$($This needs to be coded in a bash script$)$

Step $2-$ Unzip the file quietly

Unzip the file that was given as the first argument. Use the option that suppresses the output. I don't want to see it all.

If the zip file cannot be unzipped $($an invalid zip file$),$ then I want you to print an error message to STDERR and stop

the script.

The error message must contain the work "ERROR"

Step $3-$ Change the names of the directories

I want all the student directories names changed to just the student numbers.

Step $4-$ Copy student answers to current directory & rename I want all the student files $(*.$txt $)$ copied to the current directory, with the student number followed by an underscore pre$-$pended to the filename

I don't really get how to do this, especially step $4.$ Any help would be appreciated.