Question

I have used the example from http://www.regular-expressions.info/examples.html to validate the following code

while [[ ! $name =~ ^[a-Z][ \t][a-Z]. ]]; do

                echo "Please enter your Firstname and Surname e.g Joe Bloggs"                           # (a)Ask for NAME,TELEPHONE NUMBER,DOB #
                read name
                echo
        done

I am quite simply looking to ensure user enters first and second name with a space any help would be greatly appreciated!

Answer 1

There are several problems with your regex:

• You’re checking for characters between a (lowercase) and Z (uppercase). This won’t do what you expect, use [A-Za-z] to check both upper and lowercase letters.
• You’re missing repeat characters; use + to match one or more characters.
• The end-of-match should be $, not . (which matches any single character).

Try this:

^[A-Za-z]+[\ \t][A-Za-z]+$

If you want to validate Uppercased first and last names you could use:

^[A-Z][a-z]+[\ \t][A-Z][a-z]+$

But this would not work with names like Marty McFly that don’t follow that rule.