modf (3)
Leading comments
Copyright 1993 David Metcalfe (david@prism.demon.co.uk) %%%LICENSE_START(VERBATIM) Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Sin...
NAME
modf, modff, modfl - extract signed integral and fractional values from floating-point numberSYNOPSIS
#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)):
modf(), modfl():
-
_BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE ||
_POSIX_C_SOURCE >= 200112L;
or cc -std=c99
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.