How can I extract XML from a text document?

Question

I have tons of text documents containing useless text and a section of XML. I would like to use either Mac Automator or Apple Script to pull the XML section out and place it in a new document with a .xml extension. How can I do that?
Here is a sample of the XML section that I need to pull:
- ---Start ACNS XML
<?xml version="1.0" encoding="UTF-8"?>
<Infringement xsi:schemaLocation="http://www.movielabs.com/ACNS/ACNS2v1.xsd" xmlns="http://www.movielabs.com/ACNS" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">           <Case>
<ID>22242387629</ID>
<Status>OPEN</Status>
<Severity>Normal</Severity>
</Case>
<Complainant>
<Entity>MPAA Search and Notify</Entity>
<Contact></Contact>
<Address></Address>
<Phone>5555555555</Phone>
<Email>[email protected]</Email>
</Complainant>
<Service_Provider>
<Entity>Some Place, Somewhere</Entity>
<Contact></Contact>
<Address>Some Place, Somewhere  </Address>
<Phone></Phone>
<Email>[email protected]</Email>
</Service_Provider>
<Source>
<TimeStamp>2011-12-02T23:41:59.94Z</TimeStamp>
<IP_Address>127.0.0.1</IP_Address>
<Port>64153</Port>
<Type>P2P</Type>
<SubType BaseType="P2P" Protocol="BitTorrent" />
<UserName></UserName>
<Number_Files>1</Number_Files>
</Source>
<Content>
<Item>
<TimeStamp>2011-12-02T23:41:59.94Z</TimeStamp>
<AlsoSeen Start="2011-12-02T23:40:00.11Z" End="2011-12-02T23:41:59.94Z"></AlsoSeen>
<Title>asdfasdf (2011)</Title>
<Artist></Artist>
<FileName>asdfasdf (2011) DVDRip XviD-MAXSPEED</FileName>
<FileSize>1580908467</FileSize>
<Type>Video</Type>
<Hash Type="SHA1">8FB7B1F4984AB6E0746B43D2B82D4ED8102984D5</Hash>
</Item>
</Content>
<History></History>
<Notes></Notes><Type Retraction="false">DMCA</Type>
<Detection>
<Asset>
<OriginalAssetName>asdfasdf (2011)</OriginalAssetName>
</Asset>
<ContentMatched Audio="false" Video="true" Text="false" />
<HashMatched>true</HashMatched>
<VerificationID>Manual and automated watermark verification</VerificationID>
</Detection>
<Verification>
<VerificationLevel Type="DT">2</VerificationLevel>
</Verification>
<TextNotice><![CDATA[12-03-2011

Answer 1

XML portion always starts with <Infringement and ends with </Infringement>.
Actually, it doesn't... the XML starts with the <?xml> tag, but that's just me being pedantic
Given what you've said, though, it's easy to extract the XML data from a given block of text.
First, read the source data:
set theText to read file "path:to:the:file"
Then you can extract the XML via something like:
set start_tag to "<?xml"
set end_tag to "</Infringement>"
set start_of_data to offset of start_tag in theText
set end_of_data to (offset of end_tag in theText) + (-1 + (length of end_tag))
set theXML to text start_of_data through end_of_data of theText
Now you can write that data to a file:
set theFile to open for access file ((path to desktop as text) & "output.xml" as text) with write permission
set eof theFile to 0
write theXML to theFile starting at 0
close access theFile
If you have multiple files you can either run this in a loop that iterates over the files, or save the script as a droplet, then drop the files onto the script icon. Let me know if you need help with that, too.