Question

This seems basic however can’t find or figure out anywhere.

I have a .csv file that I would like to import, change the user column that has different SIDs to the user name that corresponds, then export back to the .csv. I know how to find the SIDtoUser, but I can’t figure out how to do the replace in the .csv. Also some user columns are blank or have “admin” which I need to leave alone.

Current

ComputerName,   TimeStamp,  Message,    User               
hp8440,         8/30/2012,  message1,   admin  
hp8440,         8/30/2012,  message2  
hp8440,         8/30/2012,  message3,   S-1-5-21...1105  
hp8440,         8/30/2012,  message4,   S-1-5-21...1255

Would like it to read

ComputerName,   TimeStamp,  Message,    User  
hp8440,         8/30/2012,  message1,   admin  
hp8440,         8/30/2012,  message2  
hp8440,         8/30/2012,  message3,   user1  
hp8440,         8/30/2012,  message4,   user2

Answer 1

Import-Csv .\sid.csv | ForEach-Object{

    if($_.User -and $_.User -ne 'admin')
    {
        # User is not empty and not admin
        # perform translation and assign the results back to the User column
        # then return the current object back to the pipeline
        $_.User = (New-Object System.Security.Principal.SecurityIdentifier $_.User).Translate([System.Security.Principal.NTAccount]).Value
        $_
    }
    else
    {
        # Ignore empty User or admin 
        # and return the current object back to the pipeline
        $_
    }

} | Export-Csv .\users.csv