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():
           _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L;
           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.

ATTRIBUTES
   Multithreading (see pthreads(7))
       The trunc(), truncf(), and truncl() functions are thread-safe.

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 3.74 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/.



                                            2013-06-21                                   TRUNC(3)