void os_exit(int exit_code) __attribute__((noreturn));
/**
+ * os_alarm() - access to the OS alarm() system call
+ *
+ * @seconds: number of seconds before the signal is sent
+ * Returns: number of seconds remaining until any previously scheduled alarm was
+ * due to be delivered; 0 if there was no previously scheduled alarm
+ */
+unsigned int os_alarm(unsigned int seconds);
+
+/**
+ * os_set_alarm_handler() - set handler for SIGALRM
+ *
+ * @handler: The handler function. Pass NULL for SIG_DFL.
+ */
+void os_set_alarm_handler(void (*handler)(int));
+
+/**
+ * os_raise_sigalrm() - do raise(SIGALRM)
+ */
+void os_raise_sigalrm(void);
+
+/**
* os_tty_raw() - put tty into raw mode to mimic serial console better
*
* @fd: File descriptor of stdin (normally 0)