FABS(3)                                                                 Linux Programmer's Manual                                                                FABS(3)

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():
           _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
               || /* Since glibc 2.19: */ _DEFAULT_SOURCE
               || /* Glibc <= 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
       abs(3), cabs(3), ceil(3), floor(3), labs(3), rint(3)

                                                                               2021-03-22                                                                        FABS(3)