You could try using Win32::Fmode or FileHandle::Fmode to determine if the handle passed is open for the appropriate type of operations.

Note: Both will fail to deal with ramfiles or IO::String handles.

In reply to Re: Passing a Filehandle that Might be a Bareword by BrowserUk
in thread Passing a Filehandle that Might be a Bareword by Xiong

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