double
     logb(double x);

     long double
     logbl(long double x);

     float
     logbf(float x);

DESCRIPTION

     The logb() functions return the exponent of x, represented as a floating-
     point number.

SPECIAL VALUES

     logb(+-0) returns -infinity and raises the "divide-by-zero" floating-
     point exception.

     logb(+-infinity) returns +infinity.

SEE ALSO

     ilogb(3)

STANDARDS

     The logb() functions conform to ISO/IEC 9899:1999(E).

BSD                              July 24, 2003                             BSD