MODF
Section: Linux Programmer's Manual (3)
Updated: 2017-09-15
Page Index
NAME
modf, modff, modfl - extract signed integral and fractional values from
floating-point number
SYNOPSIS
#include <math.h>
double modf(double x, double *iptr);
float modff(float x, float *iptr);
long double modfl(long double x, long double *iptr);
Link with -lm.
Feature Test Macro Requirements for glibc (see
feature_test_macros(7)):
modff(),
modfl():
-
_ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
|| /* Since glibc 2.19: */ _DEFAULT_SOURCE
|| /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
DESCRIPTION
These functions break the argument
x
into an integral
part and a fractional part, each of which has the same sign as
x.
The integral part is stored in the location pointed to by
iptr.
RETURN VALUE
These functions return the fractional part of
x.
If
x
is a NaN, a NaN is returned, and
*iptr
is set to a NaN.
If
x
is positive infinity (negative infinity), +0 (-0) is returned, and
*iptr
is set to positive infinity (negative infinity).
ERRORS
No errors occur.
ATTRIBUTES
For an explanation of the terms used in this section, see
attributes(7).
| Interface | Attribute | Value
|
|
modf(),
modff(),
modfl()
| Thread safety | MT-Safe
|
CONFORMING TO
C99, POSIX.1-2001, POSIX.1-2008.
The variant returning
double
also conforms to
SVr4, 4.3BSD, C89.
SEE ALSO
frexp(3),
ldexp(3)
COLOPHON
This page is part of release 5.10 of the Linux
man-pages
project.
A description of the project,
information about reporting bugs,
and the latest version of this page,
can be found at
https://www.kernel.org/doc/man-pages/.