x11r4 man page for abs

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():
	   _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L

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 appropriate integer type for the function.

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

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

       +----------------------------------+---------------+---------+
       |Interface			  | Attribute	  | Value   |
       +----------------------------------+---------------+---------+
       |abs(), labs(), llabs(), imaxabs() | Thread safety | MT-Safe |
       +----------------------------------+---------------+---------+
CONFORMING TO
       POSIX.1-2001, POSIX.1-2008, C99, SVr4, 4.3BSD.  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.

       By default, GCC handles abs(), labs(), and (since GCC 3.0) llabs() and imaxabs() as built-in functions.

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

COLOPHON
       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/.

GNU
								    2016-03-15								    ABS(3)