Add new line to Powershell command output

Question

I run the following code using powershell to get a list of add/remove programs from the registry:

gci -path hklm:\software\microsoft\windows\currentversion\uninstall | ForEach-Object -Process { write-output $_.GetValue("DisplayName") } | out-file addrem.txt

I want the list to be separated by newlines per each program. I've tried:

gci -path hklm:\software\microsoft\windows\currentversion\uninstall | ForEach-Object -Process { write-output $_.GetValue("DisplayName") `n } | out-file test.txt

gci -path hklm:\software\microsoft\windows\currentversion\uninstall | ForEach {$_.GetValue("DisplayName") } | write-host -Separator `n

gci -path hklm:\software\microsoft\windows\currentversion\uninstall | ForEach-Object -Process { $_.GetValue("DisplayName") } | foreach ($_) { echo $_ `n }

But all result in weird formatting when output to console, and with three square characters after each line when output to file.

I tried Format-List, Format-Table, and Format-Wide with no luck.

Originally, I thought something like this would work:

gci -path hklm:\software\microsoft\windows\currentversion\uninstall | ForEach-Object -Process { "$_.GetValue("DisplayName") `n" }

But that just gave me an error...

Answer 1

Give this a try:

PS> $nl = [Environment]::NewLine
PS> gci hklm:\software\microsoft\windows\currentversion\uninstall | 
        ForEach { $_.GetValue("DisplayName") } | Where {$_} | Sort |
        Foreach {"$_$nl"} | Out-File addrem.txt -Enc ascii

Yields the following text in my addrem.txt file:

Adobe AIR

Adobe Flash Player 10 ActiveX

...

Note: on my system, GetValue("DisplayName") returns null for some entries so I filter those out. BTW you were close with this:

ForEach-Object -Process { "$_.GetValue("DisplayName") `n" }

Except that within a string, if you need to access a property of a variable ie "evaluate an expression", then you need to use subexpression syntax like so:

Foreach-Object -Process { "$($_.GetValue('DisplayName'))`r`n" }

Essentially within a double quoted string PowerShell will expand variables like $_ but it won't evaluate expressions unless you put the expression within a subexpression using this syntax $(<multiple statements can go in here>).

Answer 2

I think you had the correct idea with your last example. You only got an error because you were trying to put quotes inside an already quoted string. This will fix it:

gci -path hklm:\software\microsoft\windows\currentversion\uninstall | ForEach-Object -Process { write-output ($_.GetValue("DisplayName") + "`n") }

Edit: Keith's $() operator actually creates a better syntax (I always forget about this one). You can also escape quotes inside quotes as so:

gci -path hklm:\software\microsoft\windows\currentversion\uninstall | ForEach-Object -Process { write-output "$($_.GetValue(`"DisplayName`"))`n" }

Answer 3

Or, just set the output field separator to double newlines, and then make sure you get a string when you send it to file:

$OFS = "`r`n`r`n"
"$( gci -path hklm:\software\microsoft\windows\currentversion\uninstall | 
    ForEach-Object -Process { write-output $_.GetValue('DisplayName') } )" | 
 out-file addrem.txt

Answer 4

Ultimately, what you're trying to do with the EXTRA blank lines between each one is a little confusing :)

I think what you really want to do is use get-itemproperty. You'll get errors when values are missing, but you can suppress them with -ErrorAction 0 or just leave them as reminders. Because the Registry provider returns extra properties, you'll want to stick in a Select-Object that uses the same properties as the Get-Properties.

Then if you want each property on a line with a blank line between, use Format-List (otherwise, use Format-Table to get one per line).

gci -path hklm:\software\microsoft\windows\currentversion\uninstall |
gp -Name DisplayName, InstallDate | 
select DisplayName, InstallDate | 
fl | out-file addrem.txt