FPCLASSIFY(3) BSD Library Functions Manual FPCLASSIFY(3)

NAME
     ffppccllaassssiiffyy, iissffiinniittee, iissiinnff, iissnnaann, iissnnoorrmmaall - classify a floating-point
     number

LLIIBBRRAARRYY
     Math Library (libm, -lm)

SYNOPSIS
     ##iinncclluuddee <>

     int
     ffppccllaassssiiffyy(real-floating x);

     int
     iissffiinniittee(real-floating x);

     int
     iissiinnff(real-floating x);

     int
     iissnnaann(real-floating x);

     int
     iissnnoorrmmaall(real-floating x);

DESCRIPTION
     The ffppccllaassssiiffyy() macro takes an argument of x and returns one of the fol-
     lowing manifest constants.

     FPINFINITE   Indicates that x is an infinite number.

     FPNAN        Indicates that x is not a number (NaN).

     FPNORMAL     Indicates that x is a normalized number.

     FPSUBNORMAL  Indicates that x is a denormalized number.

     FPZERO       Indicates that x is zero (0 or -0).

     The iissffiinniittee() macro returns a non-zero value if and only if its argument
     has a finite (zero, subnormal, or normal) value.  The iissiinnff(), iissnnaann(),
     and iissnnoorrmmaall() macros return non-zero if and only if x is an infinity,
     NaN, or a non-zero normalized number, respectively.

SEE ALSO
     isgreater(3), math(3), signbit(3)

STANDARDS     The ffppccllaassssiiffyy(), iissffiinniittee(), iissiinnff(), iissnnaann(), and iissnnoorrmmaall() macros
     conform to ISO/IEC 9899:1999 (``ISO C99'').

HISTORY     3BSD introduced iissiinnff() and iissnnaann() functions, which accepted double
     arguments; these have been superseded by the macros described above.

BSD                              July 8, 2004                              BSD