Путеводитель по Руководству Linux

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   alarm    ( 2 )

установить будильник для подачи сигнала (set an alarm clock for delivery of a signal)

Имя (Name)

alarm - set an alarm clock for delivery of a signal

Синопсис (Synopsis)

#include <unistd.h>

unsigned int alarm(unsigned int seconds);


Описание (Description)

alarm() arranges for a SIGALRM signal to be delivered to the
       calling process in seconds seconds.

If seconds is zero, any pending alarm is canceled.

In any event any previously set alarm() is canceled.


Возвращаемое значение (Return value)

alarm() returns the number of seconds remaining until any
       previously scheduled alarm was due to be delivered, or zero if
       there was no previously scheduled alarm.

Стандарты (Conforming to)

POSIX.1-2001, POSIX.1-2008, SVr4, 4.3BSD.

Примечание (Note)

alarm() and setitimer(2) share the same timer; calls to one will
       interfere with use of the other.

Alarms created by alarm() are preserved across execve(2) and are not inherited by children created via fork(2).

sleep(3) may be implemented using SIGALRM; mixing calls to alarm() and sleep(3) is a bad idea.

Scheduling delays can, as ever, cause the execution of the process to be delayed by an arbitrary amount of time.


Смотри также (See also)

gettimeofday(2), pause(2), select(2), setitimer(2), sigaction(2),
       signal(2), timer_create(2), timerfd_create(2), sleep(3), time(7)