NAME    [Toc]    [Back]

     isinf, isnan - test for infinity or not-a-number

LIBRARY    [Toc]    [Back]

     Standard C Library (libc, -lc)

SYNOPSIS    [Toc]    [Back]

     #include <math.h>

     int
     isinf(double);

     int
     isnan(double);

DESCRIPTION    [Toc]    [Back]

     The isinf() function returns 1 if the number is ``infinity'', otherwise
     0.

     The isnan() function returns 1 if the number is ``not-a-number'', otherwise
 0.

SEE ALSO    [Toc]    [Back]

     isinff(3), isnanf(3), math(3)

     IEEE Standard for Binary Floating-Point Arithmetic, Std 754-1985, ANSI.

BUGS    [Toc]    [Back]

     Neither the VAX nor the Tahoe floating point have distinguished values
     for either infinity or not-a-number.  These routines always return 0 on
     those architectures.

BSD                            January 29, 1994                            BSD