Replace different occurences of String with different values in powershell? - regex

Question

I am pretty new to powershell scripting.The scenario is that I have to replace the first occurrence of a string with different value and second occurrence with a different value.
So far, I have this :
$dbS = Select-String $repoPath\AcceptanceTests\sample.config -Pattern([regex]'dbServer = "#DB_SERVER#"')
write-output $dbS[0]
write-output $dbS[1]
This gives the output as :
D:\hg\default\AcceptanceTests\sample.config:5: dbServer = "#DB_SERVER#"
D:\hg\default\AcceptanceTests\sample.config:12: dbServer = "#DB_SERVER#"
I can see that both the occurrences are correct, and this returns a MatchInfo object.Now I need to replace the contents,I tried :
Get-Content $file | ForEach-Object { $_ -replace "dbserver",$dbS[0] } | Set-Content ($file+".tmp")
Remove-Item $file
Rename-Item ($file+".tmp") $file
But this replaces all occurence and that too with the entire path. Please help..

Answer 1

Here is what i have come up with:
$dbs = Select-String .\test.config -pattern([regex]'dbServer = "Test1"')
$file = Get-Content .\test.config
$dbs | % {$file[$_.linenumber-1] = $file[$_.linenumber-1] -replace "Test1", "Test3" }
set-content .\test.config $file
It cycles through all results of Select-String and uses its .LineNumber Property (-1) as array index to replace the text only in that line. Next we just set the content again.
If you want to assign different Values for occurance 1 and 2 you can do this:
#replace first occurance
$file[$dbs[0].LineNumber-1] = $file[$dbs[0].LineNumber-1] -replace "Test1", "Test2"
#replace second occurance
$file[$dbs[1].LineNumber-1] = $file[$dbs[1].LineNumber-1] -replace "Test1", "Test3"
This approach obviously only works if you know how many occurances you will have and which of them you want to replace.