#!/usr/bin/perl
use warnings;
use strict;
use Glib;
use Glib qw/TRUE FALSE/;

use Term::ReadKey;
$|++;
ReadMode('cbreak');

my $main_loop = Glib::MainLoop->new;

Glib::Idle->add(
        sub{
            my $char;
            if (defined ($char = ReadKey(0)) ) {
            print "$char->", ord($char),"\n";    
            #process key presses here
            }
          return TRUE; #keep this going
          });
       
$main_loop->run;
ReadMode('normal'); # restore normal tty settings
__END__
[download]

#!/usr/bin/perl
use warnings;
use strict;
use Term::ReadKey;
$|=1;

ReadMode('cbreak');

my $key = '';
 while ( $key ne 'q' ) {
     while (not defined ($key = ReadKey(-1))) {
         # No key yet
      }
    print "Get key '$key'\n";
    print ord($key);
    print "\n";
 }


__END__

while(1){
my $char;
if (defined ($char = ReadKey(0)) ) {
        print "$char->", ord($char),"\n";    # input was waiting and i
+t was $char
} else {
          # no input was waiting
        }
}

ReadMode('normal');                  # restore normal tty settings
[download]

To clarify, this menu is all text-based. None of it is windowed.

To further clarify, user input is not a condition, just an example.

Don't know if this will fit your needs but you might consider an until statement like the following:

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
}
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Gleaned from Chapter 13, Beginning Perl, page 441.