FABS
Section: Linux Programmer's Manual (3)
Updated: 2008-08-05
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NAME
fabs, fabsf, fabsl - absolute value of floating-point number
SYNOPSIS
#include <math.h>
double fabs(double x);
float fabsf(float x);
long double fabsl(long double x);
Link with -lm.
Feature Test Macro Requirements for glibc (see
feature_test_macros(7)):
fabsf(),
fabsl():
_BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE; or
cc -std=c99
DESCRIPTION
The
fabs()
functions return the absolute value of the floating-point
number x.
RETURN VALUE
These functions return the absolute value of
x.
If
x
is a NaN, a NaN is returned.
If
x
is -0, +0 is returned.
If
x
is negative infinity or positive infinity, positive infinity is returned.
ERRORS
No errors occur.
CONFORMING TO
C99, POSIX.1-2001.
The variant returning
double
also conforms to
SVr4, 4.3BSD, C89.
SEE ALSO
abs(3),
cabs(3),
ceil(3),
floor(3),
labs(3),
rint(3)
COLOPHON
This page is part of release 3.22 of the Linux
man-pages
project.
A description of the project,
and information about reporting bugs,
can be found at
http://www.kernel.org/doc/man-pages/.