LROUND
Section: Linux Programmer's Manual (3)
Updated: 2013-08-26
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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);
Link with -lm.
Feature Test Macro Requirements for glibc (see
feature_test_macros(7)):
All functions shown above:
-
_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 the
round(3)
and
ceil(3),
functions, 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.
ATTRIBUTES
Multithreading (see pthreads(7))
The
lround(),
lroundf(),
lroundl(),
llround(),
llroundf(),
and
llroundl()
functions are thread-safe.
CONFORMING TO
C99, POSIX.1-2001.
SEE ALSO
ceil(3),
floor(3),
lrint(3),
nearbyint(3),
rint(3),
round(3)
COLOPHON
This page is part of release 3.74 of the Linux
man-pages
project.
A description of the project,
information about reporting bugs,
and the latest version of this page,
can be found at
http://www.kernel.org/doc/man-pages/.
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- RETURN VALUE
-
- ERRORS
-
- VERSIONS
-
- ATTRIBUTES
-
- Multithreading (see pthreads(7))
-
- CONFORMING TO
-
- SEE ALSO
-
- COLOPHON
-