A simple bash script would be easy enough to do.
Hopefully this isn't homework, although this is probably too easy for homework, sooo
Code:
#!/bin/bash
ls /path/to/your/directory
read -p "Which file do you want to open? :" this_file
nano /path/to/your/directory/${this_file}
exit 0
ls /path/to/your/directory -- this line lists your directory of files
read -p "Which file do you want to open? :" this_file -- this line allow you to choose your file
nano /path/to/your/directory/${this_file} -- this line opens the file in nano, you could of course change this to vi,emacs, whatever floats your boat.
