truncf(3) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | VERSIONS | ATTRIBUTES | CONFORMING TO | NOTES | SEE ALSO | COLOPHON

TRUNC(3)                  Linux Programmer's Manual                 TRUNC(3)

NAME top

       trunc, truncf, truncl - round to integer, toward zero

SYNOPSIS top

       #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 top

       These functions round x to the nearest integer value that is not
       larger in magnitude than x.

RETURN VALUE top

       These functions return the rounded integer value, in floating format.

       If x is integral, infinite, or NaN, x itself is returned.

ERRORS top

       No errors occur.

VERSIONS top

       These functions first appeared in glibc in version 2.1.

ATTRIBUTES top

       For an explanation of the terms used in this section, see
       attributes(7).

       ┌────────────────────────────┬───────────────┬─────────┐
       │Interface                   Attribute     Value   │
       ├────────────────────────────┼───────────────┼─────────┤
       │trunc(), truncf(), truncl() │ Thread safety │ MT-Safe │
       └────────────────────────────┴───────────────┴─────────┘

CONFORMING TO top

       C99, POSIX.1-2001, POSIX.1-2008.

NOTES top

       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 top

       ceil(3), floor(3), lrint(3), nearbyint(3), rint(3), round(3)

COLOPHON top

       This page is part of release 5.08 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)