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HP-UX Reference > Aalarm(2)HP-UX 11i Version 2: December 2007 Update |
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NAMEalarm() — set a process's alarm clock DESCRIPTIONalarm() instructs the alarm clock of the calling process to send the signal SIGALRM to the calling process after the number of real-time seconds specified by sec have elapsed; see signal(5). Specific implementations might place limitations on the maximum supported alarm time. The constant MAX_ALARM defined in <sys/param.h> specifies the implementation-specific maximum. Whenever sec is greater that this maximum, it is silently rounded down to it. On all implementations, MAX_ALARM is guaranteed to be at least 31 days (in seconds). Alarm requests are not stacked; successive calls reset the alarm clock of the calling process. If sec is 0, any previously made alarm request is canceled. Alarms are not inherited by a child process across a fork(), but are inherited across an exec(). On systems that support the getitimer() and setitimer() system calls, the timer mechanism used by alarm() is the same as that used by ITIMER_REAL. Thus successive calls to alarm(), getitimer(), and setitimer() set and return the state of a single timer. In addition, alarm() sets the timer interval to zero. RETURN VALUEalarm() returns the amount of time previously remaining in the alarm clock of the calling process. |
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