minix man page for abs

ABS(3)							     Library Functions Manual							    ABS(3)

NAME
       abs - integer absolute value

SYNOPSIS
       #include <stdlib.h>

       int abs(int i)

DESCRIPTION
       Abs returns the absolute value of its integer operand.

SEE ALSO
       floor(3).

BUGS
       Applying  the  abs  function  to the most negative integer generates a result which is the most negative integer.  That is, abs(0x80000000)
       returns 0x80000000 as a result on a machine with 32-bit ints.  Using the result in unsigned computations is sound however.

7th Edition							   May 15, 1985 							    ABS(3)