How to check that if a package is installed?

[Boggess Rod]

Date: Tue, 30 Nov 2010 09:15:15 -0500
From: Hal Burgiss <hal at burgiss.net>
Subject: Re: How to check that if a package is installed?
To: "Ubuntu user technical support,	not for general discussions"
	<ubuntu-users at lists.ubuntu.com>
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	<AANLkTi=Yy4OcXjto+n=s0hfZYO1Z+=xFPP96mgpUfyUN at mail.gmail.com>
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On Tue, Nov 30, 2010 at 7:54 AM, S Mathias <smathias1972 at yahoo.com>
wrote:

> if [ "$(dpkg -l | awk '/tofrodos/ && /^ii/ {print $2}' | awk
> '/^tofrodos/')" == "" ]; then echo -e "error: no zip package
> detected\!\n\nYou could install it like e.g.: \"apt-get install
tofrodos\"";
> fi
>
> Is there a better way then this?
>
>
Seems kind of wordy to me for what it really does ...

dpkg -l |grep torfrodos || echo nope


-- 

I wasn't following this thread from the beginning, but is there a reason
we're avoiding the GUI? Why not just look at the installed packages in
synaptic package manager or whatever they replaced it with in the newest
release?