Insert Content into Text File in Powershell

How about this:

(gc $fileName) -replace "pattern", "$&`nText To Add" | sc $fileName 

I think that is fairly straight-forward. The only non-obvious thing is the "$&", which refers to what was matched by "pattern". More info: http://www.regular-expressions.info/powershell.html

This problem could be solved by using arrays. A text file is an array of strings. Every element is a line of text.

$FileName = "C:\temp\test.txt" $Patern = "<patern>" # the 2 lines will be added just after this pattern $FileOriginal = Get-Content $FileName <# create empty Array and use it as a modified file... #> $FileModified = @() Foreach ($Line in $FileOriginal) { $FileModified += $Line if ($Line -match $patern) { #Add Lines after the selected pattern $FileModified += 'add text' $FileModified += 'add second line text' } } Set-Content $fileName $FileModified 

I was attempting to do this, but with an XAML textbox. This thread gave me the starting point I needed to make it work.

For anyone else looking to do this:

#Find and replace matched line in textbox $TextBox.Text = ($TextBox.Text) | Foreach-Object { if ($_ -match "pattern") { #Replace matched line $_ -replace "pattern", "Text To Add" } } 

(Get-Content $fileName) | Foreach-Object { if ($_ -match "pattern") { write-output $_" Text To Add" } else{ write-output $_ } } | Set-Content $fileName 

Below script works for inserting a text after a pattern for multiple files in the specified path

$fileNames = Get-ChildItem "C:\Example" -Recurse | select -expand fullname foreach ($FileName in $filenames) { $pattern = "pattern" [System.Collections.ArrayList]$file = Get-Content $FileName $insertafter = @() for ($i=0; $i -lt $file.count; $i++) { if ($file[$i] -match $pattern) { $insertafter += $i+1 #Record the position of the line after this one } } #Now loop the recorded array positions and insert the new text $insertafter | Sort-Object -Descending | ForEach-Object { $file.insert($_, "text inserted after pattern") } Set-Content $FileName $file } 

Solution for an exact match of text in a txt,properties,pf etc file.

$FileName = "C:\Progress\OpenEdge\properties\fathom.properties" $Pattern = "[Fathom]" $FileOriginal = Get-Content $FileName [String[]] $FileModified = @() Foreach ($Line in $FileOriginal) { $FileModified += $Line if ( $Line.Trim() -eq $Pattern ) { #Add Lines after the selected pattern $FileModified += "Autostart=true" } } Set-Content $fileName $FileModified