Regex for extracting Data

[Amar Helloween Participant Points: 0Rank: Member]

Hello friends,

I am trying to write a script in powershell to capture some eventlog and extract the no.of times a domain got recycled.

Sample eventlog :

I have kept this log in a Variable say $Data.
Now I am looking for output something as below by parsing $Data variable :

Domain Name No.of Times recycled
—————– ————————–
a.org 2
b.com 1
c.co.in 3
d.com 1
s.org 1
se.com 1
b.ac.in 1

Kindly provide your suggestion on how this can be achieved.

[js Participant Points: 207Rank: Participant]

Here's a lazy attempt.

$counts = @{}

echo a.org,b.com,c.co.in,d.com,s.org,se.com,b.ac.in | 
foreach { 
  $counts[$_] = (select-string $_ log).count
}
    
$counts


Name                           Value
----                           -----
s.org                          1
a.org                          2
b.com                          1
c.co.in                        3
se.com                         1
d.com                          1
b.ac.in                        1

[Amar Helloween Participant Points: 0Rank: Member]

Thanks for the suggestion, Actually the above one is just a sample having 7 domain names, but in actual scenario it may have more than 300+ domains, so it will be difficult to pass each domain name.

Kindly suggest.

[Will Anderson Keymaster Points: 12Rank: Member]

Can you read the domains from Active Directory?

[js Participant Points: 207Rank: Participant]

I was trying to use convertfrom-string, but I can't get it to work. 🙁

$template = @'
{Domain*:a.org}
{Domain*:b.com}
'@

$testText = @'
A worker process serving application pool 'a.org(domain)(4.0)(pool)' has requested a recycle because it reached its private bytes memory limit.
A worker process serving application pool 'b.com(domain)(2.0)(pool)' has requested a recycle because it reached its private bytes memory limit.
'@

$testText | convertfrom-string -templatecontent $template 


Domain
------
A worker process serving application pool 'a.org(domain)(4.0)(pool)' has requested a recycle because it reached its private bytes memory limit.
A worker process serving application pool 'b.com(domain)(2.0)(pool)' has requested a recycle because it reached its private bytes memory limit.

[Amar Helloween Participant Points: 0Rank: Member]

Will Anderson – This domains are actually hosted on IIS, and not all of them will show application pool recycle error. so fetching from AD will not be possible.

[Max Participant Points: 2Rank: Member]

Assuming the format is the same:

Class domain{
    $name
    $counted = $false
}
Class recycleCount{
    $name
    $count
}
$log = Get-Content C:\temp\temp.log
$arrayDom = @()
$arrayFinal = @()

$log | %{if($_.contains("has requested a recycle")){
                $start = $_.indexof("'");
                $end = $_.indexof("(");
                $objDom = New-Object domain;
                $objDom.name = $_.Substring($start+1,$end-$start-1);
                $arrayDom += $objDom;
                }
           }
$arrayDom | %{$count = 0;
            if($_.counted -eq $false){
                $name = $_.name;
                $_.counted = $true;
                $count += 1;
                $arrayDom | %{if(($_.name -eq $name) -and ($_.counted -eq $false)){
                            $_.counted = $true;
                            $count+=1;
                            }
                        };
                        $objCnt = New-Object recycleCount;
                        $objCnt.name = $name
                        $objCnt.count = $count
                        $arrayFinal += $objCnt
                }
          }
$arrayFinal

[Tim Curwick Participant Points: 5Rank: Member]

Amar,

Try something like this:

$Data |
Where-Object { $_ -like '*has requested a recycle*' } |
ForEach-Object { $_.Split( "'(" )[1] } |
Group-Object |
Select-Object -Property Name, Count

[js Participant Points: 207Rank: Participant]

Nice! I tried that with -split.

$counts = @{} # associative array
select-string 'has requested a recycle' log |
foreach {
  $org = ($_ -split {$_ -in "'",'(' })[1]
  $counts[$org]++
}
$counts


Name                           Value                                           
----                           -----                                           
b.com                          1                                               
s.org                          1                                               
c.co.in                        3                                               
d.com                          1                                               
b.ac.in                        1                                               
a.org                          2                                               
se.com                         1                                               

[js Participant Points: 207Rank: Participant]

Here's a way to convert that $counts hashtable I made to an object:

foreach ( $key in $counts.keys ) {
  echo '' | select @{name='domain';expression={$key}},
    @{name='times';expression={$counts[$key]}} }


domain  times
------  -----
s.org       1
a.org       2
b.com       1
c.co.in     3
se.com      1
d.com       1
b.ac.in     1

[random commandline Participant Points: 10Rank: Member]

If you are not sure how large this log file will be, I recommend using switch statement.

# Match and add each domain name to list
$log = Get-ChildItem .\event.log
$nobj = New-Object System.Collections.ArrayList

switch -regex -File $log {
    "pool '(?'dn'.*)\(domain\).*requested a recycle" 
    {[void]($nobj.add($Matches['dn']))}
}

# Display number of domain name
$nobj | Group-Object | Select-Object Name,Count

[js Participant Points: 207Rank: Participant]

What does this part mean? Somehow .* becomes $matches['dn']?

(?'dn'.*)

[random commandline Participant Points: 10Rank: Member]

'(?'dn'.*)' is a named capture group. It will capture the domain name or in this case all text between the words 'pool' and 'domain.' Once captured, a hashtable ($Matches) is created.

() = text in parentheses will be captured
'.*' = any number of characters
?'dn' = give the capture group the name 'dn'

[js Participant Points: 207Rank: Participant]

I was reading about capture groups here, but the format used greater than and less than signs (this forum can't show them) instead of single quotes. https://ss64.com/ps/syntax-regex.html

[Curtis Smith Participant Points: 0Rank: Member]

They are both valid formats

IE

$inputval = 'abcdefghijklmnopqrstuvwxyz'

$inputval -match "(?.*)e.*v(?'afterV'.*)$"

$Matches

Results:

True

Name                           Value
----                           -----                                                                                                                                                                                                                             
afterV                         wxyz
beforeE                        abcd
0                              abcdefghijklmnopqrstuvwxyz

There is also another format (?P.*), but this format is not supported by .NET, and subsequently not supported in PowerShell.
Ref: http://www.regular-expressions.info/refext.html

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