abs, labs, llabs, imaxabs - compute the absolute value of an integer
Standard C library (
libc,
-lc)
#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);
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.
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.
cabs(3),
ceil(3),
fabs(3),
floor(3),
rint(3)