I have a huge XML file to parse. I was thinking that instead of parsing the whole file, I could ask the user to input a few options and then parse only that portion of the file. I was basically planning to do this 
Enter option to be parsed
1. Fiction
2. History
3. Religion


10. Non fiction

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So once the user enters the number 2, Book 2 will get selected and bunch of other options will be displayed as follows 

Selected Book 2. Options are as follow
1. World History
2. American History
3. Oriental History


10. Indian History

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Each option is nested differently with different levels. The plan is to use a switch statement on the returned $_ to display options for the next level. How do I navigate to a different part of the program and display options according to the genre selected. Thanks! 

use strict;
use warnings;
use Switch;
my $level1;
print "Select options: \n 1 Fiction \n 2 History \n 3 Religion \n";
my $no = getIP('Enter a digit : ', /^\d/);
switch ($no) {
        case 1        { $level1 = ?? }
        case 2        { $level1 = ?? }
                case 3        { $level1 = ?? }
        else        { $level1= ?? }
        
}
print $level1;


sub getIP {
    print $_[0];
    do {
        $_ = <STDIN>; chomp;
    } while ($_[1] && $_ !~ $_[1]);
    return $_;
}

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In reply to Best way to handle interactive user input? by Ppeoc

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