Check if a file exists or not in Windows PowerShell?

Question

I have this script which compares files in two areas of the disk and copies the latest file over the one with the older modified date.

$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
       }
}

Here is the format of files-to-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

I would like to modify this so that it avoids doing this if the file does not exist in both areas and prints a warning message. Can someone tell me how I can check if a file exists using PowerShell?

score 291 · Accepted Answer · answered Aug 07 '15 at 15:21

291

Just to offer the alternative to the Test-Path cmdlet (since nobody mentioned it):

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

Does (almost) the same thing as

Test-Path $path -PathType Leaf

except no support for wildcard characters

answered Aug 07 '15 at 15:21

Mathias R. Jessen

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1

See also: [A better way to check if a file exists or not in PowerShell](http://stackoverflow.com/a/31888581/450913) – orad Aug 08 '15 at 17:37
1

@orad Yes, I saw it, posted an answer with a negated Exists() call, but was not met with the same positive response ;-) – Mathias R. Jessen Aug 08 '15 at 19:27
5

Using `[System.IO.File]::Exists` also [resolves relative paths differently](https://stackoverflow.com/q/11246068/1394393), and `Test-Path` can be used with non-filepaths (e.g., registry locations). Use `Test-Path`. – jpmc26 Jan 20 '18 at 00:26
The Exists() one didn't work for me with relative paths. Test-Path worked great. – Jamie Aug 18 '18 at 00:12
2

@Jamie Native .NET methods usually resolve paths relative to the working directory of the process, not necessarily the current FileSystem path in powershell. You could do `[System.IO.File]::($(Join-Path $PWD $path))` – Mathias R. Jessen Aug 18 '18 at 14:09
1

And in case you didn't guess it's `[System.IO.Directory]::Exists($path)` for folders. Both support UNC paths on my system, but to do hidden shares remember to escape the `$` in the path as "`$" – Chris Rudd May 14 '19 at 17:32
This will return `$False` if a file is hidden. At least for me anyway. – Ste Jul 24 '21 at 13:41

arco444 · Answer 2 · 2017-10-02T09:07:25.720

108

Use Test-Path:

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

Placing the above code in your ForEach loop should do what you want

edited Oct 02 '17 at 09:07

answered Aug 07 '15 at 14:21

arco444

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score 38 · Answer 3 · edited Jul 13 '20 at 14:25

38

You want to use Test-Path:

Test-Path <path to file> -PathType Leaf

edited Jul 13 '20 at 14:25

SharpC

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answered Aug 07 '15 at 14:21

GodEater

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score 12 · Answer 4 · answered Aug 07 '15 at 14:22

12

The standard way to see if a file exists is with the Test-Path cmdlet.

Test-Path -path $filename

answered Aug 07 '15 at 14:22

Mike Shepard

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score 9 · Answer 5 · answered Aug 07 '15 at 14:24

9

You can use the Test-Path cmd-let. So something like...

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

answered Aug 07 '15 at 14:24

Speerian

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score 2 · Answer 6 · edited Jul 23 '19 at 21:38

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
  }
}

score -5 · Answer 7 · answered Jul 03 '17 at 08:51

-5

Test-Path may give odd answer. E.g. "Test-Path c:\temp\ -PathType leaf" gives false, but "Test-Path c:\temp* -PathType leaf" gives true. Sad :(

answered Jul 03 '17 at 08:51

Zoltan Hernyak

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Check if a file exists or not in Windows PowerShell?

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