Daemonize your code

If you write a shell script or program and need to fork it to the background as a daemon there could be some issues. The normal standard daemon library may not be able to totally disconnect from any open file descriptors. This simple C++ program can do it all for you and it is so easy to use, just put this program in front of your normal command and it will turn any normal program in to a system level daemon.

#include <sys/types.h>
#include <sys/stat.h>
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <errno.h>
#include <unistd.h>
#include <syslog.h>
#include <string.h>

int main(int argc, char *argv[]) {
 int i;
 // int reterr;
 pid_t pid, sid;
 
 //Fork the Parent Process
 pid = fork();
 
 if (pid < 0) { exit(EXIT_FAILURE); }
 
 //We got a good pid, Close the Parent Process
 if (pid > 0) { exit(EXIT_SUCCESS); }
 
 //Change File Mask
 umask(0);
 
 //Create a new Signature Id for our child
 sid = setsid();
 if (sid < 0) { exit(EXIT_FAILURE); }
 
 //Change Directory
 //If we cant find the directory we exit with failure.
 if ((chdir("/")) < 0) { exit(EXIT_FAILURE); }
 
 //Close Standard File Descriptors
 close(STDIN_FILENO);
 close(STDOUT_FILENO);
 close(STDERR_FILENO);
 
 //----------------
 //Main Process
 //----------------
 for(i=0; i < argc - 1; i++) {
  argv[i]=argv[i+1];
 }
 argv[argc-1] = '\0';
 execv(argv[0], argv);
 //reterr = execv(argv[0], argv);
 //printf("execv failed with '%s'\n", strerror(errno));

 //Close the log
 closelog ();
}