Is there a generic way to set output filename?

New to packer,

When executing packer build, is there a uniform way to specify the output directory or filename without specifying it in a packer file or environment variable?

I am hoping for something like this,

#  user specifies output file name => packer uses name: output.qcow2  .
packer build --out output.qcow2  .  

Or some sort of query sub-command for looking up output filenames like:

#  user queries packer  ==> packer writes name to stdout: output.qcow2
packer inspect  get "output"

I am currently using Packer with a QEMU builder, and I know the output filename
can be set using `‘vm_name``’ property. But it seems like this only applies to QEMU.