Section: Linux Programmer's Manual (3)Updated: 2010-09-20Local indexUp

NAME

lround, lroundf, lroundl, llround, llroundf, llroundl - round to
nearest integer, away from zero

SYNOPSIS

#include <math.h>long int lround(double x); long int lroundf(float x); long int lroundl(long double x);long long int llround(double x); long long int llroundf(float x); long long int llroundl(long double x);

_XOPEN_SOURCE >= 600 || _ISOC99_SOURCE ||
_POSIX_C_SOURCE >= 200112L;
or
cc -std=c99

DESCRIPTION

These functions round their argument to the nearest integer value,
rounding away from zero,
regardless of the current rounding direction (see
fenv(3)).

Note that unlike
round(3),
ceil(3),
etc., the return type of these functions differs from
that of their arguments.

RETURN VALUE

These functions return the rounded integer value.

If
x
is a NaN or an infinity,
or the rounded value is too large to be stored in a
long
(long long
in the case of the
ll*
functions)
then a domain error occurs, and the return value is unspecified.

ERRORS

See
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 a NaN or infinite, or the rounded value is too large

An invalid floating-point exception
(FE_INVALID)
is raised.

These functions do not set
errno.

VERSIONS

These functions first appeared in glibc in version 2.1.

This page is part of release 3.27 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/.