dpkg wildcards

UNIX for Advanced & Expert Users
1

Are there different rules with wildcards in dpkg? I was looking at this.
Getting information about packages

%  dpkg -l \*apt\* 
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Installed/Config-files/Unpacked/Failed-config/Half-installed
|/ Err?=(none)/Hold/Reinst-required/X=both-problems (Status,Err: uppercase=bad)
||/ Name              Version           Description
+++-=================-=================-=============================================================
ii  apt               0.3.19            Advanced front-end for dpkg
ii  apt-move          3.0-13            Move cache of Debian packages into a mirror hierarchy
ii  aptitude          0.0.4a-4.1        Console based apt frontend
un  libapt-pkg-dev    <none>            (no description available)
un  libapt-pkg-doc    <none>            (no description available)
un  libapt-pkg2.7     <none>            (no description available)
pn  task-laptop       <none>            (no description available)

I thought with the it used this command that it would treat the "" as a literal "" and not a wildcard. I thought the "\" takes away special meanings. Could anyone explain why this is happening? I put that command in terminal with and without the "\" and I got the same thing both times. I would think with the way it is put that it would look for "*apt*".

dpkg -l \*apt\*
2

You can use

dpkg -l *apt*

which will work except when there happen to be files with the pattern *apt* in your current directory, after which the shell will replace the pattern with file names which is not what you want. If they are not there the pattern is passed unchanged.

In order to not leave things to chance it is better to use

dpkg -l \*apt\*

or

dpkg -l '*apt*'