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dropin.c
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dropin.c
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/*
dropin.c -- a set of drop-in replacements for libc functions
Copyright (C) 2000-2005 Ivo Timmermans,
2000-2022 Guus Sliepen <[email protected]>
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.
*/
#include "system.h"
#ifndef HAVE_ASPRINTF
#include "xalloc.h"
#endif
#ifndef HAVE_DAEMON
/*
Replacement for the daemon() function.
The daemon() function is for programs wishing to detach themselves
from the controlling terminal and run in the background as system
daemons.
Unless the argument nochdir is non-zero, daemon() changes the
current working directory to the root (``/'').
Unless the argument noclose is non-zero, daemon() will redirect
standard input, standard output and standard error to /dev/null.
*/
int daemon(int nochdir, int noclose) {
#ifdef HAVE_FORK
pid_t pid;
int fd;
pid = fork();
/* Check if forking failed */
if(pid < 0) {
perror("fork");
exit(-1);
}
/* If we are the parent, terminate */
if(pid) {
exit(0);
}
/* Detach by becoming the new process group leader */
if(setsid() < 0) {
perror("setsid");
return -1;
}
/* Change working directory to the root (to avoid keeping mount
points busy) */
if(!nochdir) {
chdir("/");
}
/* Redirect stdin/out/err to /dev/null */
if(!noclose) {
fd = open("/dev/null", O_RDWR);
if(fd < 0) {
perror("opening /dev/null");
return -1;
} else {
dup2(fd, 0);
dup2(fd, 1);
dup2(fd, 2);
}
}
return 0;
#else
(void)nochdir;
(void)noclose;
return -1;
#endif
}
#endif
#ifndef HAVE_ASPRINTF
int asprintf(char **buf, const char *fmt, ...) {
int result;
va_list ap;
va_start(ap, fmt);
result = vasprintf(buf, fmt, ap);
va_end(ap);
return result;
}
int vasprintf(char **buf, const char *fmt, va_list ap) {
int status;
va_list aq;
int len;
len = 4096;
*buf = xmalloc(len);
va_copy(aq, ap);
status = vsnprintf(*buf, len, fmt, aq);
va_end(aq);
if(status >= 0) {
*buf = xrealloc(*buf, status + 1);
}
if(status > len - 1) {
len = status + 1;
va_copy(aq, ap);
status = vsnprintf(*buf, len, fmt, aq);
va_end(aq);
}
return status;
}
#endif
#ifndef HAVE_GETTIMEOFDAY
int gettimeofday(struct timeval *tv, void *tz) {
#ifdef HAVE_WINDOWS
FILETIME ft;
GetSystemTimeAsFileTime(&ft);
uint64_t lt = (uint64_t)ft.dwLowDateTime | ((uint64_t)ft.dwHighDateTime << 32);
lt -= 116444736000000000ULL;
tv->tv_sec = lt / 10000000;
tv->tv_usec = (lt / 10) % 1000000;
#else
#warning No high resolution time source!
tv->tv_sec = time(NULL);
tv->tv_usec = 0;
#endif
return 0;
}
#endif
bool sleep_millis(unsigned int ms) {
#ifdef _MSC_VER
Sleep(ms);
return true;
#else
return !usleep(ms * 1000);
#endif
}