/* $Id: daemonize.c,v 1.12 2011/05/27 09:35:02 nanard Exp $ */ /* MiniUPnP project * http://miniupnp.free.fr/ or http://miniupnp.tuxfamily.org/ * (c) 2006 Thomas Bernard * This software is subject to the conditions detailed * in the LICENCE file provided within the distribution */ #include <sys/types.h> #include <sys/stat.h> #include <unistd.h> #include <fcntl.h> #include <stdio.h> #include <stdlib.h> #include <syslog.h> #include <string.h> #include <signal.h> #include "daemonize.h" #include "config.h" #ifndef USE_DAEMON int daemonize(void) { int pid, i; switch(fork()) { /* fork error */ case -1: perror("fork()"); exit(1); /* child process */ case 0: /* obtain a new process group */ if( (pid = setsid()) < 0) { perror("setsid()"); exit(1); } /* close all descriptors */ for (i=getdtablesize();i>=0;--i) close(i); i = open("/dev/null", O_RDWR); /* open stdin */ dup(i); /* stdout */ dup(i); /* stderr */ umask(027); chdir("/"); /* chdir to /tmp ? */ return pid; /* parent process */ default: exit(0); } } #endif int writepidfile(const char * fname, int pid) { char pidstring[16]; int pidstringlen; int pidfile; if(!fname || (strlen(fname) == 0)) return -1; if( (pidfile = open(fname, O_WRONLY|O_CREAT, 0644)) < 0) { syslog(LOG_ERR, "Unable to open pidfile for writing %s: %m", fname); return -1; } pidstringlen = snprintf(pidstring, sizeof(pidstring), "%d\n", pid); if(pidstringlen <= 0) { syslog(LOG_ERR, "Unable to write to pidfile %s: snprintf(): FAILED", fname); close(pidfile); return -1; } else { if(write(pidfile, pidstring, pidstringlen) < 0) syslog(LOG_ERR, "Unable to write to pidfile %s: %m", fname); } close(pidfile); return 0; } int checkforrunning(const char * fname) { char buffer[64]; int pidfile; pid_t pid; if(!fname || (strlen(fname) == 0)) return -1; if( (pidfile = open(fname, O_RDONLY)) < 0) return 0; memset(buffer, 0, 64); if(read(pidfile, buffer, 63)) { if( (pid = atol(buffer)) > 0) { if(!kill(pid, 0)) { close(pidfile); return -2; } } } close(pidfile); return 0; }