abs(3)                     Library Functions Manual                     abs(3)

NAME
       abs, labs, llabs, imaxabs, uabs, ulabs, ullabs, uimaxabs - compute the
       absolute value of an integer

LIBRARY
       Standard C library (libc, -lc)

SYNOPSIS
       #include <stdlib.h>

       int abs(int j);
       long labs(long j);
       long long llabs(long long j);

       unsigned int uabs(int j);
       unsigned long ulabs(long j);
       unsigned long long ullabs(long long j);

       #include <inttypes.h>

       intmax_t imaxabs(intmax_t j);
       uintmax_t uimaxabs(intmax_t j);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       llabs():
           _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L

       uabs(), ulabs(), ullabs(), uimaxabs():
           _ISOC2Y_SOURCE

DESCRIPTION
       These functions compute the absolute value of the argument 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 (), uabs | Thread safety | MT-Safe |
       |(), ulabs (), ullabs (), uimaxabs ()        |               |         |
       +--------------------------------------------+---------------+---------+
STANDARDS
       abs()
       labs()
       llabs()
       imaxabs()
              C23, POSIX.1-2024

HISTORY
       abs()  C89, POSIX.1-1996, SVr4, 4.3BSD.

       labs() C89, POSIX.1-2001.

       llabs()
              C99, POSIX.1-2001; glibc 2.0.

       imaxabs()
              C99, POSIX.1-2001; glibc 2.1.1.

       uabs()
       ulabs()
       ullabs()
       uimaxabs()
              C2y; glibc 2.42.

BUGS
       For abs(), labs(), llabs(), and imaxabs(), trying to take the absolute
       value of the most negative integer is not defined.

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

Linux man-pages 6.14              2025-05-06                            abs(3)