title: Check if a file exists or not in Windows PowerShell?
body: <p>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. </p>
  
  <pre><code>$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 " &gt;&gt; user"
           Copy-Item -Path $exactadminfile.FullName -Destination $userfile.FullName -Force
         }
         else
         {
            Write-Host "Checking != : " $userfile.FullName " &gt;&gt; admin"
            Copy-Item -Path $userfile.FullName -Destination $exactadminfile.FullName -Force
         }
  }
  </code></pre>
  
  <p>Here is the format of files-to-watch.txt</p>
  
  <pre><code>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
  </code></pre>
  
  <p>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?</p>