searching through a string?

if i wanted to search through a string with the input of the user, how would i do that?

i.e.
user input for search: a
subjects:
alberto
randels
zardoz
printer

the search would return alberto, randels, & zardoz all because they contain the letter a, but not printer because it doesn't.

how would i do this?

thanks alot


------------------
rrandels.

#!/usr/local/bin/perl

print "Enter somethingn";
chomp($input = <STDIN> );

if ($input =~ /a/){
print "has an 'a'";
}
else{
print "no 'a' here";
}