my $root = $doc->documentElement();
for my $node ($root->findnodes(
   '/searchresult/document[ uid/text()="16b3" ]'
)) {
   $node->parent()->removeChild($node);
}
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The square brackets in the XPath are like a WHERE clause in SQL.

What have you tried? How did it fail? We can see your specification but this isn't a code writing service. You could look at XML Technologies from the tutorials section of this site, or super search/google Search the Monastery for similar problems.

The following is one possible solution; it's probably not the most "elegant" or "parsimonious", but it does what you describe for the kind of xml stream you have:

#!/usr/bin/perl

use strict;
use warnings;
use XML::LibXML;

die "Usage: $0  file.xml bad_uid ...\n"
    unless ( @ARGV > 1 );

my $xml_file = shift;
my %bad_uids = map { $_ => undef } @ARGV;

my $xml = XML::LibXML->new;
my $dom = $xml->parse_file( $xml_file );

my @kill_list;
for my $document ( $dom->getElementsByTagName( "document" )) {
    my ( $uid ) = $document->getElementsByTagName( "uid" );
    push @kill_list, $document if ( exists( $bad_uids{ $uid->textConte
+nt } ));
}
warn sprintf( "Removing %d document elements from %s\n",
              scalar @kill_list, $xml_file );
$_->unbindNode for ( @kill_list );

rename $xml_file, "$xml_file.old" or die "Unable to rename $xml_file\n
+";
open( NEW, ">", $xml_file ) or die "Unable to write new $xml_file\n";
print NEW $dom->toString;
close NEW;
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I realize that by providing a complete solution like this, I may be denying you the joy and satisfaction of reading the XML::LibXML manuals and doing experimentation on your own to reach your goal. If that's the case, I deeply regret it. (Those man pages are really really good.)

Please do explore the man pages for this module and its various sub-modules, because you will learn a lot from them. Rest assured that LibXML would most likely give you other ways to do this task that may be better for your particular needs.

open input.xml ;
delete //*[uid='16b3'] ;
save :b ;
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