FMOD(3) Library Functions Manual FMOD(3)

fmod, fmodf, fmodl
floating-point remainder function

Math Library (libm, -lm)

#include <math.h>

double
fmod(double x, double y);

float
fmodf(float x, float y);

long double
fmodl(long double x, long double y);

The fmod() function computes the floating-point remainder of x/ y.

The fmod(), fmodf(), and fmodl() functions return the value x- i*y, for some integer i such that, if y is non-zero, the result has the same sign as x and magnitude less than the magnitude of y. If y is zero, whether a domain error occurs or the fmod() function returns zero is implementation-defined.

math(3)

The fmod() function conforms to ANSI X3.159-1989 (“ANSI C89”).
November 12, 2013 NetBSD 9.0