alarm(3)
NAME
alarm − schedule signal after specified time
SYNTAX
int alarm(seconds)
int seconds;
DESCRIPTION
The alarm subroutine causes signal SIGALRM, see signal(,), to be sent to the invoking process in a number of seconds given by the argument. Unless caught or ignored, the signal terminates the process.
The alarm requests are not stacked. Successive calls reset the alarm clock. If the argument is 0, any alarm request is canceled. Because of scheduling delays, resumption of execution of when the signal is caught may be delayed an arbitrary amount. The longest specifiable delay time is 2147483647 seconds.
The return value is the amount of time previously remaining in the alarm clock.
ENVIRONMENT
When your program is compiled using the System V environment, alarm takes a parameter of type unsigned, returns a value of type unsigned, and rounds up any positive fraction of a second to the next second.