Re: "GROUPS" is read-only, but only sort of

[Jonathan Kamens]

>  Date: Fri, 3 Nov 2000 13:04:07 -0500
>  From: Chet Ramey <chet@nike.ins.cwru.edu>
>  
>  The current behavior is documented.

The fact that something is documented doesn't make it OK.

This makes bash incompatible with every other Bourne-compatible
shell.  In fact, it makes bash a Bourne-*in*compatible shell.  Scripts
which are written to use only standard sh constructs can fail
silently, with no obvious explanation, under bash, just for using a
variable named GROUPS.

>  GROUPS was originally readonly.  People complained that they could not even
>  unset it (since readonly variables can't be unset), and that screwed up
>  their scripts.  I received multiple complaints about the oracle install
>  script, for one.
>  
>  The current behavior is a compromise.  GROUPS is essentially readonly,
>  but may be unset.

But all of those scripts will continue to break, but in a completely
different way!  How can an installation script know that before it's
allowed to set a variable named GROUPS, it has to unset it?

At least if attempting to reset GROUPS caused a visbible error, people
writing or maintaining such scripts would know immediately what the
problem is.  I fail to see how the current behavior can be preferable
to that.

  jik