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 labs(long j);
       long long llabs(long long 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 argu‐
       ment 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)

GNU                                                                            2021-03-22                                                                         ABS(3)