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 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

   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

   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 4.09 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/.

                              2016-03-15                          TRUNC(3)

---

Free and Open Source Software