1.\" $OpenBSD: frexp.3,v 1.8 2007/05/31 19:19:28 jmc Exp $ 2.\" 3.\" Copyright (c) 1991, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" This code is derived from software contributed to Berkeley by 7.\" the American National Standards Committee X3, on Information 8.\" Processing Systems. 9.\" 10.\" Redistribution and use in source and binary forms, with or without 11.\" modification, are permitted provided that the following conditions 12.\" are met: 13.\" 1. Redistributions of source code must retain the above copyright 14.\" notice, this list of conditions and the following disclaimer. 15.\" 2. Redistributions in binary form must reproduce the above copyright 16.\" notice, this list of conditions and the following disclaimer in the 17.\" documentation and/or other materials provided with the distribution. 18.\" 3. Neither the name of the University nor the names of its contributors 19.\" may be used to endorse or promote products derived from this software 20.\" without specific prior written permission. 21.\" 22.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32.\" SUCH DAMAGE. 33.\" 34.Dd $Mdocdate: May 31 2007 $ 35.Dt FREXP 3 36.Os 37.Sh NAME 38.Nm frexp 39.Nd convert floating-point number to fractional and integral components 40.Sh SYNOPSIS 41.Fd #include <math.h> 42.Ft double 43.Fn frexp "double value" "int *exp" 44.Sh DESCRIPTION 45The 46.Fn frexp 47function breaks a floating-point number into a normalized 48fraction and an integral power of 2. 49It stores the integer in the 50.Li int 51object pointed to by 52.Fa exp . 53.Sh RETURN VALUES 54The 55.Fn frexp 56function returns the value 57.Li x , 58such that 59.Li x 60is a 61.Li double 62with magnitude in the interval [1/2,\ 1) or zero, and 63.Fa value 64equals 65.Li x 66times 2 raised to the power 67.Fa *exp . 68If 69.Fa value 70is zero, both parts of the result are zero. 71.Sh SEE ALSO 72.Xr ldexp 3 , 73.Xr math 3 , 74.Xr modf 3 75.Sh STANDARDS 76The 77.Fn frexp 78function conforms to 79.St -ansiC . 80