NAME¶

trunc, truncf, truncl - round to integer, towards 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(): _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE; or cc -std=c99

DESCRIPTION¶

These functions round x to the nearest integer not larger in absolute value.

RETURN VALUE¶

These functions return the rounded integer value.

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.

CONFORMING TO¶

C99, POSIX.1-2001.

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 3.22 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/.