**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 3.24 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/.
2008-08-05 FABS(3)