#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <stdlib.h>
#include <stdio.h>
#include <syslog.h>
#include <signal.h>
int daemon_init(void)
{
    pid_t pid;
    if((pid = fork()) < 0) return(-1);
    else if(pid != 0) exit(0); /* parent exit */
    /* child continues */
    setsid(); /* become session leader */
    chdir("/"); /* change working directory */
    umask(0); /* clear file mode creation mask */
    close(0); /* close stdin */
    close(1); /* close stdout */
    close(2); /* close stderr */
    return(0);
}
void sig_term(int signo)
{
    if(signo == SIGTERM)
    /* catched signal sent by kill(1) command */
    {
        syslog(LOG_INFO, "program terminated.");
        closelog(); exit(0);
    }
}
int main(void)
{
    if(daemon_init() == -1)
    {
        printf("can't fork self\n"); exit(0);
    }
    openlog("daemontest", LOG_PID, LOG_USER);
    syslog(LOG_INFO, "program started.");
    signal(SIGTERM, sig_term); /* arrange to catch the signal */
    while(1) { sleep(1); /* put your main program here */ }
    return(0);
}