1 .\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk)
2 .\" and Copyright 2008, Linux Foundation, written by Michael Kerrisk
3 .\" <mtk.manpages@gmail.com>
5 .\" Permission is granted to make and distribute verbatim copies of this
6 .\" manual provided the copyright notice and this permission notice are
7 .\" preserved on all copies.
9 .\" Permission is granted to copy and distribute modified versions of this
10 .\" manual under the conditions for verbatim copying, provided that the
11 .\" entire resulting derived work is distributed under the terms of a
12 .\" permission notice identical to this one.
14 .\" Since the Linux kernel and libraries are constantly changing, this
15 .\" manual page may be incorrect or out-of-date. The author(s) assume no
16 .\" responsibility for errors or omissions, or for damages resulting from
17 .\" the use of the information contained herein. The author(s) may not
18 .\" have taken the same level of care in the production of this manual,
19 .\" which is licensed free of charge, as they might when working
22 .\" Formatted or processed versions of this manual, if unaccompanied by
23 .\" the source, must acknowledge the copyright and authors of this work.
25 .\" References consulted:
26 .\" Linux libc source code
27 .\" Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991)
29 .\" Modified 1993-07-24 by Rik Faith (faith@cs.unc.edu)
30 .\" Modified 2002-07-27 by Walter Harms
31 .\" (walter.harms@informatik.uni-oldenburg.de)
33 .TH FMOD 3 2010-09-20 "" "Linux Programmer's Manual"
35 fmod, fmodf, fmodl \- floating-point remainder function
40 .BI "double fmod(double " x ", double " y );
42 .BI "float fmodf(float " x ", float " y );
44 .BI "long double fmodl(long double " x ", long double " y );
50 Feature Test Macro Requirements for glibc (see
51 .BR feature_test_macros (7)):
58 _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE\ >=\ 600 || _ISOC99_SOURCE ||
59 _POSIX_C_SOURCE\ >=\ 200112L;
68 function computes the floating-point remainder of dividing \fIx\fP by
70 The return value is \fIx\fP \- \fIn\fP * \fIy\fP, where \fIn\fP
71 is the quotient of \fIx\fP / \fIy\fP, rounded toward zero to an integer.
74 functions return the value \fIx\fP\ \-\ \fIn\fP*\fIy\fP,
75 for some integer \fIn\fP,
76 such that the returned value has the same sign as
78 and a magnitude less than the magnitude of
85 is a NaN, a NaN is returned.
90 a domain error occurs, and
96 a domain error occurs, and
103 is not zero, +0 (\-0) is returned.
107 for information on how to determine whether an error has occurred
108 when calling these functions.
110 The following errors can occur:
112 Domain error: \fIx\fP is an infinity
117 An invalid floating-point exception
121 Domain error: \fIy\fP is zero
125 An invalid floating-point exception
128 .\" POSIX.1 documents an optional underflow error, but AFAICT it doesn't
129 .\" (can't?) occur -- mtk, Jul 2008
131 Before version 2.10, the glibc implementation did not set
132 .\" http://sources.redhat.com/bugzilla/show_bug.cgi?id=6784
136 when a domain error occurred for an infinite
140 The variant returning