FMOD(3M) Mathematical Library Functions FMOD(3M)

fmod, fmodf, fmodl - floating-point remainder value function

c99 [ flag... ] file... -lm [ library... ]
#include <math.h>
double fmod(double x, double y);

float fmodf(float x, float y);

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

These functions return the floating-point remainder of the division of x by y.

These functions return the value xi * 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 x or y is NaN, a NaN is returned.

If y is 0, a domain error occurs and a NaN is returned.

If x is infinite, a domain error occurs and a NaN is returned.

If x is ±0 and y is not 0, ±0 is returned.

If x is not infinite and y is ±Inf, x is returned.

These functions will fail if:

Domain Error

The x argument is infinite or y is 0.

If the integer expression (math_errhandling & MATH_ERREXCEPT) is non-zero, the invalid floating-point exception is raised.

An application wanting to check for exceptions should call feclearexcept(FE_ALL_EXCEPT) before calling these functions. On return, if fetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW) is non-zero, an exception has been raised. An application should either examine the return value or check the floating point exception flags to detect exceptions.

See attributes(7) for descriptions of the following attributes:

Interface Stability Standard
MT-Level MT-Safe

math.h(3HEAD), feclearexcept(3M), fetestexcept(3M), isnan(3M), attributes(7), standards(7)

July 12, 2006 SunOS 5.11