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)