Name
abs, labs, llabs, imaxabs — compute the absolute
value of an integer
Synopsis
long
int labs( |
long int |
j); |
long
long int llabs( |
long long int |
j); |
#include <inttypes.h>
intmax_t imaxabs( |
intmax_t |
j); |
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 function.
RETURN VALUE
Returns the absolute value of the integer argument, of the
appropriate integer type for the function.
CONFORMING TO
SVr4, POSIX.1-2001, 4.3BSD, C99. 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, but is not in libc5 or
libc4. 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.
GCC handles abs() and
labs() as builtin functions.
GCC 3.0 also handles llabs()
and imaxabs() as builtins.
SEE ALSO
cabs(3), ceil(3), fabs(3), floor(3), rint(3)
Copyright 1993 David Metcalfe (david@prism.demon.co.uk)
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Formatted or processed versions of this manual, if unaccompanied by
the source, must acknowledge the copyright and authors of this work.
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 (faith@cs.unc.edu)
Modified Sat Dec 16 15:02:59 2000, Joseph S. Myers
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