Shell Programming and Scripting

For example:
<Student>
<Studname>aaa</Studname>
<Studno>123</Studno>
</Student>

 #!/usr/bin/perl

use XML::Simple;

use strict;
use warnings;

my $xml_src=XMLin("data.xml");
my @tags = extract_tags($xml_src);
print "@tags\n";


sub extract_tags{
    my $xml_src=shift;
    my (@tags, %tags);
    for my $key (keys %{$xml_src}){
        $tags{$key}++;
        if (ref($xml_src->{$key}) eq 'HASH'){
            map {$_++;} @tags{extract_tags($xml_src->{$key})}
        }
    }
    push @tags , keys %tags;
    return @tags;
}