Add Content in Powershell - powershell

Question

I need to search through multiple files and underneath specific lines i need to insert lines referenced previously in each respective file. So far i cannot get my script to work at all.
This is what i have so far :
$TextLocation = "M:\test"
$files = get-childitem -filter *.gto -path $TextLocation
Foreach ($file in $files) {
$pagetitle = "DS_PGSEQ-DC:"
$a = Get-Content $file.FullName | Select-String "AssignedToUserID-TZ"
$b = Get-Content $file.FullName | Select-String "EFormID-TZ"
Foreach ($line in $file)
{
if([String]$line -eq "DS_PGSEQ-DC:0001")
{
}
elseif([String]$line -eq $pagetitle)
{
Add-Content $file.FullName ($a -and $b)
}
}
}

Answer 1

There are two common ways for inserting text into a text file:
Process the input file(s) line-by-line, write the output to a temporary file and replace the input file(s) with them temp file afterwards.
for ($file in $files) {
$filename = $file.FullName
Get-Content $filename | % {
if ( $_ -match 'seach pattern' ) {
$_
"new line"
}
} | Out-File $tempfile
MoveItem $tempfile $filename -Force
}
Read the entire content of the file(s), insert the text by using a regular expression replacement, and write the modified content back to the file(s).
for ($file in $files) {
$text = [System.IO.File]::ReadAllText($file.FullName)
$text -replace '.*search pattern.*', "`$0`nnew line" |
Out-File $file.FullName
}

Answer 2

$TextLocation = "M:\test"
$Outputlocation = "M:\test\output"
$files = get-childitem -filter *.gto -path $TextLocation
Foreach ($file in $files) {
$pattern = "\d\d\d[2-9]"
$found=$false
$contains=$false
$lines = Get-Content($file.FullName) |
Foreach-object {
if ($_ -match "AssignedToUserID-TZ") {
$a = $_
}
if ($_ -match "EFormID-TZ") {
$b = $_
}
if ($_ -match "DS_PGSEQ-DC:$pattern") {
if($found -eq $false) {
$found=$true
}
} else {
$found=$false
}
if ($found -eq $true) {
$contains=$true
#Add Lines after the selected pattern
$_
$a
$b
}
if ($found -ne $true) {
$_
}
} | Set-Content($Outputlocation + "\" + $file.Name)
}