Re: apt-get remove/purge with regex gives unexpected result

[Richard Hector <richard@walnut.gen.nz>]

On 13/02/14 06:04, Sven Joachim wrote:
> On 2014-02-12 17:25 +0100, rpr nospam wrote:
> 
>> In order to uninstall all libreoffice packages I ran the following
>> apt-get command with a simple regular expression:
>>
>> $ sudo apt-get remove 'libreoffice.*'
>> Reading package lists... Done
>> Building dependency tree
>> Reading state information... Done
>> Note, selecting 'libreoffice.org-calc' for regex 'libreoffice.*'
>> Note, selecting 'libreoffice.org-writer' for regex 'libreoffice.*'
>> Package 'libreoffice.org-calc' is not installed, so not removed
>> Package 'libreoffice.org-writer' is not installed, so not removed
>> 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
>>
>> I'd say this output is unexpected because apt-get does not select
>> installed libreoffice packages listed by dpkg-query.
>>
>> But if the regular expression starts with ^ I get the expected result:
> 
> The apt-get manpage contains the following paragraph:
> 
>   If no package matches the given expression and the expression
>   contains one of '.', '?' or '*' then it is assumed to be a POSIX
>   regular expression, and it is applied to all package names in the
>   database. Any matches are then installed (or removed). Note that
>   matching is done by substring so 'lo.*' matches 'how-lo' and
>   'lowest'. If this is undesired, anchor the regular expression with
>   a '^' or '$' character, or create a more specific regular
>   expression.
> 
> My interpretation of that paragraph is that apt-get first tries to
> interpret the pattern as a wildcard (see glob(7)) and only tries a
> regular expression match if the glob produces no matches.

That would suggest that using the term 'regex' in the output ("Note,
selecting 'libreoffice.org-calc' for regex 'libreoffice.*'") is a bug.

Richard