#!/usr/bin/perl --
use XML::Twig;
BEGIN { *XML::Twig::Elt::x = *XML::Twig::Elt::get_xpath; }

use strict;
use warnings;

my $str = <<'EOF';
<fudge>
  <factory>
    <drop>
      <bindname>qqqqq</bindname>
      <bindpass>welcome</bindpass>
    </drop>
    <drop>
      <bindname>abcde</bindname>
      <bindpass>welcome</bindpass>
    </drop>
  </factory>
</fudge>
EOF

{
    my $t = XML::Twig->new(
        pretty_print  => 'indented',
        twig_handlers => {
            
            '//factory/drop' => sub {
                if ( not $_->x('bindname[string()=~/abcde/]') ) {
                    if ( my ($pass) = $_->x('bindpass[string()="welcome"]') ) {
                        $pass->set_text( uc $pass->text );
                    }
                }
            },
        },
    );
    $t->parse($str);
    $t->print();
}

{
    my $bozo = 0;
    my $t    = XML::Twig->new(
        pretty_print  => 'indented',
        twig_handlers => {

            '//factory/drop/bindname' => sub {
                $bozo = 1 if $_->text =~ /abcde/;
            },
            '//factory/drop/bindpass' => sub {
                if ( not $bozo and $_->text =~ /welcome/ ) {
                    $_->set_text( uc $_->text );
                }
                $bozo = 0;
            },
        },
    );
    $t->parse($str);
    $t->print();
}

__END__

##</code><code>##

#!/usr/bin/perl --
use strict;
use warnings;

use XML::XSH2;

xsh(<<'__XSH__');
open "fudge.xml";
ls --indent /;

pwd ;
cd /fudge/factory ;
pwd ;

foreach //drop {
    if not( bindname/text()[contains(.,'abcde')] ){
        set bindpass xsh:subst(
            bindpass/text(),
            "welcome",
            "W-e-l-c-o-m-e",
            "i"
        );
    };
};

ls --indent /;
save --indent :b /; # overwrite original file, :b means backup

__XSH__

__END__
$ perl xsh.922557.pl
parsing fudge.xml
done.
<?xml version="1.0"?>
<fudge>
  <factory>
    <drop>
      <bindname>qqqqq</bindname>
      <bindpass>welcome</bindpass>
    </drop>
    <drop>
      <bindname>abcde</bindname>
      <bindpass>welcome</bindpass>
    </drop>
  </factory>
</fudge>


Found 1 node(s).
/
/fudge/factory
<?xml version="1.0"?>
<fudge>
  <factory>
    <drop>
      <bindname>qqqqq</bindname>
      <bindpass>W-e-l-c-o-m-e</bindpass>
    </drop>
    <drop>
      <bindname>abcde</bindname>
      <bindpass>welcome</bindpass>
    </drop>
  </factory>
</fudge>


Found 1 node(s).
Document saved into file 'fudge.xml'.

$ ls -loanh fudge*
-rw-rw-rw-  1 0 252 2011-08-26 06:05 fudge.xml
-rw-rw-rw-  1 0 234 2011-08-26 06:05 fudge.xml~