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);
Feature Test Macro Requirements for glibc (see
feature_test_macros(7)):
llabs():
_ISOC99_SOURCE ||
_POSIX_C_SOURCE >= 200112L
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.
cabs(3),
ceil(3),
fabs(3),
floor(3),
rint(3)