757
tar -vczfx123 ought to do it
(imgs.xkcd.com)
img title="I don't know what's worse--the fact that after 15 years of using tar I still can't keep the flags straight, or that after 15 years of technological advancement I'm still mucking with tar flags that were 15 years old when I started."
tar -extract -any -file is easier, auto detect the compression based on filename.
I think GNU tar automatically detects the compression, making
-aunnecessary in that case.And
-z.tar -xf foo.tar.{gz,xz,zstd,...}will work perfectly fine.