Specifies the type of archive.
-t{archive_type}
If -t{archive_type} switch is not specified, 7-Zip uses extension of archive filename to detect the type of archive. If you create new archive, -t{archive_type} switch is not specified and there is no extension of archive, 7-Zip will create .7z archive.
When you extract archive of some types that contains another archive without compression (for example, MBR in VHD), 7-Zip can open both levels in one step. If you want to open/extract just top level archive, use -t* switch.
Note: gzip or bzip2 formats support only one file per archive. If you want to compress more than one file to these formats, create a tar archive first, and then compress it with your selected format.
7z a -tzip archive.zip *.txt
adds all *.txt files from current directory to zip archive archive.zip.
7z t -t7z.split archive.7z.001
tests all files in archive.7z.001. It also checks that archive is multivolume .7z archive.
7z x -tiso archive.iso
extracts files from archive.iso open as ISO archive.
7z x -tudf archive.iso
extracts files from archive.iso open as UDF archive.
a (Add), d (Delete), e (Extract), l (List), t (Test), u (Update), x (Extract with full paths)