1 .\" Copyright 2004 Andries Brouwer <aeb@cwi.nl>.
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23 .TH FINITE 3 2004-10-31 "" "Linux Programmer's Manual"
25 finite, finitef, finitel, isinf, isinff, isinfl, isnan, isnanf, isnanl \-
26 BSD floating point classification functions
33 .BI "int finite(double " x );
35 .BI "int finitef(float " x );
37 .BI "int finitel(long double " x );
39 .BI "int isinf(double " x );
41 .BI "int isinff(float " x );
43 .BI "int isinfl(long double " x );
45 .BI "int isnan(double " x );
47 .BI "int isnanf(float " x );
49 .BI "int isnanl(long double " x );
54 functions return a non-zero value if \fIx\fP is neither infinite
55 nor a "not-a-number" (NaN) value, and 0 otherwise.
59 functions return a non-zero value if \fIx\fP is a NaN value,
64 functions return 1 if \fIx\fP is plus infinity, \-1 is \fIx\fP
65 is minus infinity, and 0 otherwise.
68 Note that these functions are obsolete. C99 defines macros
69 isfinite(), isinf() and isnan() (for all types) replacing them.
70 Further note that the C99 isinf() has weaker guarantees on the return value.
74 .\" finite* not on HP-UX; they exist on Tru64.
76 On a glibc system, these functions are declared by
78 when _BSD_SOURCE or _SVID_SOURCE or _GNU_SOURCE is defined.
79 The isnan() functions will also be declared when _XOPEN_SOURCE
84 function occurs in 4.3BSD.
85 .\" see IEEE.3 in the 4.3BSD manual
88 .BR feature_test_macros (7)