abs(3) - Linux manual page (original) (raw)

abs(3) Library Functions Manual abs(3)

NAME top

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

LIBRARY top

   Standard C library (_libc_, _-lc_)

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)](../man7/attributes.7.html).
   ┌──────────────────────────────────────┬───────────────┬─────────┐
   │ **Interface** │ **Attribute** │ **Value** │
   ├──────────────────────────────────────┼───────────────┼─────────┤
   │ **abs**(), **labs**(), **llabs**(), **imaxabs**()    │ Thread safety │ MT-Safe │
   └──────────────────────────────────────┴───────────────┴─────────┘

STANDARDS top

   C11, POSIX.1-2008.

HISTORY top

   POSIX.1-2001, 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 since glibc 2.0.  The **imaxabs**()
   function is included since glibc 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)](../man3/cabs.3.html), [ceil(3)](../man3/ceil.3.html), [fabs(3)](../man3/fabs.3.html), [floor(3)](../man3/floor.3.html), [rint(3)](../man3/rint.3.html)

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Linux man-pages 6.10 2024-07-23 abs(3)

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