1.\" Copyright 2014 Garrett D'Amore <garrett@damore.org> 2.\" Copyright (c) 1980 Regents of the University of California. All rights reserved. The Berkeley software License Agreement specifies the terms and conditions for redistribution. Copyright (c) 2002, Sun Microsystems, Inc. All Rights Reserved Portions Copyright (c) 1992, 3.\" X/Open Company Limited All Rights Reserved 4.\" Sun Microsystems, Inc. gratefully acknowledges The Open Group for permission to reproduce portions of its copyrighted documentation. Original documentation from The Open Group can be obtained online at 5.\" http://www.opengroup.org/bookstore/. 6.\" The Institute of Electrical and Electronics Engineers and The Open Group, have given us permission to reprint portions of their documentation. In the following statement, the phrase "this text" refers to portions of the system documentation. Portions of this text are reprinted and reproduced in electronic form in the Sun OS Reference Manual, from IEEE Std 1003.1, 2004 Edition, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2004 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between these versions and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http://www.opengroup.org/unix/online.html. 7.\" This notice shall appear on any product containing this material. 8.Dd "Aug 16, 2014" 9.Dt UALARM 3C 10.Os 11.Sh NAME 12.Nm ualarm 13.Nd schedule signal after interval in microseconds 14.Sh SYNOPSIS 15.In unistd.h 16.Ft useconds_t 17.Fn ualarm "useconds_t useconds" "useconds_t interval" 18.Sh DESCRIPTION 19The 20.Fn ualarm 21function causes the 22.Dv SIGALRM 23signal to be generated for 24the calling process after the number of real-time microseconds specified by the 25.Fa useconds 26argument has elapsed. 27When the 28.Fa interval 29argument is 30non-zero, repeated timeout notification occurs with a period in microseconds 31specified by the 32.Fa interval 33argument. 34If the notification signal, 35.Dv SIGALRM , 36is not caught or ignored, the calling process is terminated. 37.Lp 38Because of scheduling delays, resumption of execution when the signal is caught 39may be delayed an arbitrary amount of time. 40.Lp 41Interactions between 42.Fn ualarm 43and either 44.Xr alarm 2 45or 46.Xr sleep 3C 47are unspecified. 48.Sh RETURN VALUES 49The 50.Fn ualarm 51function returns the number of microseconds remaining from 52the previous 53.Fn ualarm 54call. 55If no timeouts are pending or if 56.Fn ualarm 57has not previously been called, 58.Fn ualarm 59returns 0. 60.Sh ERRORS 61No errors are defined. 62.Sh USAGE 63The 64.Fn ualarm 65function is a simplified interface to 66.Xr setitimer 2 , 67and uses the 68.Dv ITIMER_REAL 69interval timer. 70It's use has been deprecated in favor of the 71.Xr timer_create 3C 72family of functions. 73.Sh INTERFACE STABILITY 74.Sy Obsolete Standard . 75.Sh SEE ALSO 76.Xr alarm 2 , 77.Xr setitimer 2 , 78.Xr sighold 3C , 79.Xr signal 3C , 80.Xr sleep 3C , 81.Xr timer_create 3C , 82.Xr usleep 3C , 83.Xr unistd.h 3HEAD , 84.Xr standards 5 85.Sh STANDARDS 86The 87.Fn ualarm 88function is available in the following compilation environments. 89See 90.Xr standards 5 . 91.Lp 92.Bl -bullet -compact 93.\".It 94.\".St -p1003.1-90 95.\".It 96.\".St -p1003.1b-93 97.\".It 98.\".St -p1003.1c-95 99.\".It 100.\".St -p1003.1-2001 101.\".It 102.\".St -xpg3 103.\".It 104.\".St -xpg4 105.It 106.St -xpg4.2 107.It 108.St -susv2 109.It 110.St -susv3 111.El 112.Lp 113It is marked obsolete in 114.St -susv3 , and was removed from 115.St -p1003.1-2008 . 116