Name
finite, finitef, finitel, isinf, isinff, isinfl, isnan,
isnanf, isnanl — BSD floating point classification
functions
Synopsis
int
finitel( |
long double |
x) ; |
int
isinfl( |
long double |
x) ; |
int
isnanl( |
long double |
x) ; |
DESCRIPTION
The finite
() functions
return a non-zero value if x
is neither infinite nor a
"not-a-number" (NaN) value, and 0 otherwise.
The isnan
() functions return
a non-zero value if x
is a NaN value, and 0 otherwise.
The isinf
() functions return
1 if x
is plus
infinity, −1 is x
is minus infinity, and 0
otherwise.
NOTE
Note that these functions are obsolete. C99 defines macros
isfinite(), isinf() and isnan() (for all types) replacing
them. Further note that the C99 isinf() has weaker guarantees
on the return value. See fpclassify(3).
AVAILABILITY
On a glibc system, these functions are declared by
<math.h>
when
_BSD_SOURCE or _SVID_SOURCE or _GNU_SOURCE is defined. The
isnan() functions will also be declared when _XOPEN_SOURCE is
defined.
HISTORY
The finite
() function occurs
in 4.3BSD.
SEE ALSO
fpclassify(3), feature_test_macros(7)
Copyright 2004 Andries Brouwer <aeb@cwi.nl>.
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