And there is yet a third problem with tied scalars. When scalars are passed to a function, e.g. open they are copied (not passed by reference).

Ties do not propagate after a copy, hence the scalar, but neither the tied object nor its associated sub are being passed. The reason you are seeing the correct thing when you print is that when a tied variable is copied, whatever is returned by FETCH is assigned to the variable on the left. Last night I had the similar problem as you when I tried to pass a tied variable to die - which also strips the tied portion from the scalar and throws only the value returned by FETCH

To quote from Programming Perl:

The tie is on the variable, not the value, so the tied nature of a variable does not propagate across assignment. For example, let's say you copy a variable that's been tied:

    $dromedary = $camel;

[download]

Instead of reading the value in the ordinary fashion from the $camel scalar variable, Perl invokes the FETCH method on the associated underlying object. It's as though you'd written this:

    $dromedary = (tied $camel)->FETCH():

[download]

Best, beth

In reply to Re: Using a tied scalar as an in memory file by ELISHEVA
in thread Using a tied scalar as an in memory file by duncs

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