"apt-mark showmanual" will show you all packages that you have manually installed
"apt-mark showauto" will show you all packages that are automatically installed
"apt-mark showinstall" will show you all the packages that are installed
How is this useful? It tells you what packages are installed in your system.
So you can go "apt-mark showinstall | grep somelibrary" to see if you have a particular library installed that's a dependency.
Vintage Apple IIe 2e iie Personal Computer A2S2064 V1718 *TESTED AND WORKING*
$175.00
Rare Vintage Apple Macintosh Powerbook 160 9.8" Screen Laptop - UNTESTED
$54.99
Vintage Apple A2M2010 Monitor II, Green Phosper CRT
$99.99
Vintage Apple Power Macintosh 5400/120 M3046 Computer Display Arcs Tested Boots
$169.95
Apple Computer Vintage sheet of 1990s rainbow logo stickers 2 Sticker Sheet
$4.80
Vintage Classic Apple Macintosh System Boot Install Disk Floppy/CD *Pick Version
$10.39
Vintage Rare Apple IIc Plus A2S4500 Turns On, Physical Condition Is Good.
$425.00
Vintage Apple Logo Calculator. New in original box. LAST ONE...................
$25.75
Vintage Apple IIe Computer A2S2128 (825-1351-A)
$174.99
Vintage Apple Macintosh 512K / Mouse, Keyboard & Extras + Carry Case / Turns On
$260.00