[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: Proposed new POSIX sh policy

On Sat, Nov 11, 2006 at 11:10:52PM -0600, Manoj Srivastava wrote:

>         It would, at one fell swoop, solve the problem Thomas hinted
>  at before, about our specification allowing shell to randomly shadow
>  other commands on the system.

(I missed this part in my previous mail)

Using /bin/bash does _NOT_ solve this problem as bash allows you to
dynamically enable, disable and re-define the built-in commands. Even
worse, bash allows you to load a DSO and use it as a built-in command.
Just imagine if some maintainer scripts start to supersede ls, sed,
awk etc. this way...

And if you want do disallow the problematic features, then policy
quickly becomes much more complex than just saying "all maintainer
scripts must also work with dash".

So again I propose that instead of listing features, policy should just
say "maintainer scripts must work with bash, dash [and probably a 3rd
alternative]". And if someone wants to use a shell not on this list as
/bin/sh, then he is on his own and if something breaks then that's at
most a wishlist bug.


     MTA SZTAKI Computer and Automation Research Institute
                Hungarian Academy of Sciences

Reply to: