Powershell parse parts of a text file and save to CSV - parsing

Question

All, I'm very new to powershell and am hoping someone can get me going on what I think would be a simple script.
I need to parse a text file, capture certain lines from it, and save those lines as a csv file.
For example, each alert is in its own text file. Each file is similar to this:
--start of file ---
Name John Smith
Dept Accounting
Codes bas-2349,cav-3928,deg-3942
iye-2830,tel-3890
Urls hxxp://blah.com
hxxp://foo.com, hxxp://foo2.com
Some text I dont care about
More text i dont care about
Comments
---------
"here is a multi line
comment I need
to capture"
Some text I dont care about
More text i dont care about
Date 3/12/2013
---END of file---
For each text file if I wanted to write only Name, Codes, and Urls to a CSV file. Could someone help me get going on this?
I'm more a PERL guy so I know I could write a regex for capturing a single line beginning with Name. However I am completely lost on how I could read the "Codes" line when it might be one line or it might be X lines long until I run into the Urls field.
Any help would be greatly appreciated!

Answer 1

Text parsing usually means regex. With regex, sometimes you need anchors to know when to stop a match and that can make you care about text you otherwise wouldn't. If you can specify that first line of "Some text I don't care about" you can use that to "anchor" your match of the URLs so you know when to stop matching.
$regex = #'
(?ms)Name (.+)?
Dept .+?
Codes (.+)?
Urls (.+)?
Some text I dont care about.+
Comments
---------
(.+)?
Some text I dont care about
'#
$file = 'c:\somedir\somefile.txt'
[IO.File]::ReadAllText($file) -match $regex
if ([IO.File]::ReadAllText($file) -match $regex)
{
$Name = $matches[1]
$Codes = $matches[2] -replace '\s+',','
$Urls = $matches[3] -replace '\s+',','
$comment = $matches[4] -replace '\s+',' '
}
$Name
$Codes
$Urls
$comment

Answer 2

If the file is not too big to be processed in memory, the simple way is to read it as an array of strings. (What too big means is subject to your system. Anything sub-gigabyte should work without too much a hickup.)
After you've read the file, set up a head and tail counters to point to element zero. Move the tail pointer row by row forward, until you find the date row. You can match data with regexps. Now you know the start and end of a single record. For the next record, set head counter to tail+1, tail to tail+2 and start scanning rows again. Lather, rinse, repeat until end of array is reached.
When a record is matched, you can extract name with a regex. Codes and Urls are a bit trickier. Match the Codes row with a regex. Extract it and all the next rows unless they do not match the code pattern. Same goes to Urls data. If the file always has whitespace padding on rows that are data to previous Urls and Codes, you could use match whitespace count with a regexp to get data rows too.

Answer 3

Maybe something line this would to it:
foreach ($Line in gc file.txt) {
switch -regex ($Line) {
'^(Name|Dept|Codes|Urls)' {
$Capture = $true
break
}
'^[A-Za-z0-9_-]+' {
$Capture = $false
break
}
}
if ($Capture) {
$Line
}
}
If you want the end result as a CSV file then you may use the Export-Csv cmdlet.

Answer 4

According the fact that c:\temp\file.txt contains :
Name John Smith
Dept Accounting
Codes bas-2349,cav-3928,deg-3942
iye-2830,tel-3890
Urls hxxp://blah.com
hxxp://foo.com
hxxp://foo2.com
Some text I dont care about
More text i dont care about
.
.
Date 3/12/2013
You can use regular expressions like this :
$a = Get-Content C:\temp\file.txt
$b = [regex]::match($a, "^.*Codes (.*)Urls (.*)Some.*$", "Multiline")
$codes = $b.groups[1].value -replace '[ ]{2,}',','
$urls = $b.groups[2].value -replace '[ ]{2,}',','

Answer 5

If all files have the same structure you could do something like this:
$srcdir = "C:\Test"
$outfile = "$srcdir\out.csv"
$re = '^Name (.*(?:\r\n .*)*)\r\n' +
'Dept .*(?:\r\n .*)*\r\n' +
'Codes (.*(?:\r\n .*)*)\r\n' +
'Urls (.*(?:\r\n .*)*)' +
'[\s\S]*$'
Get-ChildItem $srcdir -Filter *.txt | % {
[io.file]::ReadAllText($_.FullName)
} | Select-String $re | % {
$f = $_.Matches | % { $_.Groups } | ? { $_.Index -gt 0 }
New-Object -TypeName PSObject -Prop #{
'Name' = $f[0].Value;
'Codes' = $f[1].Value;
'Urls' = $f[2].Value;
}
} | Export-Csv $outfile -NoTypeInformation