$folder = 'd:\data_files\'
$7za = 'C:\Program Files\7zip\7za.exe'
get-childitem $folder -filter *.gz |
foreach-object { & $7za e $_.FullName "-o$folder" }
or, much shorter
$folder = 'd:\data_files'
$7za = 'C:\Program Files\7zip\7za.exe'
& $7za e $folder\*.gz "-o$folder"
which will process all *.gz files in one go, instead of looping thru them.
I see the command line stuff here: http://www.dotnetperls.com/7-zip-examples which talks about using the "e" command
What I'm not sure is how I'd call the CLI of 7zip in Powershell, get it to unzip those files, and then let the Powershell script do some other stuff with these unzipped files ?