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():
_ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
|| /* Since glibc 2.19: */ _DEFAULT_SOURCE
|| /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
Description
These 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.
Attributes
For an explanation of the terms used in this section, see attributes(7).
| Interface | Attribute | Value |
|---|---|---|
| fabs(), fabsf(), fabsl() | Thread safety | MT-Safe |
Conforming to
C99, POSIX.1-2001, POSIX.1-2008.
The variant returning double also conforms to SVr4, 4.3BSD, C89.
See Also
Colophon
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Referenced By
The man pages fabsf(3) and fabsl(3) are aliases of fabs(3).