1 .\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk)
3 .\" %%%LICENSE_START(VERBATIM)
4 .\" Permission is granted to make and distribute verbatim copies of this
5 .\" manual provided the copyright notice and this permission notice are
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8 .\" Permission is granted to copy and distribute modified versions of this
9 .\" manual under the conditions for verbatim copying, provided that the
10 .\" entire resulting derived work is distributed under the terms of a
11 .\" permission notice identical to this one.
13 .\" Since the Linux kernel and libraries are constantly changing, this
14 .\" manual page may be incorrect or out-of-date. The author(s) assume no
15 .\" responsibility for errors or omissions, or for damages resulting from
16 .\" the use of the information contained herein. The author(s) may not
17 .\" have taken the same level of care in the production of this manual,
18 .\" which is licensed free of charge, as they might when working
21 .\" Formatted or processed versions of this manual, if unaccompanied by
22 .\" 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 MODF 3 2010-09-20 "" "Linux Programmer's Manual"
35 modf, modff, modfl \- extract signed integral and fractional values from
41 .BI "double modf(double " x ", double *" iptr );
43 .BI "float modff(float " x ", float *" iptr );
45 .BI "long double modfl(long double " x ", long double *" iptr );
51 Feature Test Macro Requirements for glibc (see
52 .BR feature_test_macros (7)):
59 _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE\ >=\ 600 || _ISOC99_SOURCE ||
60 _POSIX_C_SOURCE\ >=\ 200112L;
69 function breaks the argument \fIx\fP into an integral
70 part and a fractional part, each of which has the same sign as \fIx\fP.
71 The integral part is stored in the location pointed to by \fIiptr\fP.
75 function returns the fractional part of \fIx\fP.
79 is a NaN, a NaN is returned, and
85 is positive infinity (negative infinity), +0 (\-0) is returned, and
87 is set to positive infinity (negative infinity).