use strict; use warnings; use Data::Dumper; 

my $replacementData=<<'REPDATA'
"new/path/desired/data"
"new/path/desired/data"
"new/path/desired/data"
REPDATA
;

populateHash(); 

sub populateHash{
my $fileContent; 
if (0){ 

	my $inputFile = 'input.txt';
	
	$fileContent = do {
		open(my $fileHandle, $inputFile ) or die "Could not open file '$inputFile ' $!";
	
		local $/;
		<$fileHandle>;
	};
}
else { $fileContent = do { local $/;<DATA>;};}

	my $hashData = truncateText($fileContent, "key1 => {", "key2 =>");
print 'hashdata:'.$hashData."\n\n";
# notice change to first END_SEARCHPATHS to match your sample data 
	my $dataToReplace = truncateText($hashData, "END_SEARCHPATHS", "END_SEARCH_PATHS");
print 'torep1:'.$dataToReplace."\n\n";


	#Removes Comments works best if called multiple times
#       $dataToReplace =~ s/\#.*//smg;
#	$dataToReplace =~ s/\#.*//;
#	$dataToReplace =~ s/\#.*//;
#	$dataToReplace =~ s/\#.*//;
#print 'torep:2'.$dataToReplace."\n";

        #replacementData was gathered in another function and stored in a global variable
# notice addition of \n to replacement to put first on its own line 
	$fileContent =~ s/\Q$dataToReplace\E/\n$replacementData/;


print 'Res:'.$fileContent."\n";
#	print Dumper($fileContent);

}

sub truncateText{
	#Truncates text by removing everything before and and after the passed in variables
	
	my($text, $beginString, $endString) = @_;

	my $truncatedText;

	if($text =~ /\Q$beginString\E(.*?)\Q$endString\E/s){
		$truncatedText = $1;
		#print $truncatedText;	
	}

	return $truncatedText;

}

__DATA__
key1 => {
        #some data i don't need
        #more data i don't need
        <<'END_SEARCHPATHS',
        #block of data I want to replace
        "some/path/to/some/file"
        "some/path/to/some/file"
        "some/path/to/some/file"
        "some/path/to/some/file"
        "some/path/to/some/file"
        "some/path/to/some/file"
END_SEARCH_PATHS
}
key2 => {
        <<'END_SEARCHPATHS',
        #another block of data to replace
        "another/path/to/some/file"
        "another/path/to/some/file"
        "another/path/to/some/file"
        "another/path/to/some/file"
END_SEARCH_PATHS
}