this code supposed to look for all demo.txt in the disk and change them from "demo" to "demodemo997182625" and then check if the file has changed or not

$found = 0;
$notfound = 0;


foreach ($file in Get-ChildItem -Path C:\ -Recurse -Filter demo.txt -ErrorAction SilentlyContinue )
{
  (Get-Content $file).Replace("demo","demo997182625") | Set-Content $file

   $x = (Get-Content $file).contain("demo997182625")


   if($x -eq $null){

  $found = 1   $found;
  }

  else {

  $notfound = 1   $notfound;
  
  }

}            
Write-Host "Changed" $found;
Write-Host "Not Changed" $notfound;



     

CodePudding user response：

A few remarks on your code:

• the .Replace() and .Contains() string methods work case-sensitive, so .Replace("demo","demo997182625") won't find and replace "Demo". To have it work case-insensitively, use the -replace operator instead.
• updated files can be reprocessed by Get-ChildItem, unless you have that part finish completely first. The easiest way to do that is by enclosing it between brackets
• I would only save the file if there was something updated (i.e. the new value was found after -replace), otherwise leave it be
• Get-ChildItem returns both FileInfo and DirectoryInfo objects. Since you are interested in changing files only, append the -File switch
• best use the FullName property of the found file on the Get- and Set-Content cmdlets instead of the whole FileInfo object

$found = $notfound = 0

# surround the Get-ChildItem line with brackets, so it will finish before iterating on the result
# otherwise, it could reprocess files that were allready updated
foreach ($file in (Get-ChildItem -Path 'C:\' -Recurse -Filter 'demo.txt' -File -ErrorAction SilentlyContinue)) {
    # -replace uses regex, so surround the search string with '\b' boundary markers in order to do a whole-word search
    $content = (Get-Content -Path $file.FullName -Raw -Force) -replace '\bdemo\b', 'demo997182625'
    # test if the content now has the new value (again, use '\b' boundary markers)
    if ($content -match '\bdemo997182625\b') { 
        # save the updated file
        $content | Set-Content -Path $file.FullName -Force
        $found   
    } 
    else {$notfound  }

}            
Write-Host "Changed: $found"
Write-Host "Not Changed: $notfound"

P.S. If your search string contains characters that in regex have special meaning (see table below), you need to escape these with a backslash when using regex operators -replace and -match.

Special Characters in Regex