Find & Replace in Files with PowerShell

Find and Replace text in all selected files in a folder.

Script

$SPath = 'D:\DataSelf\PowerShell\*.csv'     # Edit path
$FindStr    = 'xx'                          # Edit find & replace values
$ReplaceStr = "yy"
#-----------------------------------------------
Write-host "Search Path: $SPath"
Write-Host "  Find: $FindStr    Replace: $ReplaceStr "
Write-Host "-----------------------------------"
Write-Host "Files to search in $SPath"
$files = Get-ChildItem -Path $SPath  -verbose
foreach ($file in $files) {
   write-host $file.fullname
}
Write-Host "Start Find & Replace"
$files = Get-ChildItem -Path $SPath 
foreach ($file in $files) {
    if (Select-String -Path $file -Pattern $FindStr -verbose -list)  {
        write-host "Selected file : $file"  
        # Read & Display the contents of the file before Find/Replace
        $content = Get-Content -Path $file
        Write-Output $content
        Write-Host ""
        # Perform the replacement
        #>> $updatedContent = $content -replace $FindStr, $ReplaceStr  # Regular Expressions
        $updatedContent = $content.Replace($FindStr, $ReplaceStr)  # Simple string replacement
        $updatedContent | Set-Content -Path $file
         # Read & Display the contents of the file AFTER Find/Replace
        $content = Get-Content -Path $file.FullName
        Write-Host "After Find/Replace"
        Write-Output $content
        Write-Host ""
    }
}Lines 1 - 3:  Replace the literals with your search values.

Instructions:

Lines 1 - 3: Replace the literal strings with your file, find and replace values.

Only updates files that match the criteria in the $SPath and $FindStr variables.

Find & Replace Case In-sensitive

.Replace Method

$newContent = $content.Replace("hello", "Hi", [StringComparison]::OrdinalIgnoreCase)

Using the Replace() method with StringComparison.OrdinalIgnoreCase: The Replace() method allows you to specify a StringComparison parameter to control the comparison behavior. By setting it to OrdinalIgnoreCase, you can perform a case-insensitive replacement.

The .Replace method is an older method that doesn’t work in some contexts.

-ireplace Operator

Using the -ireplace operator: The -ireplace operator is similar to the -replace operator, but it performs a case-insensitive replacement. Here's an example:

   $content = "Hello World"
   $newContent = $content -ireplace "hello", "Hi"

Alternative Method for Simple Text (no regular expressions)

Here's a breakdown of the script:

Use the Get-ChildItem cmdlet to retrieve all the files within the specified folder (C:\folder) using the -File parameter to exclude directories.
Iterate over each file using the ForEach-Object cmdlet.
Use the Get-Content cmdlet to read the content of each file and store it in the $content variable.
Use the Replace() method to find and replace the desired text in the $content variable.
Use the Set-Content cmdlet to write the modified content back to the original file.

This script performs the find and replace operation without using the -replace operator. Instead, it leverages the Replace() method available on string objects in PowerShell.

Note: The Replace() method performs a case-sensitive replacement. If you need a case-insensitive replacement, you can use the -replace operator instead.

Alternative Method

Here's how the script works:

Get-ChildItem is used to retrieve all the files in the specified folder (C:\folder) with the .txt extension. The -Recurse parameter is used to search for files in subdirectories as well.
The resulting file objects are passed through the pipeline to the ForEach-Object cmdlet.
Within the ForEach-Object block, Get-Content is used to read the content of each file.
The -replace operator is used to find and replace the specified text (oldtext) with the new text (newtext). The -replace operator uses regular expressions. Some find and replace values may be misinterpreted as regular expressions.
The modified content is then written back to the file using Set-Content.

This script will iterate through all the files in the specified folder (including subdirectories) with the .txt extension and replace the specified text in each file.

Related Pages Online

Regular Expressions

about Regular Expressions / Escaping Characters - PowerShell
The backslash (\) is used to escape characters so they aren't parsed by the regular expression engine.