What does ./!$ mean in Linux?
Question: A noobie Linux learner here.

I created a python script and `chmod 700 filename.py`, when I was going to
using `./filename.py`, my instructor came and use `./!$` to run the file.

What does the `./!$` that actually mean? I couldn't google it out. I'd greatly
appreciate for a link of cheatsheet for the similar commend too.

Thanks in advance.


Answer: Suppose I just ran a command `python test.py`. This was my last command I
entered into the shell. However, its argument was `test.py`.

Remembering that `./` refers to the current working directory, when I type
`./!$` I get the following output:

    
    
    $ ./!$
    ./test.py
    ./test.py: line 1: import: command not found
    ./test.py: line 2: $'\r': command not found
    ./test.py: line 3: syntax error near unexpected token `('
    '/test.py: line 3: `df = pd.DataFrame([
    

By context clues my last argument was used as the `!$`.

If I enter several arguments such as `python test.py test2.py` I get:

    
    
    $ ./!$
    ./test2.py
    ./test2.py: line 1: import: command not found
    Unable to initialize device PRN
    

Confirming my intuition.

