The other day I came across a PowerShell question on StackOverflow about testing if a service was running on a group of machines.This sparked an idea for a tool to \"ping\" a service, in much the same way we ping a computer to see if it is up and running, or at least reachable. It is not difficult to use Get-Service, or even WMI, to connect to a service on a remote machine. But I thought it might be nice to have a few extras so I came up with Ping-Service.<\/p>\n
I suppose I could have called it Test-Service, but I liked the idea of pinging a service. Let me layout the core part then I'll touch on a few parts.<\/p>\n
[cmdletbinding()]<\/p>\n Param( [Parameter(Position=1,ValuefromPipeline=$True)] [switch]$Quiet Begin { Process { #get service from each computer if ($Quiet -and $service.status -eq \"Running\") { New-Object -TypeName PSObject -Property @{ End { } #function The function takes service and computer names as parameters. You have specify a service name but the computername defaults to the local computer. By default the function writes a custom object to the pipeline which I'll get to in a moment. But you can also use -Quiet which will return True if the service is running and false for anything else, including errors connecting to the service or computer. This allows you to use the command in an If statement.<\/p>\n
\nFunction Ping-Service {<\/p>\n
\n[Parameter(Position=0,Mandatory=$True,HelpMessage=\"Enter the name of a service\")]
\n[ValidateNotNullorEmpty()]
\n[string]$Name,<\/p>\n
\n[ValidateNotNullorEmpty()]
\n[string[]]$Computername=$env:computername,<\/p>\n
\n)<\/p>\n
\n Write-Verbose \"Starting $($myinvocation.mycommand)\"
\n Write-Verbose \"Pinging service $name\"
\n}<\/p>\n
\n Foreach ($computer in $computername) {
\n Write-Verbose \"Testing computer $computer\"<\/p>\n
\n $measure=Measure-Command {$service=Get-Service -Name $Name -ComputerName $Computer -ErrorAction SilentlyContinue -ErrorVariable ev}
\n $end=Get-Date<\/p>\n
\n #if quiet only return True if service is running
\n Write-Output $True
\n }
\n elseif ($Quiet) {
\n #status is something other than Running
\n Write-Output $False
\n }
\n elseif ($ev) {
\n $msg=\"Error with {0} service on {1}. {2}\" -f $Name,$Computer,$ev[0].Exception.message
\n Write-Verbose $msg
\n Remove-Variable ev<\/p>\n
\n Time=(Get-Date -displayhint Time);
\n Computername=$Computer;
\n Name=$name;
\n Displayname=$null;
\n Status=\"Unknown\";
\n Response=$measure.TotalMilliseconds;
\n Reply=$False
\n } | Select Time,Computername,Name,Displayname,Status,Response,Reply
\n }
\n else {
\n #otherwise, return a custom object
\n $service | Select @{Name=\"Time\";Expression={(Get-Date -displayhint Time)}},
\n @{Name=\"Computername\";Expression={$_.Machinename}},
\n Name,Displayname,Status,
\n @{Name=\"Response\";Expression={$measure.TotalMilliseconds}},
\n @{Name=\"Reply\";Expression={
\n if ($_.Status -eq \"Running\") {$True} else {$False}
\n }}
\n }
\n } #foreach
\n}<\/p>\n
\n Write-Verbose \"Ending $($myinvocation.mycommand)\"
\n}<\/p>\n
\n<\/code><\/p>\n