cannot declare local variables if they're readonly

[isabella parakiss]

>From variables.c

                                       The test against old_var's context
     level is to disallow local copies of readonly global variables (since I
     believe that this could be a security hole).

Can you please explain how that can be a security hole?


$ readonly wtf; fn () { local wtf; }; fn
bash: local: wtf: readonly variable

You can't even be sure that you can set *local* variables in a function.
This is a problem.


Most of the shells that support local variables (ksh93, mksh, zsh, dash...)
allow this.  The only one I could find that doesn't is busybox.


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xoxo iza