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ualarm(3) [bsd man page]

UALARM(3)						     Library Functions Manual							 UALARM(3)

NAME
ualarm - schedule signal after specified time SYNOPSIS
unsigned ualarm(value, interval) unsigned value; unsigned interval; DESCRIPTION
This is a simplified interface to setitimer(2). Ualarm causes signal SIGALRM, see signal(3C), to be sent to the invoking process in a number of microseconds given by the value argument. Unless caught or ignored, the signal terminates the process. If the interval argument is non-zero, the SIGALRM signal will be sent to the process every interval microseconds after the timer expires (e.g. after value microseconds have passed). Because of scheduling delays, resumption of execution of when the signal is caught may be delayed an arbitrary amount. The longest speci- fiable delay time (on the vax) is 2147483647 microseconds. The return value is the amount of time previously remaining in the alarm clock. SEE ALSO
getitimer(2), setitimer(2), sigpause(2), sigvec(2), signal(3C), sleep(3), alarm(3), usleep(3) NOTES (PDP-11) On the PDP-11, setitimer(2) rounds the number of microseconds up to seconds resolution, therefore ualarm doesn't give you any more resolu- tion than alarm(3). 4.3 Berkeley Distribution August 26, 1988 UALARM(3)

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UALARM(3)						   BSD Library Functions Manual 						 UALARM(3)

NAME
ualarm -- schedule signal after specified time LIBRARY
Standard C Library (libc, -lc) SYNOPSIS
#include <unistd.h> useconds_t ualarm(useconds_t useconds, useconds_t interval); DESCRIPTION
This is a simplified interface to setitimer(2). The ualarm() function waits a count of useconds before asserting the terminating signal SIGALRM. System activity or time used in processing the call may cause a slight delay. If the interval argument is non-zero, the SIGALRM signal will be sent to the process every interval microseconds after the timer expires (e.g., after useconds number of microseconds have passed). Due to a setitimer(2) restriction, the maximum number of useconds and interval is limited to 100,000,000,000,000 (in case this value fits in the unsigned integer). RETURN VALUES
When the signal has successfully been caught, ualarm() returns the amount of time left on the clock. NOTES
A microsecond is 0.000001 seconds. SEE ALSO
getitimer(2), setitimer(2), sigpause(2), sigvec(2), alarm(3), signal(3), sleep(3), usleep(3) HISTORY
The ualarm() function appeared in 4.3BSD. BSD
April 19, 1994 BSD

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