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Pinging a Hostname with Timeout

  • 项目

Well, that's simple:

$ping = New-Object System.Net.NetworkInformation.Ping;
[bool]($ping.Send($computer, $pingTimeout).Status -ne 'Success');

It gets more interesting when we need to verify that $computer is actually valid.  We can use [System.Net.DNS]::GetHostAddresses(), but that emits an error if the host doesn't exist, which can be disconcerting if we're trying to write something that looks pretty.  In this case, we'll use trap {} to suppress the error message and get on with our lives:

& {trap { continue; } $script:hostEntry = [System.Net.Dns]::GetHostEntry($computer); }
[bool]$script:hostEntry   ; 

Put it all together, and we get:

 function Ping-Computer {
    param (
        [string]$computer,
        [int]$pingTimeout = 1000 # in milliseconds
    );

    if (!$computer) {
        Write-Warning "-computer not specified, required.";
        return $false;
    }

    $script:hostEntry = $null;
    & { trap { continue; } $script:hostEntry = [System.Net.Dns]::GetHostEntry($computer); }

    if (!$script:hostEntry) {
        Write-Warning "$computer is not known.";
        return $false;
    }

    $script:pingStatus = $null;
    & { trap { continue; } $script:pingStatus = (New-Object System.Net.NetworkInformation.Ping).Send($computer, $pingTimeout).Status; }

    if ($script:pingStatus -ne 'Success') {
        Write-Warning "$computer is not pingable.";
        return $false;
    }

    return $true;
}

Comments

  • Anonymous
    June 24, 2011
    Here's one that works for a list of computers: function Ping-Computer { param ( [string[]]$computer = @(), [int]$timeout = 1, [switch]$one ); foreach ($myComputer in $computer) { if (!$myComputer) { continue; } Write-Verbose "Processing $myComputer"; $pingStatus = $null; & { trap { Write-Warning "${computer}: $($_.Exception.Message)"; continue; } (New-Object System.Net.NetworkInformation.Ping).Send($myComputer,$timeout * 1000).Status | Set-Variable -Scope 1 -Name pingStatus; } if ($one) { $pingStatus -eq 'Success'; break; } else { $pingStatus | Select-Object -Property @{ name = 'name'; expression = { $myComputer; } }, @{ name = 'status'; expression = { $pingStatus -eq 'Success' } } } } }