fabs, fabsf, fabsl - absolute value of floating-point number
#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
These functions return the absolute value of the floating-point number
x.
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.
No errors occur.
For an explanation of the terms used in this section, see
attributes(7).
| Interface |
Attribute |
Value |
| fabs (), fabsf (), fabsl () |
Thread safety |
MT-Safe |
C99, POSIX.1-2001, POSIX.1-2008.
The variant returning
double also conforms to SVr4, 4.3BSD, C89.
abs(3),
cabs(3),
ceil(3),
floor(3),
labs(3),
rint(3)