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 not larger in absolute
       value.

RETURN VALUE         top

       These functions return the rounded integer value.

       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 4.15 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/.

                                 2017-09-15                         TRUNC(3)

Pages that refer to this page: ceil(3),  floor(3),  rint(3),  round(3)

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