1.\" $NetBSD: isinff.3,v 1.6 2010/05/14 03:10:24 joerg Exp $ 2.\" 3.\" Copyright (c) 1991, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. Neither the name of the University nor the names of its contributors 15.\" may be used to endorse or promote products derived from this software 16.\" without specific prior written permission. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28.\" SUCH DAMAGE. 29.\" 30.\" from: @(#)isinf.3 8.2 (Berkeley) 1/29/94 31.\" from: NetBSD: isinf.3,v 1.5 1998/08/02 04:52:54 mycroft Exp 32.\" 33.Dd August 16, 1999 34.Dt ISINFF 3 35.Os 36.Sh NAME 37.Nm isinff , 38.Nm isnanf 39.Nd test for infinity or not-a-number 40.Sh LIBRARY 41.Lb libm 42.Sh SYNOPSIS 43.In math.h 44.Ft int 45.Fn isinff float 46.Ft int 47.Fn isnanf float 48.Sh DESCRIPTION 49The 50.Fn isinff 51function 52returns 1 if the number is 53.Dq \*(If , 54otherwise 0. 55.Pp 56The 57.Fn isnanf 58function 59returns 1 if the number is 60.Dq not-a-number , 61otherwise 0. 62.Sh SEE ALSO 63.Xr isinf 3 , 64.Xr isnan 3 , 65.Xr math 3 66.Rs 67.%T "IEEE Standard for Binary Floating-Point Arithmetic" 68.%Q ANSI 69.%R Std 754-1985 70.Re 71.Sh BUGS 72Neither the 73.Tn VAX 74nor the Tahoe floating point have distinguished values 75for either infinity or not-a-number. 76These routines always return 0 on those architectures. 77