Application Heartbeat Monitor

There might be a standard POSIX way of doing it, but on Linux I think you can do something along the lines of:

<pseudo-code>
pid = pid_of_program();
fd = fd_to_get_name_of();
char buf[1024];
snprintf(buf, 1024, "/proc/%d/fd/%d", pid, fd);
readlink(buf, buf, 1024);
printf("fd %d in pid %d maps to %s\n", fd, pid, buf);
</pseudo-code>