powershell - Windows Powershell - 如何仅在某些 Windows 服务更改时重新显示它们的状态？

Question

我刚刚开始使用 Powershell。我有一个 bat 文件，它只是启动以下 PowerShell 脚本，然后每 5 秒重新显示我感兴趣的服务的状态。它工作正常(虽然我可以使用一些关于如何使这个更干净的指针)，除了每次重新绘制屏幕时都会有一个短暂的烦人的闪烁。所以，我想改变这一点，使 sleep 间隔为1秒或500毫秒，但仅在内容发生变化时才进行重绘。或者，如果无条件地重新绘制 dos 屏幕更容易，而不会导致它闪烁，那么我也会对这个解决方案感到满意。也请帮我清理代码。到目前为止，我害怕 PowerShell 中的函数、变量等，因为当我尝试使用 C 系列/Python 语法和构造时，PS 经常对我大喊大叫。 PS 与 Python、Java 等有些不同，我还没有弄清楚它的原理。

# When you run this script, it will show a simple window with the status of the services;

# Do we want to XYZ as well?
# To assign $true value, use:
#PowerShell.exe .\ShowServices.ps1 -showXYZ:$true
#param([switch]$showXYZ=$false)
param([switch]$showXYZ=$true)

# Build a regex for services
$servicesRegex = "Microsoft.*|Network.*"
if ($showXYZ -eq $true) { $servicesRegex = $servicesRegex + "|XYZ.*" }

# Controlling the appearance of the window
$pshost = get-host
$pswindow = $pshost.ui.rawui

$newsize = $pswindow.buffersize
$newsize.height = 3000
$newsize.width = 50
$pswindow.buffersize = $newsize

$newsize = $pswindow.windowsize
$newsize.height = 10
$newsize.width = 50
$pswindow.windowsize = $newsize

$global:CurrentUser = [System.Security.Principal.WindowsIdentity]::GetCurrent()
#$global:ComputerName = gc env:computername
#$pswindow.WindowTitle = "Service statuses for {0} on {1}." -f $CurrentUser.Name, $ComputerName
$pswindow.WindowTitle = "Service statuses for {0}." -f $CurrentUser.Name

# Clear the screen once
clear

# Formatting details.
[int]$global:len1 = 35
[int]$global:len2 = 8
[int]$global:sleepInterval = 5 #seconds - I want this to be more frequent, but not annoying.

function printHeader
{
  Write-Host("") # Blank line
  [string]$line = "{0,-$global:len1}  {1,-$global:len2}" -f "Service Name", "Status"
  Write-Host $line
  Write-Host("_" * $global:len1 + "  " + "_" * $global:len2)
}

function printService($serviceObject)
{
  [string]$foreColor = "yellow" # Default color, if neither Stopped nor Running
  if ($serviceObject.status -eq "Stopped") {$foreColor = "red" }
  if ($serviceObject.status -eq "Running") {$foreColor = "green" }
  [string]$outStr = "{0,-$global:len1}  {1,-$global:len2}" -f $serviceObject.displayname, $serviceObject.status
  Write-Host $outStr -foregroundcolor $foreColor #-backgroundcolor white
}

# The meat of it.
while($true)
{
  printHeader
  Get-Service | Where-Object {$_.name -match $servicesRegex} | ForEach-Object { printService($_) }
  Start-Sleep -s $global:sleepInterval # Sleep x seconds
  clear
}

Answer 1

尝试将脚本的最后一部分更改为:

# The meat of it.
$data = @()
while($true)
{
    $new = Get-Service | Where-Object {$_.name -match $servicesRegex}
    if (Compare-Object $data $new -Property Status) { 
        $data = $new
        clear
        printHeader
        $data | ForEach-Object { printService($_) }
    }
    Start-Sleep -s $global:sleepInterval # Sleep x seconds    
}