How to check if eval() changes values of any local variables?
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Dear all,
I have a GUI that lets users to evaluate custom scripts, mostly problem oriented functions. The scripts for running need to create some temporary variables and I would like to make sure that they don’t mess up the local workspace. Is there any clean and neat way to do?
Thank you for your help, Kirill Andreev
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Answers (3)
Walter Roberson
on 16 Jan 2012
No, it is always possible to escape from eval() and do arbitrary things. What-ever mechanisms MathWorks uses for the Contents are not available to users.
If you want security, do not use eval() on user input without having proven the input to be harmless (which is generally a tough task.)
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Sean de Wolski
on 16 Jan 2012
Package their script into a function (using fopen/fwrite/fprintf so that it uses its own local workspace. Call the function.
Waallaa! No eval and no poofing
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Sean de Wolski
on 16 Jan 2012
Rather than saving them to disk you could set them to appdata, which will be MUCH faster:
doc setappdata/doc getappdata
Jan
on 16 Jan 2012
You can shadow assignin by creating an own function with the same name. Then you can catch the 'base' and 'caller' argument and collect all changes separately from the actual workspace.
As long as the users can call eval, strange this will happen - promissed! Somebody will create a variable called 'load' and you will not be able to load the variable dump any longer.
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