A bash script to check whether a string satisfies the requirements for a username.
This repo contains a zip.sh bash script that checks whether a string is a valid 5 digit zip code. It is to be used as the starting point for a script to check whether a string satisfies the requirements for a username.
The requirements for a username are:
- The only characters that can be used are
- lower case letters,
 - digits, and
 - the underscore character
 
 - It must start with a lower case letter
 - It must contain at least three but no more than 12 characters
 
Copy the zip.sh file to a file named username.sh Edit the username.sh file so that it:
- Contains your name as the author
 - Contains the correct name of the file
 - Displays the rules to the user
 - Prompts to user to type a username
 - Checks to see if the string typed by the user obeys the rules.
 - Prompts the user to try again if it does not.