL;
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goto finish;
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}
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if (kill(pid, 0) != 0 && errno != EPERM) {
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int saved_errno = errno;
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daemon_log(LOG_WARNING, "Process %lu died: %s; trying to remove PID file. (%s)", (unsigned long) pid, strerror(errno), fn);
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unlink(fn);
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errno = saved_errno;
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goto finish;
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}
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ret = pid;
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finish:
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if (fd >= 0) {
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int saved_errno = errno;
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if (locked >= 0)
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lock_file(fd, 0);
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close(fd);
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errno = saved_errno;
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}
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return ret;
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}
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int daemon_pid_file_kill(int s) {
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pid_t pid;
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if ((pid = daemon_pid_file_is_running()) == (pid_t) -1)
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return -1;
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if (kill(pid, s) < 0)
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return -1;
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return 0;
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}
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int daemon_pid_file_kill_wait(int s, int m) {
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pid_t pid;
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time_t t;
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if ((pid = daemon_pid_file_is_running()) < 0)
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return -1;
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if (kill(pid, s) < 0)
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return -1;
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t = time(NULL) + m;
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for (;;) {
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int r;
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struct timeval tv = { 0, 100000 };
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if (time(NULL) > t) {
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errno = ETIME;
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return -1;
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}
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if ((r = kill(pid, 0)) < 0 && errno != ESRCH)
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return -1;
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if (r)
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return 0;
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if (select(0, NULL, NULL, NULL, &tv) < 0)
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return -1;
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}
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}
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int daemon_pid_file_create(void) {
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const char *fn;
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int fd = -1;
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int ret = -1;
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int locked = -1;
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char t[64];
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ssize_t l;
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mode_t u;
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u = umask(022);
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if (!(fn = daemon_pid_file_proc())) {
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errno = EINVAL;
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goto finish;
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}
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if ((fd = open(fn, O_CREAT|O_RDWR|O_EXCL, 0644)) < 0) {
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daemon_log(LOG_ERR, "open(%s): %s", fn, strerror(errno));
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goto finish;
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}
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if ((locked = lock_file(fd, 1)) < 0) {
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int saved_errno = errno;
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unlink(fn);
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errno = saved_errno;
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goto finish;
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}
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snprintf(t, sizeof(t), "%lu\n", (unsigned long) getpid());
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l = strlen(t);
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if (write(fd, t, l) != l) {
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int saved_errno = errno;
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daemon_log(LOG_WARNING, "write(): %s", strerror(errno));
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unlink(fn);
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errno = saved_errno;
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goto finish;
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}
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ret = 0;
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finish:
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if (fd >= 0) {
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int saved_errno = errno;
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if (locked >= 0)
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lock_file(fd, 0);
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close(fd);
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errno = saved_errno;
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}
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umask(u);
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return ret;
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}
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int daemon_pid_file_remove(void) {
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const char *fn;
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if (!(fn = daemon_pid_file_proc())) {
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errno = EINVAL;
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return -1;
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}
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return unlink(fn);
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}
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