Bourne shell modifications, past and future (long)

[chris]

> 
> > I think the most glaring difference between csh aliasing and
> > sys5 bourne shell functions is that the latter looks up builtins first.
> > This means you can't define functions that clash with shell commands.
> > On the other hand shell functions have a MUCH better syntax. Why not
> > move up the expansion of shell functions ahead of builtins at
> > the expense of not having recursive functions.
> 
> Very good question.  My guess is that either (a) it was easier
> to do it the other way, or (b) it would be considered a security
> problem in restricted shells.  Can DGK tell us why?

The main implementation problem in having functions overrule builtins is
that both builtins and functions share the same B-tree. If you wanted to
have a function with the same name as a builtin, you would have to save
it somewhere, add new flags, etc... all that adding overhead and
complexity.


Chris
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