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/*************************************************************************** |
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* Copyright (C) 2006 by Torben H. Nielsen * |
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* torben@t-hoerup.dk * |
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* * |
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* This program is free software; you can redistribute it and/or modify * |
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* it under the terms of the GNU General Public License as published by * |
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* the Free Software Foundation; either version 2 of the License, or * |
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* (at your option) any later version. * |
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* * |
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* This program is distributed in the hope that it will be useful, * |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of * |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * |
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* GNU General Public License for more details. * |
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* * |
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* You should have received a copy of the GNU General Public License * |
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* along with this program; if not, write to the * |
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* Free Software Foundation, Inc., * |
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* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. * |
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***************************************************************************/ |
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|
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/* daemon.[hc] indeholder alle daemon relaterede functioner incl. |
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* getConfig(); |
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* daemonize(); |
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* writelog(); |
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*/ |
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|
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#include <stdlib.h> |
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#include <stdio.h> |
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#include <fcntl.h> |
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#include <signal.h> |
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#include <unistd.h> |
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#include <string.h> |
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#include <time.h> |
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#include <sys/types.h> |
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#include <sys/stat.h> |
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|
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#include "daemon.h" |
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|
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|
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static const char *months[] = { |
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"Jan","Feb","Mar","Apr","May","Jun", |
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"Jul","Aug","Sep","Oct","Nov","Dec" |
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}; |
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|
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// write message to the logfile |
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void log_message(char *message) |
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{ |
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FILE *logfile; |
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char buf[30]; |
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long n = time(NULL); |
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struct tm *now; |
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now = localtime(&n); |
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|
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sprintf(buf, "%02d:%02d:%02d %s %02d %02d", |
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now->tm_hour, now->tm_min, now->tm_sec,months[now->tm_mon], |
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now->tm_mday,now->tm_year % 100); |
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|
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if (CONFIG->debug) { |
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printf("%s: %s\n", buf, message); |
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fflush(stdout); |
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} else { |
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logfile = fopen(CONFIG->logfile, "a"); |
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if (!logfile) |
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return; |
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fprintf(logfile, "%s: %s\n", buf, message); |
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fclose(logfile); |
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} |
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} |
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|
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|
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void signal_handler(int sig) |
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{ |
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switch(sig) { |
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case SIGHUP: |
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log_message("hangup signal catched"); |
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break; |
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case SIGTERM: |
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log_message("terminate signal catched...exiting"); |
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unlink(CONFIG->lock); |
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daemon_shutdown(0); |
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break; |
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} |
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} |
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|
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|
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void daemonize() |
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{ |
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int i, lfp; |
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char str[10]; |
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|
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if (getppid() == 1) /* already a daemon */ |
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return; |
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|
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i=fork(); |
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|
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if (i<0) /* fork error */ |
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daemon_shutdown(FORK_ERROR); |
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if (i>0) /* parent exits */ |
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daemon_shutdown(0); |
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/* child daemon continues */ |
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|
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setsid(); /* obtain a new process group */ |
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|
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for (i=getdtablesize(); i>=0; --i) |
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close(i); /*close all descriptors*/ |
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|
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i=open("/dev/null", O_RDWR); /* handle std. io */ |
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dup(i); |
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dup(i); |
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|
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umask(027); /* set newly created file permissions */ |
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|
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chdir(CONFIG->rundir); /* change running directory*/ |
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|
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//attempt to create lockfile and put a file-lock on it |
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lfp=open(CONFIG->lock, O_RDWR|O_CREAT, 0640); |
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if (lfp<0) /* can not open */ |
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daemon_shutdown(CANT_OPEN_LOCK); |
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if (lockf(lfp,F_TLOCK,0) < 0) /* can not lock */ |
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daemon_shutdown(ALREADY_LOCKED); |
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|
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/* first instance continues */ |
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sprintf(str, "%d\n", getpid() ); /* record pid to lockfile */ |
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write(lfp, str, strlen(str) ); |
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signal(SIGCHLD, SIG_IGN); /* ignore child */ |
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signal(SIGTSTP, SIG_IGN); /* ignore tty signals */ |
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signal(SIGTTOU, SIG_IGN); |
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signal(SIGTTIN, SIG_IGN); |
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signal(SIGHUP, signal_handler); /* catch hangup signal */ |
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signal(SIGTERM, signal_handler); /* catch kill signal */ |
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log_message("downloadd started ..."); |
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} |
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|
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|
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void read_config_file(char *configfile) { |
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char buf[120]; |
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FILE *input = 0; |
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int pos; |
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char *cptr; |
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|
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// first populate config with default values |
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strcpy(CONFIG->logfile, "/tmp/downloadd.log"); |
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strcpy(CONFIG->lock, "/tmp/downloadd.lock"); |
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strcpy(CONFIG->rundir, "/tmp"); |
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|
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strcpy(CONFIG->dbuser, "myuser"); |
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strcpy(CONFIG->dbpass, "mypass"); |
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strcpy(CONFIG->dbhost, "localhost"); |
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strcpy(CONFIG->dbname, "downloadd"); |
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CONFIG->dbport = 3306; |
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|
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// first try to open the file |
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if (configfile && strlen(configfile) >0) { |
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input = fopen(configfile, "r"); |
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|
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if (input) { |
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while (!feof(input)) { |
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fgets(buf, 120, input); |
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|
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pos = strlen(buf); |
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if (strlen(buf)>0 && buf[pos-1] == '\n') |
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buf[pos-1] = 0; //ignore trailing newline |
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|
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if (strlen(buf)==0 || buf[0] == '#' || buf[0] == ';') |
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continue; |
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cptr = strchr(buf, ' '); |
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cptr++; |
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if(strncmp(buf,"logfile ",8)==0) { |
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strcpy(CONFIG->logfile, cptr); |
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} else if (strncmp(buf,"lock ",5)==0) { |
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strcpy(CONFIG->lock, cptr); |
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} else if (strncmp(buf, "rundir ",7)==0) { |
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strcpy(CONFIG->rundir, cptr); |
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} else if (strncmp(buf, "dbuser ",7)==0) { |
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strcpy(CONFIG->dbuser,cptr); |
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} else if (strncmp(buf, "dbpass ",7)==0) { |
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strcpy(CONFIG->dbpass,cptr); |
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} else if (strncmp(buf, "dbhost ",7)==0) { |
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strcpy(CONFIG->dbhost,cptr); |
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} else if (strncmp(buf, "dbname ",7)==0) { |
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strcpy(CONFIG->dbname,cptr); |
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} else if (strncmp(buf, "dbport ",7)==0) { |
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CONFIG->dbport = atoi(cptr); |
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} else { |
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printf("unknown config directive: %s\n", buf); |
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fflush(stdout); |
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} |
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//make the buffer look empty |
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buf[0] = 0; |
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} |
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} else { |
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sprintf(buf,"Could not open config file %s, using default values.", configfile); |
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log_message(buf); |
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} |
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} else { |
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log_message( "No config file specified. Using default values."); |
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} |
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|
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//at the end we should at least validate lock, logfile & rundir |
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} |
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|
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void daemon_shutdown(int errorlevel) { |
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log_message("Shutting down..."); |
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exit(errorlevel); |
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} |
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