use strict;
use warnings;

$_ = "";
until (/^q/i) {

print "What to do: ('o' for options)\n";
chomp ($_ = <STDIN>);

if ($_ eq "o") { dboptions() }
elsif {$_ eq "r" { readdb() }
elsif .....
.....
else {print "Sorry, try again.\n";}
}

sub dboptions {
  print <<EOF;
  Your options are:
  o - view options
  r - read
  ....
  ....
EOF
}