How to process Custom log data using Powershell? - powershell

Question

I have a log file which has data separated with "|" symbol. Like
"Username|servername|access|password|group"
"Username|servername|access|password|group"
I need to validate the data. And, If the group column(record) is missing information or empty. I need to write only that row into another file. Please help me. Thanks in Advance.

Answer 1

If you're just checking for missing data, you can run a quick check using a regex of '(\S+\|){4}\S+'. Use Get-Content with the -ReadCount parameter, and you can work in batches of a few thousand records at a time, minimizing disk i/o and memory usage without going through them one record at a time.
Get-Content $inputfile -ReadCount 2000 |
foreach {
$_ -notmatch '(\S+\|){4}\S+' |
Add-Content $outputfile
}

Answer 2

You could use 'Import-CSV with -Delimiter '|'. If your file doesn't have a header line, you would also need to use -Header to define it. You could then use Where to filter for the empty Group lines and Export-CSV with -Delimiter again to create a new file of just those lines.
For example:
Import-CSV 'YourLog.log' -Delimiter '|' -Header 'Username','Servername','Access','Password','Group' |
Where {$_.'Group' -eq ''} |
Export-CSV 'EmptyGroupLines.log' -Delimiter '|'

Answer 3

If your group column is always in the same place, which it looks like it is, you could use the split method. You can certainly neaten the code up. I have used the below as an example as to how you could use split.
The foreach statement is to iterate through each line in your file.
if (!$($groupstring.Split('|')[4])) checks if it is null.
$groupstring = 'Username|servername|access|password|group'
$groupstring.Split('|')[4]
foreach ($item in $collection)
{
if (!$($groupstring.Split('|')[4]))
{
Write-Host "variable is null"
}
}
Hope this helps.
Thanks, Tim.