……
// flag variable for debuging
volatile bool g_enable_breakon_sigint = false;
// function for gdb breakpoint
void gdb_breakon_sigint()
{
    printf("A chance to break on SIGINT\n");
}
……
int main(int argc, char **argv)
{
    ……
        // Process signal.
        switch (signal)
        {
            case SIGTERM:
                printf("SIGTERM arrived. Exit now.\n");
                return 0;
            case SIGINT:
                // do not exit if flag is true.
                if (g_enable_breakon_sigint)
                {
                    gdb_breakon_sigint();
                    break;
                }
                printf("SIGINT arrived. Exit now.\n");
                return 0;
            default:
                printf("Unhandled signal [%d]\n", signal);
                break;
        }
    ……
}