Something fulfilling what you believe would work best
One way to create "shortcuts" for pathnames would be to define environment variables:
export folder1234='folder1/folder2/folder3/folder4'
export short_filename='my_super_very_long_amazing_filename.txt'
This way, you could reduce your typing to
ls $folder1234
cat $folder1234/$short_filename
While that sounds like a magnificent idea, nobody appears to do that. It indeed requires you to set up and maintain static definitions, and remember all of these artifacts. These will work the period you work on a project, but will be largely obsolete once you move to a different project.
The better workflow using standard tools
The better way to avoid long path names, is to turn into a habbit of changing to the directory where you need to do your work. This way, it takes a single
cd folder1/folder2/folder3/folder4/
(where you use autocompletion and tab) to bring you there. Next day, you will get there more quickly: instead of attempting the command again, type Ctrl+r: this starts a reverse search through your history. Type folder4 and you will quickly see your cd command again. Select it and execute it. Done.
Once inside that folder, typing the long filename is a no-brainer using the tab autocompletion.
On steroids
Install fuzzy finder. sudo apt install fzf
At the empty prompt, hit Alt+c. Fuzzy finder will pop up. Type folder4: you will see the full folder name, select it, hit enter and you are there.
Type cat then Ctrl+t. my_super_very may already reveal your file only. Hit enter to add the full path to the command line.
Alternative to the above: type ** then Tab to trigger fussy finder.
