Trouble editing text files with powershell Get-Content and Set-Content - powershell

Question

Goal: Update text entry on one line within many files distributed on a server
Summary: As part of an application migration between datacenters the .rdp files on end-user desktops need to be updated to point to the new IP address of their Remote Desktop Server. All the .rdp files reside on Windows servers in a redirected folders SMB share where I have Administrative access.
Powershell experience: minimal. Still trying to wrap my head around the way variables, output and piping work.
Was originally trying to make a single line of powershell code to complete this task but got stuck and had to make script file with the two lines of code below.
-Line 1: Search for all .rdp files in the folder structure and store the full path with file name in a variable. Every file will be checked since the users tend to accidentally change file names, eliminating absolute predictability.
-Line 2: I want to make one pass through all the files to replace only instances of two particular IP addresses with the new address. Then write the changes into the original file.
$Path = ls 'C:\Scripts\Replace-RDP\TESTFILES\' -Include *.rdp -Recurse -Force -ErrorAction SilentlyContinue | foreach fullname
$Path | (Get-Content -Path $Path) -Replace 'IPserver1','newIPserver1' -Replace 'IPserver2','newIPserver2' | Set-Content $Path -Force
Have found most of the solution with Powershell but have a problem with the results. The second line of code when output to the screen changes contents correctly in memory. The content written to file however resulted in the new server IP address being written into ALL rdp files even if the source rdp file's target IP address doesn't match the -Replace criterion.
Text inside a .rdp on the relevant line is:
full address:s:192.168.1.123
changes to:
full address:s:172.16.1.23
Thank you for all assistance in reaching the endpoint. Have spent hours learning from various sites and code snippets.

Answer 1

You need to keep track of each file that you are reading so that you can save changes to that file. Foreach-Object makes this process easy. Inside of the Foreach-Object script block, the current object $_ is the FullName value for each of your files.
$CurrentIP1 = '192\.168\.1\.123'
$CurrentIP2 = '192\.168\.1\.124'
$NewIP1 = '172.16.1.23'
$NewIP2 = '172.16.1.24'
$files = (Get-ChildItem 'C:\Scripts\Replace-RDP\TESTFILES\' -Filter *.rdp -Recurse -Force -File -ErrorAction SilentlyContinue).FullName
$files | Foreach-Object {
if (($contents = Get-Content $_) -match "$CurrentIP1|$CurrentIP2") {
$contents -replace $CurrentIP1,$NewIP1 -replace $CurrentIP2,$NewIP2 |
Set-Content $_
}
}
Note that using the -File switch on Get-ChildItem (alias ls) outputs only files. Since -replace uses regex to do matching, you must backslash escape literal . characters.