Manpages - fabs.3

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 <= 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).

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)

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