Replace the Data Source and Initial Catalog values of WebConfig.XML

Content of XML file

<Configuration ConfiguredType=”Property” Path=”\Package.Connections[ConnStaging].Properties[ConnectionString]” ValueType=”String”>

<ConfiguredValue>Data Source=localhost;Initial Catalog=Stage;Integrated Security=SSPI; Connection Timeout = 10</ConfiguredValue>

</Configuration>

PARAM(
[String]$DatabaseName='DCTarget',
[String]$XML='c:\webconfig.XML',
[String]$DatabaseServer='DataCenterDB01')
[string]$db = 'Catalog='+ $DatabaseName
[string]$dbs = 'Source='+ $DatabaseServer
(Get-Content $XML) | 
Foreach-Object {
$_ -replace "Catalog=([A-Za-z0-9_]+)", $db -replace "Source=([A-Za-z0-9_]+)", $dbs } | Set-Content $XML

The above code can be used to modify the content of any files or even copy the modified content to new file

$Sourcefile = 'c:\filename.txt'
$desfile =  'c:\Newfilename.txt'
(Get-Content $Sourcefile) | Foreach-Object {
    $_ -replace 'Prashanth', 'Jayaram' `
       -replace 'SQL', 'PowerShell' 
    } | Set-Content $destFile