The Single UNIX ® Specification, Version 2
Copyright © 1997 The Open Group

 NAME

fabs - absolute value function

 SYNOPSIS



#include <math.h>

double fabs(double x);

 DESCRIPTION

The fabs() function computes the absolute value of x, |x|.

An application wishing to check for error situations should set errno to 0 before calling fabs(). If errno is non-zero on return, or the return value is NaN, an error has occurred.

 RETURN VALUE

Upon successful completion, fabs() returns the absolute value of x.

If x is NaN, NaN is returned and errno may be set to [EDOM].

If the result underflows, 0 is returned and errno may be set to [ERANGE].

 ERRORS

The fabs() function may fail if:
[EDOM]
The value of x is NaN.
[ERANGE]
The result underflows.

No other errors will occur.

 EXAMPLES

None.

 APPLICATION USAGE

None.

 FUTURE DIRECTIONS

None.

 SEE ALSO

isnan(), <math.h>.

DERIVATION

Derived from Issue 1 of the SVID.

UNIX ® is a registered Trademark of The Open Group.
Copyright © 1997 The Open Group
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