检查 Windows PowerShell 中是否存在文件？

Question

我有这个脚本可以比较磁盘两个区域中的文件，并将最新的文件复制到修改日期较早的文件上。

$filestowatch=get-content C:\H\files-to-watch.txt

$adminFiles=dir C:\H\admin\admin -recurse | ? { $fn=$_.FullName; ($filestowatch | % {$fn.contains($_)}) -contains $True}

$userFiles=dir C:\H\user\user -recurse | ? { $fn=$_.FullName; ($filestowatch | % {$fn.contains($_)}) -contains $True}

foreach($userfile in $userFiles)
{

      $exactadminfile= $adminfiles | ? {$_.Name -eq $userfile.Name} |Select -First 1
      $filetext1=[System.IO.File]::ReadAllText($exactadminfile.FullName)
      $filetext2=[System.IO.File]::ReadAllText($userfile.FullName)
      $equal = $filetext1 -ceq $filetext2 # case sensitive comparison

      if ($equal) { 
        Write-Host "Checking == : " $userfile.FullName 
        continue; 
      } 

      if($exactadminfile.LastWriteTime -gt $userfile.LastWriteTime)
      {
         Write-Host "Checking != : " $userfile.FullName " >> user"
         Copy-Item -Path $exactadminfile.FullName -Destination $userfile.FullName -Force
       }
       else
       {
          Write-Host "Checking != : " $userfile.FullName " >> admin"
          Copy-Item -Path $userfile.FullName -Destination $exactadminfile.FullName -Force
       }
}

这里是文件格式-watch.txt

content\less\_light.less
content\less\_mixins.less
content\less\_variables.less
content\font-awesome\variables.less
content\font-awesome\mixins.less
content\font-awesome\path.less
content\font-awesome\core.less

我想对此进行修改，以便在文件不存在于两个区域时避免执行此操作并打印一条警告消息。谁能告诉我如何使用 PowerShell 检查文件是否存在？

Answer 1

您想使用 Test-Path:

Test-Path <path to file> -PathType Leaf

Answer 2

使用Test-Path:

if (!(Test-Path $exactadminfile) -and !(Test-Path $userfile)) {
  Write-Warning "$userFile absent from both locations"
}

将上面的代码放在 ForEach 循环中应该可以满足您的需求

Answer 3

查看文件是否存在的标准方法是使用 Test-Path cmdlet。

Test-Path -path $filename

Answer 4

您可以使用 Test-Path cmd-let。所以像...

if(!(Test-Path [oldLocation]) -and !(Test-Path [newLocation]))
{
    Write-Host "$file doesn't exist in both locations."
}

Answer 5

只是提供 the alternative to the Test-Path cmdlet（因为没有人提到它）：

[System.IO.File]::Exists($path)

做（几乎）与

相同的事情

Test-Path $path -PathType Leaf

除了不支持通配符

Answer 6

Test-Path 可能给出奇怪的答案。例如。 "Test-Path c:\temp\ -PathType leaf" 给出 false，但 "Test-Path c:\temp* -PathType leaf" 给出 true。悲伤:(

Answer 7

cls

$exactadminfile = "C:\temp\files\admin" #First folder to check the file

$userfile = "C:\temp\files\user" #Second folder to check the file

$filenames=Get-Content "C:\temp\files\files-to-watch.txt" #Reading the names of the files to test the existance in one of the above locations

foreach ($filename in $filenames) {
  if (!(Test-Path $exactadminfile$filename) -and !(Test-Path $userfile$filename)) { #if the file is not there in either of the folder
    Write-Warning "$filename absent from both locations"
  } else {
    Write-Host " $filename  File is there in one or both Locations" #if file exists there at both locations or at least in one location
  }
}

检查 Windows PowerShell 中是否存在文件？

Check if a file exists or not in Windows PowerShell?

powershell

powershell-3.0