REGEX Multi-line Search between 2 characters- Powershell - regex

Question

I am unable to apply many of the other powershell regex solutions to help solve my problem. The answer may very well already be on stackoverflow, but my lack of experience with powershell is prohibiting me from deducing how to maniupulate the solutions to my question.
I have a text file containing an XML document tree(I bring in the document tree as one large string into powershell)(edit 1) that includes the HTML tags to establish where certain content is. I need to steal the file name from in between the filename tags. Sometimes both tags and the file name are all on one line, and other times the tags are each on a seperate line as well as the file name. An example of the input data I have is below:
<files>
<file>
<fileName>
ThisTextFileINeedReturned.txt
</fileName>
<lastModifiedTime>1511883780000</lastModifiedTime>
<size>852192</size>
<isDirectory>false</isDirectory>
<isRegularFile>true</isRegularFile>
<isSymbolicLink>false</isSymbolicLink>
<isOther>false</isOther>
<group>group</group>
<transferStatus>Done</transferStatus>
</file>
<file>
<fileName>AnotherTextFileINeedReturned.txt</fileName>
<lastModifiedTime>1511883780000</lastModifiedTime>
<size>852192</size>
<isDirectory>false</isDirectory>
<isRegularFile>true</isRegularFile>
<isSymbolicLink>false</isSymbolicLink>
<isOther>false</isOther>
<group>group</group>
<transferStatus>Done</transferStatus>
</file>
I have created the following code to find the content within the tags thus far. It works if the filename tags and the file name are on the same line. The problem I'm having is in the instance where they are all on seperate lines (the example I provided above). I have already managed to transfer the large string above into $xmldata.
$xmldata -match '<fileName>(.*?)(</fileName>)'
$matches
Using the example text I displayed above, the output I receive is as follows:
<fileName>AnotherTextFileINeedReturned.txt</fileName>
I'm ok with receiving the tags, but I also need the name of the file that is on multiple lines. Like this...
<fileName>
ThisTextFileINeedReturned.txt
</fileName>
<fileName>AnotherTextFileINeedReturned.txt</fileName>
Or any variation that would give me both of the names of the text files. I have seen the (?m) part used before, but I haven't been able to successfully implement it. Thanks in advance for the help!! Let me know if you need any other information!

Answer 1

You should be able to get around that without using any regex. Powershell supports XML pretty well. Extracting the filename would be as easy as:
$Xml = #"
<files>
<file>
<fileName>
ThisTextFileINeedReturned.txt
</fileName>
<lastModifiedTime>1511883780000</lastModifiedTime>
<size>852192</size>
<isDirectory>false</isDirectory>
<isRegularFile>true</isRegularFile>
<isSymbolicLink>false</isSymbolicLink>
<isOther>false</isOther>
<group>group</group>
<transferStatus>Done</transferStatus>
</file>
<file>
<fileName>AnotherTextFileINeedReturned.txt</fileName>
<lastModifiedTime>1511883780000</lastModifiedTime>
<size>852192</size>
<isDirectory>false</isDirectory>
<isRegularFile>true</isRegularFile>
<isSymbolicLink>false</isSymbolicLink>
<isOther>false</isOther>
<group>group</group>
<transferStatus>Done</transferStatus>
</file>
</files>
"#
Select-Xml -Content $Xml -XPath "//files/file/fileName" | foreach {$_.node.InnerXML.Trim()}

Answer 2

You not explainen how you get your data but I guess you are using Get-Content to retrieve your source file. Get-Content reads the content one line at a time and returns a collection of objects, each of which represents a line of content. In other words, you're probably doing a Match on each separate line and therefor do no find the matches that are spread over multiple lines.
If this is indeed the case, the solution would be to simply join the lines first:
($xmldata -Join "") -match '<fileName>(.*?)(</fileName>)'
And check your matches, e.g.:
$Matches[0]