ISINF
NAME SYNOPSIS DESCRIPTION CONFORMING TO
isinf, isnan, finite - test for infinity or not-a-number (NaN)
#include value); int isnan(double value); int finite(double value);
The isinf() function returns -1 if value represents negative infinity, 1 if value represents positive infinity, and 0 otherwise.
The isnan() function returns a non-zero value if value is ''
The finite() function returns a non-zero value if value is neither infinite nor a ''
BSD 4.3
