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fabs(3) — Linux manual page

NAME | LIBRARY | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | ATTRIBUTES | STANDARDS | HISTORY | SEE ALSO | COLOPHON 

fabs(3)                 Library Functions Manual                 fabs(3)

NAME         top

       fabs, fabsf, fabsl - absolute value of floating-point number

LIBRARY         top

       Math library (libm, -lm)

SYNOPSIS         top

       #include <math.h>

       double fabs(double x);
       float fabsf(float x);
       long double fabsl(long double x);

   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         top

       These functions return the absolute value of the floating-point
       number x.

RETURN VALUE         top

       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         top

       No errors occur.

ATTRIBUTES         top

       For an explanation of the terms used in this section, see
       attributes(7).
       ┌─────────────────────────────────────┬───────────────┬─────────┐
       │ Interface                           │ Attribute     │ Value   │
       ├─────────────────────────────────────┼───────────────┼─────────┤
       │ fabs(), fabsf(), fabsl()            │ Thread safety │ MT-Safe │
       └─────────────────────────────────────┴───────────────┴─────────┘

STANDARDS         top

       C11, POSIX.1-2008.

HISTORY         top

       C99, POSIX.1-2001.

       The variant returning double also conforms to SVr4, 4.3BSD, C89.

SEE ALSO         top

       abs(3), cabs(3), ceil(3), floor(3), labs(3), rint(3)

COLOPHON         top

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Linux man-pages 6.9.1          2024-05-02                        fabs(3)

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