abs, labs, llabs, imaxabs — compute the absolute value of an integer
#include <stdlib.h>
int
abs( |
int j) ; |
long int
labs( |
long int j) ; |
long long int
llabs( |
long long int j) ; |
#include <inttypes.h>
intmax_t
imaxabs( |
intmax_t j) ; |
Note | |||
---|---|---|---|
|
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.
Returns the absolute value of the integer argument, of the appropriate integer type for the function.
For an explanation of the terms used in this section, see attributes(7).
Interface | Attribute | Value |
abs (), labs (), llabs (), imaxabs () |
Thread safety | MT-Safe |
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.
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.
This page is part of release 4.07 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/.
Copyright 1993 David Metcalfe (davidprism.demon.co.uk) %%%LICENSE_START(VERBATIM) Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Since the Linux kernel and libraries are constantly changing, this manual page may be incorrect or out-of-date. The author(s) assume no responsibility for errors or omissions, or for damages resulting from the use of the information contained herein. The author(s) may not have taken the same level of care in the production of this manual, which is licensed free of charge, as they might when working professionally. Formatted or processed versions of this manual, if unaccompanied by the source, must acknowledge the copyright and authors of this work. %%%LICENSE_END References consulted: Linux libc source code Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991) 386BSD man pages Modified Mon Mar 29 22:31:13 1993, David Metcalfe Modified Sun Jun 6 23:27:50 1993, David Metcalfe Modified Sat Jul 24 21:45:37 1993, Rik Faith (faithcs.unc.edu) Modified Sat Dec 16 15:02:59 2000, Joseph S. Myers |