script to output event logs not accessing not working - csv

Question

I am new to powershell, Need to write a script to pull security logs and then place the data in a time stamped csv file in a location but I am getting I get stuck in a loop. My desired outcome is a CSV file in my directory with the security logs and time stamp for file name here is what I got for the part it is flagging.
Get-EventLog "Security" -After $Date `
| Where -FilterScript {$_.EventID -eq 4624 -and $_.ReplacementStrings[4].Length -gt 10 -and $_.ReplacementStrings[5] -notlike "*$"} `
| foreach-Object {
$row = "" | Select UserName, LoginTime
$row.UserName = $_.ReplacementStrings[5]
$row.LoginTime = $_.TimeGenerated
$eventList += $row
$variable | Export-Csv c:\output.csv
}
$eventList
Export-Csv : Cannot bind argument to parameter 'InputObject' because it is null.
At line:12 char:21
I am guessing the issue is here? Again my apologize very little scripting background, just trying to make a process better.
$variable | Export-Csv c:\output.csv

Answer 1

Yes, you don't define $variable within your script, that is why you getting this exception. It looks like you trying to export a bunch of EventLog entries as csv, so the Export-Csv cmdlet probably should belong outside the Foreach-Objectcmdlet. Maybe you want to do something like this:
Get-EventLog "Security" -After $Date `
| Where -FilterScript {$_.EventID -eq 4624 -and $_.ReplacementStrings[4].Length -gt 10 -and $_.ReplacementStrings[5] -notlike "*$"} `
| foreach-Object {
$row = "" | Select UserName, LoginTime
$row.UserName = $_.ReplacementStrings[5]
$row.LoginTime = $_.TimeGenerated
$row # this will put the current row to the pipeline
} | Export-Csv 'c:\output.csv'