curl

issues a GET request to substack and prints the body.

$ curl -s http://substack.net

(The -s gets rid of annoying progress output.)

To see just the headers, use -I:

$ curl -I -s http://substack.net

Use -X to set the http verb (POST) and -d to set form parameters:

$ curl -X POST http://localhost:5000 -d title=whatever \
-d date=1421044443 -d body='beep boop!'

Use -H to set header:

$ curl -X POST http://localhost:5000 -d title=whatever \
-d date=1421044443 -d body='beep boop!' \
-H cool:beans