#define ALARM 14
main(argc, argv)
char **argv;
{
int c, n;
char *s;
extern awake();
n = 0;
if(argc < 2) {
prints("Usage: sleep seconds\n");
exit(1);
}
s = argv[1];
while(c = *s++) {
if(c<'0' || c>'9') {
printf("non-numeric argument\n");
exit(1);
}
n = n*10 + c - '0';
}
if (n == 0) exit(0);
signal(ALARM, awake);
alarm(n);
pause();
}
awake() {
exit(0);
}
prints(s)
char *s;
{
while(*s)
write(2, s++, 1);
}