On 8/9/21 5:35 PM, Franklin, Jason wrote:
> Greetings:
>
> I discovered today that the GROUPS variable is special in Bash.
It is. For everyone else:
GROUPS An array variable containing the list of groups of which the
current user is a member. Assignments to GROUPS have no effect.
If GROUPS is unset, it loses its special properties, even if it
is subsequently reset.
>
> I moved some scripts to a new box, and they stopped working. On this
> box, /bin/sh linked to /bin/bash instead instead of /bin/dash.
>
> Scripts of of this form...
>
> #!/bin/sh
> GROUPS='foo bar'
> # do something with $GROUPS here
>
> had worked because GROUPS had no special meaning under /bin/dash.
>
> The script is invoked with /bin/sh (linked to /bin/bash), so I had
> expected Bash POSIX compliance to take over. It did not.
POSIX, which does not specify GROUPS, does not make a difference.
If you would like this to work on dash and bash, unset GROUPS before
trying to assign to it.
> Is this considered a bug?
It's not.
> Should bash, invoked with "--posix" or as "sh", omit the special
> treatment of variables such as GROUPS?
No. Bash does not try to restrict itself to only those things specified
by POSIX.
--
``The lyf so short, the craft so long to lerne.'' - Chaucer
``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU c...@case.edu http://tiswww.cwru.edu/~chet/
