Extract specific data - powershell

Question

Please help. I am trying to extract multiple filenames from the following .xml file. I then need to copy the list of files from one folder to another. A part of the XML I have posted below:
<component>
<altname>HP Broadcom Online Firmware Upgrade Utility for VMware 5.x</altname>
<filename>CP021404.scexe</filename>
<name>HP Broadcom Online Firmware Upgrade Utility for VMware 5.x</name>
<description>This package contains vSphere 5.1 and VMware </description>
<component>
<component>
<altname>Online ROM Flash - Power Management Controller </altname>
<filename>CP021615.scexe</filename>
I used Windows PowerShell as below and got the output, but the output contains filenames (CP021404.scexe, CP021614.scexe below), line# and symbol still in it. What am I doing wrong on my first PS attempt?
PowerShell
$input_path = ‘C:\PowerShell\hpsum_inventory.xml’
$output_file = ‘C:\powershell\hpsum_inventory-o.xml’
$regex = ".exe"
select-string -Path $input_path -Pattern $regex -AllMatches > $output_file
Output
PowerShell\hpsum_inventory.xml:8: <filename>CP021404.scexe</filename>
PowerShell\hpsum_inventory.xml:18: <filename>CP021614.scexe</filename>

Answer 1

The problem is that you're using a RegEx match and the period character in RegEx matches any character except Line Feed/New Line characters, so it's matching any character followed by 'exe'. Really what you want to do is read the file as XML, and just output the <filename> nodes.
$input_path = ‘C:\PowerShell\hpsum_inventory.xml’
$output_file = ‘C:\powershell\hpsum_inventory-o.xml’
$regex = "exe$"
(Select-Xml -Path $input_path -XPath //filename).node.InnerText | ?{$_ -match $regex} | out-file $output_file
Edit: Ok, you need to incorporate that into a string, that's easy enough. We'll add a ForEach loop (I use the alias % for that) to the last line to insert the file name into a string.
(Select-Xml -Path $input_path -XPath //filename).node.InnerText | ?{$_ -match $regex} | %{"copy c:\powershell\$_ x:\firmware\"} | out-file $output_file
Edit2: Ok, so you want the knowledge in general of how to match text in a file. Can do! Select string will do what you want actually, it just wasn't the best method in general for the example you gave earlier. This gets a bit more interesting, since you need to be familiar with RegEx matching patterns, but other than that it's fairly straight forward. You want to use the -Pattern match again, but let me suggest a better pattern:
"filename>(.*?)<"
That looks for the filename tag, including closing > on it, and grabs everything up to the next < character. The () denote a capturing group, so the rest is ignored as far as the capture goes. Then we pipe to a ForEach loop, and for each line that it finds that matches we select the Matches property, and the second Group property of that (the first contains the whole text, including the filename> and < bits). So it looks like this:
$input_path = 'C:\PowerShell\hpsum_inventory.xml'
$output_file = 'C:\powershell\hpsum_inventory-o.xml'
$regex = "filename>(.*?)<"
select-string -Path $input_path -Pattern "filename>(.*?)<"|%{$_.matches.groups[1].value}
Now that only gets the file names. If we want to incorporate the rest of your thing about inserting it into text you enclose the part in the ForEach loop inside a sub-expression $() and then put that into your double quoted string like such:
select-string -Path $input_path -Pattern "filename>(.*?)<"|%{"copy c:\powershell\$($_.matches.groups[1].value) x:\firmware"}|Out-File $output_file
Personally I would suggest not doing that directly as it limits you. I'd collect the data in an array, then pipe that array into a process that does what you want, but then at least you have the collection so you can do with it what you want.
$input_path = 'C:\PowerShell\hpsum_inventory.xml'
$output_file = 'C:\powershell\hpsum_inventory-o.xml'
$regex = "filename>(.*?)<"
$Filenames = select-string -Path $input_path -Pattern "filename>(.*?)<"|%{$_.matches.groups[1].value}
$Filenames|%{"copy c:\powershell\$_ x:\firmware"}|Out-File $output_file
Why do it that way? What if you don't want to over-write something? Then you can do something like:
$Filenames|?{$_ -notin (GCI X:\firmware -file|select -expand name)}|%{"copy c:\powershell\$_ x:\firmware"}|Out-File $output_file
For your collection of serial numbers, try the regex pattern of:
"Serial Number: (\S*)"
In RegEx there are a few escaped characters that have special meaning, and capitalizing them inverts that meaning. \s means whitespace, so spaces, tabs, what not. Doing it as a capital means something that is NOT whitespace. The asterisk means however many of the previous thing (not whitespace) it can find. So this looks for 'Serial Number: ' and then captures everything after that until it reaches the end of the line or encounters whitespace. Check out this link to see how it works.