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. When the 27.Fa interval 28argument is 29non-zero, repeated timeout notification occurs with a period in microseconds 30specified by the \fIinterval\fR argument. If the notification signal, 31.Dv SIGALRM , 32is not caught or ignored, the calling process is terminated. 33.Lp 34Because of scheduling delays, resumption of execution when the signal is caught 35may be delayed an arbitrary amount of time. 36.Lp 37Interactions between 38.Fn ualarm 39and either 40.Xr alarm 2 41or 42.Xr sleep 3C 43are unspecified. 44.Sh RETURN VALUES 45The 46.Fn ualarm 47function returns the number of microseconds remaining from 48the previous 49.Fn ualarm 50call. If no timeouts are pending or if 51.Fn ualarm 52has not previously been called, 53.Fn ualarm 54returns 0. 55.Sh ERRORS 56No errors are defined. 57.Sh USAGE 58The 59.Fn ualarm 60function is a simplified interface to 61.Xr setitimer 2 , 62and uses the 63.Dv ITIMER_REAL 64interval timer. It's use has been deprecated in favor of the 65.Xr timer_create 3C 66family of functions. 67.Sh INTERFACE STABILITY 68.Sy Obsolete Standard . 69.Sh SEE ALSO 70.Xr alarm 2 , 71.Xr setitimer 2 , 72.Xr sighold 3C , 73.Xr signal 3C , 74.Xr sleep 3C , 75.Xr timer_create 3C , 76.Xr usleep 3C , 77.Xr unistd.h 3HEAD , 78.Xr standards 5 79.Sh STANDARDS 80The 81.Fn ualarm 82function is available in the following compilation environments. See 83.Xr standards 5 . 84.Lp 85.Bl -bullet -compact 86.\".It 87.\".St -p1003.1-90 88.\".It 89.\".St -p1003.1b-93 90.\".It 91.\".St -p1003.1c-95 92.\".It 93.\".St -p1003.1-2001 94.\".It 95.\".St -xpg3 96.\".It 97.\".St -xpg4 98.It 99.St -xpg4.2 100.It 101.St -susv2 102.It 103.St -susv3 104.El 105.Lp 106It is marked obsolete in 107.St -susv3 , and was removed from 108.St -p1003.1-2008 . 109