Copyright 1993 David Metcalfe (firstname.lastname@example.org) and Copyright 2008, Linux Foundation, written by Michael Kerrisk <email@example.com> %%%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 ...
NAMEfmod, fmodf, fmodl - floating-point remainder function
#include <math.h> double fmod(double x, double y);
float fmodf(float x, float y);
long double fmodl(long double x, long double y);
Link with -lm.
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
_BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE ||
_POSIX_C_SOURCE >= 200112L;
or cc -std=c99
DESCRIPTIONThese functions compute the floating-point remainder of dividing x by y. The return value is x - n * y, where n is the quotient of x / y, rounded toward zero to an integer.
RETURN VALUEOn success, these functions return the value x - n*y, for some integer n, such that the returned value has the same sign as x and a magnitude less than the magnitude of y.
If x or y is a NaN, a NaN is returned.
If x is an infinity, a domain error occurs, and a NaN is returned.
If y is zero, a domain error occurs, and a NaN is returned.
If x is +0 (-0), and y is not zero, +0 (-0) is returned.
ERRORSSee math_error(7) for information on how to determine whether an error has occurred when calling these functions.
The following errors can occur:
- Domain error: x is an infinity
- errno is set to EDOM (but see BUGS). An invalid floating-point exception (FE_INVALID) is raised.
- Domain error: y is zero
- errno is set to EDOM. An invalid floating-point exception (FE_INVALID) is raised.
ATTRIBUTESFor an explanation of the terms used in this section, see attributes(7).
|fmod(), fmodf(), fmodl()||Thread safety||MT-Safe|
CONFORMING TOC99, POSIX.1-2001, POSIX.1-2008.
The variant returning double also conforms to SVr4, 4.3BSD, C89.