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/.