我正在寻找可以快速运行的命令（IF 测试），以查看是否可以连接到计算机。我做了一个 if 测试，如果它通过了，那么我将运行一系列命令来提取我需要的信息。如果第一次测试失败，那么它不会运行命令，否则每次测试都会失败，这将花费很长时间。
以下代码可以运行，但速度很慢，如果计算机不在网络上，则会导致“GUI（无响应）”。如果失败，我正在寻找可以更快地检查的方法。
if (Test-Path "\\$PCNAME\c`$")
{
# Slew of WMI commands go here.
}
我有时会查询大量计算机列表，如果其中大部分计算机处于关闭状态，则上述命令将需要大量时间才能完成。
【问题讨论】：
标签： powershell remote-connection
一个更好的解决方案，它使用基于：https://theolddogscriptingblog.wordpress.com/2012/05/11/wmi-hangs-and-how-to-avoid-them/ 的端口测试
这里是那里找到的脚本的修改版本以及使用它的一种方式的示例：
function Test-Port {
<#
.SYNOPSIS
Tests connection to port 135 on the SQL server, so I guess it is confined to M$ servers
.DESCRIPTION
.PARAMETER server
computername or IP address
.PARAMETER port
port defaults to 135
.PARAMETER timeout
in milliseconds, defaults to 1000
.EXAMPLE
Test-Port myserver.com
#>
Param(
[string] $server,
$port=135,
$timeout=1000, # milliseconds
[switch]$verbose
)
# Does a TCP connection on specified port (135 by default)
# Create TCP Client https://msdn.microsoft.com/en-us/library/system.net.sockets.tcpclient(v=vs.110).aspx
$tcpclient = new-Object system.Net.Sockets.TcpClient
# Initiate an asynchronous request to machine on Port
$iar = $tcpclient.BeginConnect($server,$port,$null,$null)
# Set the wait time
$wait = $iar.AsyncWaitHandle.WaitOne($timeout,$false)
# Check to see if the connection is done
if(!$wait)
{
# Close the connection and report timeout
$tcpclient.Close()
if($verbose){Write-Host Connection Timeout }
Return $false
}
else
{
# Close the connection and report the error if there is one
$error.Clear()
$tcpclient.EndConnect($iar) | out-Null
if(!$?){if($verbose){write-host $error[0]};$failed = $true}
$tcpclient.Close()
}
# Return $true if connection Establish else $False
if($failed){
return $false
} else {
return $true
}
}
#Found from using for a similar purpose that checking port 49153 was more reliable than 135
# also the test-connection is unnecessary and that very small timeouts, e.g., 10ms, worked on our network, which really speeds things up but you should test what works on your network
#Use like this
$computername = "myserver.com"
if (Test-Port -srv $computername -port 49153 -timeout 10) {
# Slew of WMI commands go here.
} else {
Write-Warning "Could ping $computername but NOT reach RPC port`n so can't use it for WMI"
}
【讨论】：
总结 sdjuan 的答案以快速检查 PCNAME 是否具有 C$ 驱动器共享，并允许 WMI 查找：
If ( (Test-Path "\\$PCNAME\c`$") -and (Get-WmiObject win32_bios -ComputerName $PCNAME) ) {
# Slew of WMI commands go here.
}
但是，通过我的测试，CimInstance 查找速度似乎更快，所以：
Get-CimInstance win32_bios -ComputerName $PCNAME
可能会产生更好的结果，但在脚本的其余部分保持一致。
【讨论】：
有两种简单的方法可以做到这一点：
一个是测试连接：
Test-Connection 192.168.0.2
Test-Connection -CompuetrName "SamsPC"
这可以用作布尔表达式，或与 $?运营商：
if (Test-Connection 192.168.0.1) {
do stuff
}
或
Test-Connection 192.168.0.1
if ($?) {
Do Stuff
}
另一种方法使用 .NET 类。
$Pinger = New-Object System.Net.NetworkInformation.Ping
$pResult = $Pinger.Send("192.168.0.1")
if ($pResult.Status -eq "Success") {
Do stuff
}
【讨论】：
您通常会看到 Test-Connection 用于此目的：
if (Test-Connection $PCNAME -Quiet -Count 1)
{
# Slew of WMI commands go here.
}
编辑：如果远程系统支持它，我怀疑使用 CIM 可能会更好。实施细节将取决于远程系统上是否启用了远程处理。
【讨论】：
Test-Connection a.k.a ping 而不是Get-WmiObject。这是因为WMI 是在您尝试访问的远程计算机上运行的服务
只需对测试连接超时脚本进行一些小的修改，您也可以测试 WMI 功能。只需用 get-wmiobject 调用替换 test-connection 即可获得完整的结果。这是一个修改后的函数：
Function Get-WMI {
param(
[Parameter(Mandatory = $True)]
[Object]$computer
)
$timeoutSeconds = 1 # set your timeout value here
$j = Start-Job -ScriptBlock {
# your commands here, e.g.
Get-WmiObject win32_bios -ComputerName $args[0]
} -ArgumentList $computer
#"job id = " + $j.id # report the job id as a diagnostic only
Wait-Job $j -Timeout $timeoutSeconds | out-null
if ($j.State -eq "Completed")
{
#connection to PC has been verified and WMI commands can go here.
$Answer = "WMI call WAS SUCCESSFULL to $computer"
}
elseif ($j.State -eq "Running")
{
#After the timeout ($timeoutSeconds) has passed and the test is
still running, I will assume the computer cannot be connected.
$Answer = "WMI is not running on or could not Connect to $computer"
}
return $Answer
}
我希望这对某人有所帮助。
【讨论】：
我知道这是事后的事，但我找到了解决方案。我正在寻找一个 if 测试来尝试测试连接，但是当它失败时，失败需要很长时间。建立连接后，它会立即通过。
$timeoutSeconds = 1 # set your timeout value here
$j = Start-Job -ScriptBlock {
# your commands here, e.g.
Test-Connection -ComputerName $args[0] -Count 1
} -ArgumentList $computer
#"job id = " + $j.id # report the job id as a diagnostic only
Wait-Job $j -Timeout $timeoutSeconds | out-null
if ($j.State -eq "Completed")
{
#connection to PC has been verified and WMI commands can go here.
$richtextbox1.Text = "Connection can be made to $computer"
}
elseif ($j.State -eq "Running")
{
#After the timeout ($timeoutSeconds) has passed and the test is still running, I will assume the computer cannot be connected.
$richtextbox1.Text = "Could not Connect to $computer"
}
我不确定我是从哪里得到这段代码的。我想我用过-adding a timeout to batch/powershell
我希望这对将来的某人有所帮助。
【讨论】：