I ran into this problem in the past when trying to allow a function to accept filenames or filehandles.

From my testing at the time I don't think it is possible to determine if a scalar is a filehandle or not. As you point out the IO:: objects would be difficult to handle.

The solution that I can up with was just to assume that any references passed to the function were filehandles and any scalars were filenames. Here is an extract from the code. 

    # If the filename is a reference it is assumed that it is a valid
    # filehandle, if not we create a filehandle.
    #
    if (ref($OLEfile)) {
        $fh = $OLEfile;
    }
    else {
        # Create a new file, open for writing
        $fh = FileHandle->new("> $OLEfile");
        if (not defined $fh) {
            croak "Can't open $OLEfile. ......";
        }

        # binmode file whether platform requires it or not
        binmode($fh);

    }

    # Store the filehandle
    $self->{_filehandle} = $fh;

[download]
This isn't bullet-proof but if the documentation is explicit then it may be sufficient.

--
John.

In reply to Re: Re: Re: File::Grep by jmcnamara
in thread File::Grep by Masem

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