[LinuxPPS] Patch to make ppsldisc to 'go away' after 60 sec.

[clemens at dwf.com]

After 'playing' with ntp for a while, and starting and restarting it,
I find that I have half a dozen ppsldisc's running.
If anything this is irritating,- and is probably why I reported that
I was having problems with -rc4.

In any case, here is what I do locally.
    1) compile ppsldisc.c and put it in /usr/local/bin
    2) modify the /etc/rc.d/init.d/ntpd startup file, and where it says

        # Start daemon.
        echo -n "Starting ntpd: "
        daemon $NTPD -c $ntpconf
        
I add two lines to make it read

        # Start daemon.
        echo -n "Starting ppsldisc: "
        /usr/local/bin/ppsldisc /dev/ttyS0 &
        echo -n "Starting ntpd: "
        daemon $NTPD -c $ntpconf

I have now modified Rodolfo's ppsldisc with the following minimal patch:

[root at deneb pps]# diff -c ppsldisc.c ppsldisc2.c
*** ppsldisc.c  2008-08-23 15:39:46.000000000 -0600
--- ppsldisc2.c 2008-08-26 10:08:31.000000000 -0600
***************
*** 7,12 ****
--- 7,13 ----
  #include <sys/stat.h>
  #include <fcntl.h>
  #include <string.h>
+ #include <signal.h>
  
  #ifndef N_PPS
  #define N_PPS __N_PPS
***************
*** 19,24 ****
--- 20,30 ----
        exit(EXIT_FAILURE);
  }
  
+ void handler()
+ {
+       exit(0);
+ }
+ 
  int main(int argc, char *argv[])
  {
        int fd;
***************
*** 40,45 ****
--- 46,53 ----
                exit(EXIT_FAILURE);
        }
  
+       signal (SIGALRM, handler);
+       alarm(60);
        pause();
  
        return 0;

---

so that it kills itself after 60 seconds.
Thats WAY longer than its going to take ntpd to get initialized, and
once ntpd is running you no longer ned ppsldisc.

I think this would be a worthwhile change to ppsldisc.c, but that's
up to Rodolfo,- I find it useful.


-- 
                                        Reg.Clemens
                                        reg at dwf.com