| NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | CONFORMING TO | SEE ALSO | COLOPHON | The Linux Programming Interface |
MODF(3) Linux Programmer's Manual MODF(3)
modf, modff, modfl - extract signed integral and fractional values from float-
ing-point number
#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
The modf() function breaks 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.
The modf() function returns 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).
No errors occur.
C99, POSIX.1-2001. The variant returning double also conforms to SVr4,
4.3BSD, C89.
frexp(3), ldexp(3)
This page is part of release 3.32 of the Linux man-pages project. A
description of the project, and information about reporting bugs, can be found
at http://www.kernel.org/doc/man-pages/.
2010-09-20 MODF(3)
HTML rendering created 2010-12-03 by Michael Kerrisk, author of The Linux Programming Interface