You can invoke GNOME Disk Catalog from command line by typing
$ diskcatalog &
GNOME Disk Catalog gives every file three attributes: name, path and disk. The name is the filename without path. The path is found from path attribute :) and disk is given by user.
The data is saved to user selected file and it can be read from there at startup (or with open command).
GNOME Disk Catalog has a little command line, just below toolbar. User (you) can give commands like list all to it.
Complete command summary is following:
count
list <file>
list all
search all
search file <name>
view disk <diskname>
view disks
open <filename>
clear
<name>
delete <name> <path> <disk>
describe <name> <path> <disk> <description>
Of course you should be able to delete entries from catalog. So delete does it for you. You must specify which entry must be deleted by giving to the command delete three arguments: name, path and disk. Again regural expressions can be used.
The describe command adds given description to specified file(s) and count counts database entries.
The menu bar is located at the top of the window by default. The place can be changed, but that is covered in the global GNOME documentation.
The menu bar has three menus, File, Actions and Help. From File and Actions menus you can create new/open/save catalog, add/search files to/from catalog and edit preferences.
Same functions can be found from toolbar too, so toolbar isn't covered here (yet).
The GNOME Disk Catalog has three options.
Update list after each command
Use new style catalog format
Open catalog at startup