date and time created 91/03/18 17:01:12 by bostic

[unix-history] / usr / src / lib / libc / gen / isinf.3

.\" Copyright (c) 1991 The Regents of the University of California.
.\" All rights reserved.
.\"
.\" %sccs.include.redist.man%
.\"
.\"     @(#)isinf.3     5.1 (Berkeley) %G%
.\"
.TH ISINF 3 ""
.UC 7
.SH NAME
isinf, isnan \- return if infinity or not-a-number
.SH SYNOPSIS
.nf
.ft B
int isinf(double);
int isnan(double);
.fr R
.fi
.SH DESCRIPTION
.I Isninf
returns 1 if the number is ``infinity'', otherwise 0.
.PP
.I Isnan
returns 1 if the number is ``NaN'', otherwise 0.
.SH SEE ALSO
.IR math (3)
.sp
.IR "IEEE Standard for Binary Floating-Point Arithmetic" ,
ANSI/IEEE Std 754-1985
.SH BUGS
Neither the VAX nor the Tahoe floating point have distinguished values
for either infinity or not-a-number.
These routines always return 0 on those architectures.