export TANK_KEY="my tank key"
tank GET /bags
cat | tank PUT /bags/myNewBag Content-Type:'application/vnd.tiddlyweb+json
{"policy":{}}
^D
tank PUT /bags/myNewBag/tiddlers/app Content-Type:'text/html' < app.html
You might need to remove Accept:text/plain
from the last line for some uses, not sure.
More at http://httpie.org