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 int labs(long int j);
long long int llabs(long long int 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 argument j of the appropriate integer type for the func‐
tion.
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(), │ Thread safety │ MT-Safe │
│llabs(), imaxabs() │ │ │
└───────────────────┴───────────────┴─────────┘
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 imax‐
abs() 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 ALSOcabs(3), ceil(3), fabs(3), floor(3), rint(3)COLOPHON
This page is part of release 4.14 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 2016-03-15 ABS(3)
