I really appreciate your sole quest to master *nix and associates challenges, and I'd like to support you with it. Let's start with a few comments:
Don't intermix the various topics / fields, which you do in your first post, mixing shell and awk syntax. Concentrate on one only first, then extent your work to others. Don't work with non-*nix tools (windows(?) editors) so not to introduce off-system errors (e.g. locale double quotes) leading to syntax problems.
Let's start with some comments on your last post:

Code:

input=“AfileinDir”

Syntax error! The double quotes are NOT the required ASCII " (oct 042, dec 34, hex 22). What editor do you use? Change to a genuine *nix one, or at least switch yours to *nix mode. While we're at it, make sure your script lines are terminated correctly (\n in *nix, NO \r!)

Code:

if [ $input == echo$(ls) ];  # or if [ $input == $(ls) ]

bash: [: too many arguments: echo$(ls) evaluates to like "echofile1 file2 etc", i.e. the string "echo" immediately followed by the list of files in your directory. Will rarely fit anything in your $input variable. Would ls $input do what you want (check if file exists in current working dir)?


Don Cragun already pointed out many aspects of the failure of your approach. I just want to emphasize that without a basic understanding of the operation of both shell and awk and the sometimes subtle differences between the two, and, no less important, the ways and methods they interact, it will become difficult to compose a working solution.