How to tell which repositories provide which packages?

[Ralf Mardorf]

On Thu, 7 Jan 2021 15:54:40 -0500, Little Girl wrote:
>grep -i "Installed: "

If I would search a text file for "Little Girl" and I'm unsure if it's
"little girl", "LITTLE GIRL" or "Little Girl", then I would use "ignore
case". Here it should match "Installed: ", so I wouldn't ignore the
case.

Regarding the "unique" issue, the issue isn't "sort", the issue is
"unique", since it's no solution to handle false positives. The script
shouldn't suffer from false positives instead of hiding them.

In a later reply I demonstrated that "grep -A4" isn't enough, better
use "grep -A 999999999999999999999999999999999" in case
9999999999999999999 PPAs all provide an installed package named foo and
you want to know from which of those PPAs your foo actually is
installed.

In a nutshell, command line won't do the job. The script needs to
become a file with loops and comparisons, to avoid cheap workarounds.