TRUNC(3) Linux Programmer's Manual TRUNC(3)
NAME
trunc, truncf, truncl - round to integer, toward zero
SYNOPSIS
#include <math.h>
double trunc(double x);
float truncf(float x);
long double truncl(long double x);
Link with -lm.
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
trunc(), truncf(), truncl():
_ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
DESCRIPTION
These functions round x to the nearest integer value that is not larger
in magnitude than x.
RETURN VALUE
These functions return the rounded integer value, in floating format.
If x is integral, infinite, or NaN, x itself is returned.
ERRORS
No errors occur.
VERSIONS
These functions first appeared in glibc in version 2.1.
ATTRIBUTES
For an explanation of the terms used in this section, see at-
tributes(7).
+----------------------------+---------------+---------+
|Interface | Attribute | Value |
+----------------------------+---------------+---------+
|trunc(), truncf(), truncl() | Thread safety | MT-Safe |
+----------------------------+---------------+---------+
CONFORMING TO
C99, POSIX.1-2001, POSIX.1-2008.
NOTES
The integral value returned by these functions may be too large to
store in an integer type (int, long, etc.). To avoid an overflow,
which will produce undefined results, an application should perform a
range check on the returned value before assigning it to an integer
type.
SEE ALSO
ceil(3), floor(3), lrint(3), nearbyint(3), rint(3), round(3)
COLOPHON
This page is part of release 5.07 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
https://www.kernel.org/doc/man-pages/.
2019-03-06 TRUNC(3)