Powershell - Find If PCs become alive on the network

[TiZakit]

Hey all,

I'm kind of new to scripting and what have you, but I needed something to suit a particular task: I need to ping a list of PCs at all times, and if it becomes alive, I need to know about it. (Passively, I don't need an alert or anything)

I figured the best way to do this was in powershell. I pieced this together with a ton of googling. I'm open to suggestions/improvements as well if you guys have them.

One thing that I cannot figure out, is why when I add to an array, it outputs the array index to the console. If anyone has tips of suppressing that, please let me know.

Param(
    [Parameter(Mandatory=$true,Position=1)]
    $pclist
)

"=================================================="
"PC Pinger"
"Will ping a list of PCs forever, output any good pings to a file"
"Usage .\pinger pclist"
"=================================================="
$d = Get-Date -Format o | foreach {$_ -replace ":", "."}
$outfile = $d + ".csv"
$infile = Get-Content $pclist
$servers = New-Object System.Collections.ArrayList
$removelist = New-Object System.Collections.ArrayList
$counter = 0
$goodcounter = 0
$alive

"==================================="
"Input List = $pclist"
"Output List = $outfile"
"==================================="

if (Test-Path $outfile) {"Deleting file $outfile"}
if (Test-Path $outfile) {Remove-Item $outfile}

#add PCs to array $servers from #infile
foreach($i in $infile) {
$servers.Add($i)
}

#The Main Loop - Will execute until Ctrl+C
while(1){
#Loop through the $servers list
foreach ($i in $servers) {
if ($counter -gt 10000) {$counter=0}
"Ping attempts: $counter Ping Success: $goodcounter" 
$alive = Test-Connection -ComputerName $i -Count 1 -Delay 1 -TimeToLive 10 -Quiet
$counter++
#If PC pings, then add to file, and add to list to be removed, goodcounter++
if($alive) { 
Add-Content -Path $outfile "$i,$alive"
$removelist.Add($i)
$goodcounter++
}
}
#Remove the object from the $servers array, then delete the $removelist
foreach ($i in $removelist) {$servers.Remove($i)}
$removelist = New-Object System.Collections.ArrayList
}

 

[TiZakit]

Updated. It will now output to a file and delete PCs from the list.

I've been running this for the past few days. It has allowed me to catch a few PCs on the network.

Param(
    [Parameter(Mandatory=$true,Position=1)]
    $pclist
)

"=================================================="
"PC Pinger"
"Will ping a list of PCs forever, output any good pings to a file"
"Usage .\pinger pclist"
"=================================================="
$d = Get-Date -Format o | foreach {$_ -replace ":", "."}
$outfile = $d + ".csv"
$infile = Get-Content $pclist
$servers = New-Object System.Collections.ArrayList
$removelist = New-Object System.Collections.ArrayList
$counter = 0
$goodcounter = 0
$listcounter = 0
$alive

if (Test-Path $outfile) {"Deleting file $outfile"}
if (Test-Path $outfile) {Remove-Item $outfile}

#add PCs to array $servers from #infile, delete the file, so we can recreate later
foreach($i in $infile) {
$servers.Add($i)
}


"==================================="
"Input List = $pclist"
"Output List = $outfile"
"==================================="

#The Main Loop - Will execute until Ctrl+C
while(1){
$listcounter++
#Loop through the $servers list
foreach ($i in $servers) {
clear
"List Iteration: $listcounter Ping attempts: $counter Ping Success: $goodcounter"
$alive = Test-Connection -ComputerName $i -Count 1 -Delay 1 -TimeToLive 10 -Quiet
$counter++
#If PC pings, then add to file, and add to list to be removed, goodcounter++
if($alive) {
$date = Get-Date 
Write-Host "Adding to List: $i,$alive,$date"
Add-Content -Path $outfile "$i,$alive,$date"
$removelist.Add($i)
$goodcounter++
}
}
#Remove the object from the $servers array, then delete the $removelist
foreach ($i in $removelist) {$servers.Remove($i)
Write-Host "Removing Machine: " $i
}
$removelist = New-Object System.Collections.ArrayList
#remove everything from the txt file as well. Consider this an option for a switch in the future
Remove-Item $pclist
foreach ($i in $servers) {Add-Content -Path $pclist "$i"}
}