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



NAME
       abs, labs, llabs, imaxabs - compute the absolute value of an integer

SYNOPSIS
       #include <stdlib.h>

       int abs(int j);
       long int labs(long int j);
       long long int llabs(long long int j);

       #include <inttypes.h>

       intmax_t imaxabs(intmax_t j);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       llabs():
           _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L;
           or cc -std=c99

DESCRIPTION
       The  abs()  function  computes  the absolute value of the integer argument j.  The labs(),
       llabs() and imaxabs() functions compute the absolute value of the argument j of the appro‐
       priate integer type for the function.

RETURN VALUE
       Returns  the  absolute  value of the integer argument, of the appropriate integer type for
       the function.

ATTRIBUTES
   Multithreading (see pthreads(7))
       The abs(), labs(), llabs(), and imaxabs() functions are thread-safe.

CONFORMING TO
       SVr4, POSIX.1-2001, 4.3BSD, C99.  C89 only includes the abs() and  labs()  functions;  the
       functions llabs() and imaxabs() were added in C99.

NOTES
       Trying to take the absolute value of the most negative integer is not defined.

       The  llabs()  function  is included in glibc since version 2.0.  The imaxabs() function is
       included in glibc since version 2.1.1.

       For llabs() to be declared, it may be necessary to define _ISOC99_SOURCE or _ISOC9X_SOURCE
       (depending on the version of glibc) before including any standard headers.

       GCC  handles  abs()  and  labs()  as built-in functions.  GCC 3.0 also handles llabs() and
       imaxabs() as built-ins.

SEE ALSO
       cabs(3), ceil(3), fabs(3), floor(3), rint(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/.



GNU                                         2014-08-19                                     ABS(3)