Programming

#include <stdio.h> // for File I/O
#include <signal.h> // for signals
#include <unistd.h> // for sleep()

void handler(int signal)
{
    FILE *out=fopen("test.txt","at");
    if (out)
    {
        fprintf(out,"got %d\n",signal);
        fclose(out);
    }
}

int main()
{
    signal(SIGTERM,handler);
    signal(SIGINT,handler);
    sleep(30);
}

#include <stdio.h> // for File I/O
#include <signal.h> // for signals
#include <unistd.h> // for sleep()

void handler(int sig)
{
        /* Just print to stderr and redirect 2>> test.txt in the shell */
    fprintf(stderr, "got %d\n", signal);

    signal(sig, handler); // let signal be caught again
}

int main()
{
    signal(SIGTERM,handler);
    signal(SIGINT,handler);
    signal(SIGQUIT, handler); // Maybe we're getting QUIT first?
    signal(SIGHUP, handler); // If the terminal closes, we might get this
    signal(SIGPIPE, handler); // Don't know why we'd get this, but check anyway
    while(1) // loop forever with most signals trapped, impolitely waiting for a kill -9 ;)
        sleep(30);
}

void handler(int sig)
{
        char buf[128];
        sprintf(buf, "got signal %d\n", sig);
        write(STDERR_FILENO, buf, strlen(buf));
        signal(sig, handler);
}