Suppose:

> ipfs2 add Massive1TBFile
added QmXMJ1oewy8hrru1gswxVPHS8kQs3tyjsUXBY33sJTaKeR Massive1TBFile
> ipfs2 daemon &
> ipfs2 cat QmXMJ1oewy8hrru1gswxVPHS8kQs3tyjsUXBY33sJTaKeR
...

As it stands now, the cmd lib may:

• load up the entire file in memory before sending it to the client as a response. (it should start outputing as soon as possible, as is usual with writers.)
• hold the entire thing in memory to pass it through the marshaler (it should either marshal subsections or disable marshaling somehow?)
• test with a large file