abs(3) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ATTRIBUTES | CONFORMING TO | NOTES | SEE ALSO | COLOPHON

ABS(3)                  Linux Programmer's Manual                 ABS(3)

NAME         top

       abs, labs, llabs, imaxabs - compute the absolute value of an
       integer

SYNOPSIS         top

       #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         top

       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         top

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

ATTRIBUTES         top

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

       ┌───────────────────┬───────────────┬─────────┐
       │Interface          Attribute     Value   │
       ├───────────────────┼───────────────┼─────────┤
       │abs(), labs(),     │ Thread safety │ MT-Safe │
       │llabs(), imaxabs() │               │         │
       └───────────────────┴───────────────┴─────────┘

CONFORMING TO         top

       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         top

       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         top

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

COLOPHON         top

       This page is part of release 5.10 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                            2020-11-01                         ABS(3)

Pages that refer to this page: cabs(3)div(3)fabs(3)strtoimax(3)wcstoimax(3)