How can I have two pset4's ; one from 2018 and one from 2019?

Question

I had completed up to and including pset4 in 2018, and upon resuming in 2019 I was required to resume with the new pset4. How can I have 2 pset4's in the same workspace? For now, I named the 2019 pset "pset42019".

In the understanding section of pset4 in 2019, I am asked to implement the staff's solution :

~cs50/pset4/speller texts/lalaland.txt    

I tried that and also tried something similar by typing "pset42019" instead of "pset4", and both do not work. (the "pset42019" not working kind of makes sense, but why isn't "pset4" working?) Here is what I have in my terminal:

~/workspace/ $ ~cs50/pset42019/speller texts/lalaland.txt
bash: /home/cs50/pset42019/speller: No such file or directory
~/workspace/ $ ~cs50/pset4/speller texts/lalaland.txt
Could not open texts/lalaland.txt.
~/workspace/ $ cd ~/workspace/pset42019/
~/workspace/pset42019/ $ ~cs50/pset4/speller texts/lalaland.txt
Could not open texts/lalaland.txt.
~/workspace/pset42019/ $ ~cs50/pset42019/speller texts/lalaland.txt
bash: /home/cs50/pset42019/speller: No such file or directory
~/workspace/pset42019/ $ cd ~/workspace/
~/workspace/ $ ~cs50/pset4/speller texts/lalaland.txt
Could not open texts/lalaland.txt.
~/workspace/ $ 

How do I get this to work? Thank you

Answer 1

If you followed the downloading instructions, you would have a speller directory in either (or both) pset4 / pset42019. You would run the executables from there. cd speller should do the trick.

Answer 2

The staff command is assuming that you are running it in your pset4 directory (or whatever you've named it) where you have the texts subfolder. So try running it there

~/workspace/pset42019/ $ ~cs50/pset4/speller texts/lalaland.txt