Signal begginer

[eomer]

Hello guys

Can anyone explain to me why the kill(my_pid,SIGINT) terminates the programm without executing the line sleep(15) but executing only the printf("Finish\n") ?


thank you

#include <stdio.h>
#include <unistd.h>
#include <sys/socket.h>	
#include <stdlib.h>

void catch_int(int sig_num) {
signal(SIGINT, catch_int);
printf("interrupt \n");
}
 
 int main()
 { 
     
     signal(SIGINT, catch_int);
     int pid;
     pid_t my_pid = getpid();
     
     printf("HELLO \n");
     
     pid=fork();
     if(pid==0)
     {
               printf("CHILD \n");
               kill(my_pid,SIGINT);
               exit(1);
               }
     
     sleep(15);
     printf("Finish\n");        
     return 0;
}

[Mario F.]

I don't know about sockets programming, but that fork() looks suspicious. Can it be sleep() and printf() are being executed by another process? your kill() is followed by an exit(). printf() on that process won't ever run.

[eomer]

I don't know about sockets programming, but that fork() looks suspicious. Can it be sleep() and printf() are being executed by another process? your kill() is followed by an exit(). printf() on that process won't ever run.

exit() terminates the child process. Try to execute to see the results plz

[Mario F.]

I can't right now. But as I said I have no knowledge of sockets programming... and very little of processes. However, the main process keeps running and that one will execute sleep() and printf(), if you don't see it happening try to debug for processes or increase sleep value significantly. 15 miliseconds is hardly something you can see.

[QuestionC]

It's just an implementation detail of sleep. The sleep(15) line is getting executed, it's just getting interrupted too.

The current process is suspended from execution for the
number of seconds specified by the argument. The actual
suspension time may be less than that requested because any
caught signal will terminate the sleep() following execution
of that signal's catching routine.

http://bama.ua.edu/cgi-bin/man-cgi?sleep+3C