ferror - returns whether there is an error condition on a file
file.ferror()
The error indicator for a File may be tested
with the ferror() intrinsic method. The error
indicator can be cleared with the clearerr()
intrinsic method.
An Int corresponding to the underlying runtime
implementation of the file error indicator. A zero value indicates no
error indicator has been set.
ArgCheck if arguments are specified
TypeCheck if file is not a
File
AccessCheck if
file is closed
if (file.ferror()) {
file.clearerr();
}