| .\" Copyright 2004 Andries Brouwer <aeb@cwi.nl>. |
| .\" |
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| .TH FINITE 3 2004-10-31 "" "Linux Programmer's Manual" |
| .SH NAME |
| finite, finitef, finitel, isinf, isinff, isinfl, isnan, isnanf, isnanl \- |
| BSD floating point classification functions |
| .SH SYNOPSIS |
| .nf |
| #define _BSD_SOURCE |
| .br |
| .B #include <math.h> |
| .sp |
| .BI "int finite(double " x ); |
| .br |
| .BI "int finitef(float " x ); |
| .br |
| .BI "int finitel(long double " x ); |
| .sp |
| .BI "int isinf(double " x ); |
| .br |
| .BI "int isinff(float " x ); |
| .br |
| .BI "int isinfl(long double " x ); |
| .sp |
| .BI "int isnan(double " x ); |
| .br |
| .BI "int isnanf(float " x ); |
| .br |
| .BI "int isnanl(long double " x ); |
| .fi |
| .SH DESCRIPTION |
| The |
| .BR finite () |
| functions return a non-zero value if \fIx\fP is neither infinite |
| nor a "not-a-number" (NaN) value, and 0 otherwise. |
| |
| The |
| .BR isnan () |
| functions return a non-zero value if \fIx\fP is a NaN value, |
| and 0 otherwise. |
| |
| The |
| .BR isinf () |
| functions return 1 if \fIx\fP is plus infinity, \-1 is \fIx\fP |
| is minus infinity, and 0 otherwise. |
| |
| .SH 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 |
| .BR fpclassify (3). |
| .\" |
| .\" finite* not on HP-UX; they exist on Tru64. |
| .SH AVAILABILITY |
| On a glibc system, these functions are declared by |
| .I <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. |
| .SH HISTORY |
| The |
| .BR finite () |
| function occurs in 4.3BSD. |
| .\" see IEEE.3 in the 4.3BSD manual |
| .SH "SEE ALSO" |
| .BR fpclassify (3) |