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);

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 func-
       tion.

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

CONFORMING TO
       SVID  3, POSIX.1, BSD 4.3, ISO/IEC 9899 (C99).  POSIX.1 (1996 edition)
       only requires  the  abs()  function.   ISO/IEC  9899:1990  (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, but is
       not in libc5 or libc4.  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 builtin functions.  GCC 3.0 also han-
       dles llabs() and imaxabs() as builtins.

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



GNU				  2000-12-17			       ABS(3)