How to replace multiple strings in a file using PowerShell

Question

One option is to chain the -replace operations together. The ` at the end of each line escapes the newline, causing PowerShell to continue parsing the expression on the next line:

$original_file = 'path\filename.abc'
$destination_file =  'path\filename.abc.new'
(Get-Content $original_file) | Foreach-Object {
    $_ -replace 'something1', 'something1aa' `
       -replace 'something2', 'something2bb' `
       -replace 'something3', 'something3cc' `
       -replace 'something4', 'something4dd' `
       -replace 'something5', 'something5dsf' `
       -replace 'something6', 'something6dfsfds'
    } | Set-Content $destination_file

Another option would be to assign an intermediate variable:

$x = $_ -replace 'something1', 'something1aa'
$x = $x -replace 'something2', 'something2bb'
...
$x

To get the post by George Howarth working properly with more than one replacement you need to remove the break, assign the output to a variable ($line) and then output the variable:

$lookupTable = @{
    'something1' = 'something1aa'
    'something2' = 'something2bb'
    'something3' = 'something3cc'
    'something4' = 'something4dd'
    'something5' = 'something5dsf'
    'something6' = 'something6dfsfds'
}

$original_file = 'path\filename.abc'
$destination_file =  'path\filename.abc.new'

Get-Content -Path $original_file | ForEach-Object {
    $line = $_

    $lookupTable.GetEnumerator() | ForEach-Object {
        if ($line -match $_.Key)
        {
            $line = $line -replace $_.Key, $_.Value
        }
    }
   $line
} | Set-Content -Path $destination_file

With version 3 of PowerShell you can chain the replace calls together:

 (Get-Content $sourceFile) | ForEach-Object {
    $_.replace('something1', 'something1').replace('somethingElse1', 'somethingElse2')
 } | Set-Content $destinationFile

Assuming you can only have one 'something1' or 'something2', etc. per line, you can use a lookup table:

$lookupTable = @{
    'something1' = 'something1aa'
    'something2' = 'something2bb'
    'something3' = 'something3cc'
    'something4' = 'something4dd'
    'something5' = 'something5dsf'
    'something6' = 'something6dfsfds'
}

$original_file = 'path\filename.abc'
$destination_file =  'path\filename.abc.new'

Get-Content -Path $original_file | ForEach-Object {
    $line = $_

    $lookupTable.GetEnumerator() | ForEach-Object {
        if ($line -match $_.Key)
        {
            $line -replace $_.Key, $_.Value
            break
        }
    }
} | Set-Content -Path $destination_file

If you can have more than one of those, just remove the break in the if statement.