LanX mentioned Tie::File recently, and my curiosity made me looked up the source code of that module to see how it works, but I couldn't find what I was looking for. See: https://perldoc.perl.org/Tie::File.txt If someone is trying to read an element of an array, then the file read function is activated. Okay, so it looks like there is a caching mechanism also. But my question is how is this tied to the array though? It looks like the read operation is performed by the _fetch() function, but I could not find that single line of code in the source code that is responsible for intercepting the array read operation and redirecting it to the _fetch() function. An array can also be modified in many ways, and how do we intercept those operations?

Edit: Here is an example what I am trying to achieve: For example, my $CD; I want this to be tied to the current directory, so when I do print $CD; then when it tries to read the scalar value, it first calls _MyGetCWD() function and then prints the value returned by this function. And likewise, if I try to set this variable $CD = "C:\\WINDOWS"; then when it sees that I am trying to modify this scalar, then it immediately calls _MySetCWD($NewValue) function to do the job. How do I do this?

In reply to How to Intercept Variable Access by harangzsolt33

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