How can I list all packages I've installed from a particular repository?

How can I list all packages I've installed from a particular repository?

How can I list all installed packages that are not available from the main Ubuntu archives, and also see which repositories they came from? (If I knew the answer to this question, I could grep that list for a particular PPA name to find out the answer to my first question.)

There seems to be no record of the origin of an installed package.

If you are fine with getting the location from whence a package of the same name would be downloaded from, this is available through apt-cache policy. The following (rather ugly) script does the trick for me:

LC_ALL=C dpkg-query --showformat='${Package}:${Status}\n' -W '*' \
  | fgrep ':install ok installed' \
  | cut -d: -f1 \
  | (while read pkg; do 
       inst_version=$(apt-cache policy $pkg \
                                | fgrep Installed: \
                                | awk '{ print $2 }'); 
       origin=$(apt-cache policy "$pkg" \
                          | fgrep " *** ${inst_version}" -C1 \
                          | tail -n 1 \
                          | cut -c12-); 
       echo $pkg $origin; 
     done)

Note that it's quite fragile, as it makes assumptions about the output of apt-cache policy, which might change across versions...

Expand the "Installed Software" item in Ubuntu Software Center. You'll see a list of all the different repositories that you've enabled. Clicking on the repo will show you the packages you've installed from each.

Open Synaptic Package Manager and click the "Origin" button on the bottom of the left sidebar. It will list your sources. Select a source to see the available/installed packages.

This script lists packages that are installed and available in the PPA:

#!/bin/sh
# Give PPA name as an argument, e.g. ppa:oibaf/graphics-drivers

name1="$(echo "$1"|cut -d: -f2|cut -d/ -f1)"
name2="$(echo "$1"|cut -d/ -f2)"

awk '$1 == "Package:" { if (a[$2]++ == 0) print $2; }' \
/var/lib/apt/lists/*"$name1"*"$name2"*Packages |
xargs dpkg-query -W -f='${Status} ${Package}\n' 2>/dev/null  | awk '/^[^ ]+ ok installed/{print $4}'

I applied this.

BTW, as for removing PPA from use, use ppa-purge program; I have created an improved version of it here.