RINT(3) BSD Programmer's Manual RINT(3)
rint, rintf - round to integral value in floating-point format
libm
#include <math.h> double rint(double x); float rintf(float x);
The rint() function returns the integral value (represented as a double precision number) nearest to x according to the prevailing rounding mode.
abs(3), ceil(3), fabs(3), floor(3), math(3)
A rint() function appeared in Version 6 AT&T UNIX. MirBSD #10-current March 10, 1994 1