How to restart C daemon program in Linux after receiving SIGHUP signal

Question

Can anybody please post some example code on how I can reread a configuration file and restart my daemon after the daemon receives a SIGHUP signal. The daemon is a user spac

Answer 1

I found this page as I was looking for an example myself to make sure I'm doing it correctly. Since there is no example for this I'll post my attempt and let others comment on it:

volatile sig_atomic_t g_eflag = 0;
volatile sig_atomic_t g_hupflag = 1;

static void signal_handler(int sig)
{
    switch(sig)
    {
    case SIGHUP:
        g_hupflag = 1;
        break;
    case SIGINT:
    case SIGTERM:
        g_eflag = 1;
        break;
    }
}

int main(int argc, char **argv)
{
    signal(SIGINT, signal_handler);
    signal(SIGTERM, signal_handler);
    signal(SIGHUP, signal_handler);
    signal(SIGPIPE, SIG_IGN);

    while(!g_eflag)
    {
        if(g_hupflag)
        {
            g_hupflag = 0;
            load_config();
        }

        // ... do daemon work ...
    }

    return 0;
}