help in parsing - perl

Question

I am having a XML file as shown below,
<message1>
<val1>100</val1>
<val2>200</val2>
<val3>300</val3>
<val4>400</val4>
</message1>
<message2>
<val1>100</val1>
<val2>200</val2>
<val3>300</val3>
<val4>400</val4>
</message2>
I have to parse the values (val) and i could not use XML::Simple module. The parsing should be started from <message1> and i have to put the values in an array till </message1> and then i have to repeat this for <message2> till </message2>.
Pictorially it is like
<message1>
----100
----200
----300
----400
</message1>
<message2>
----100
----200
----300
----400
</message2>
Can any one help me .. I am struggling a lot
Thanks
Senthil kumar

Answer 1

Since we're back in 1999, I think I would forget about strict and warnings, use symbolic references and string eval, and be done with it:
#!/usr/bin/perl
while( <DATA>)
{ s{<(message\d)>}{\#$1=(}; # #message1=(
s{<val\d>}{}; #
s{<\/val\d>}{,}; # ,
s{</message\d>}{);}; # );
$s.=$_;
};
eval $s;
$,= ", "; $\= "\n";
foreach (1..2) { print "\#message$_: ", #{"message$_"}; }
__DATA__
<message1>
<val1>100</val1>
<val2>200</val2>
<val3>300</val3>
<val4>400</val4>
</message1>
<message2>
<val1>100</val1>
<val2>200</val2>
<val3>300</val3>
<val4>400</val4>
</message2>
(in case that's not clear: that's a joke! As they say "Have you tried using an XML parser instead?")

Answer 2

Assuming your input is completely regular as you show, the following should work.
But you are far better off getting a real XML parser to work, by wrapping a root element around all your content or by parsing each message separately.
use strict;
use warnings;
my %data;
while (<>) {
# skip blank lines
next unless /\S/;
my ($tag) = /^<(.*)>$/
or warn("expected tag, got $_ "), next;
$data{$tag} ||= [];
while (<>) {
last if /^<\/\Q$tag\E>$/;
my (undef, $value) = /^<val(\d+)>(.*)<\/val\1>$/
or warn("expected val, got $_ "), next;
push #{ $data{$tag} }, $value;
}
}
use Data::Dumper;
print Dumper \%data;