Using Perl:

Write a subroutine named greet that welcomes the person you name by telling each new person the names of all the people it has previously greeted:

greet( "Fred" );

greet( "Barney" );

greet( "Wilma" );

greet( "Betty" );

This sequence of statements should print:

Hi Fred! You are the first one here!

Hi Barney! I've seen: Fred

Hi Wilma! I've seen: Fred Barney

Hi Betty! I've seen: Fred Barney Wilma