Gists are a feature of git, and a nice way to share snippets of code or short documents. They benefit from being private or public, and can be cloned etc like standard git repositories.
To post a git from the command line there is a tool available called gist, installed with brew:
brew install gist
Then set your git username + password:
git config --global github.user "jbloggs"
git config --global github.password "welcome1"
Then pass gist the content to post, either on stdin or as a file:
gist filetopost.sh
Optionally specify the file type for appropriate syntax/markup :
gist -t md myfile.txt
gist.private - boolean (yes or no) - Determines whether to make a gist private by default
git config --global gist.prviate yes
gist.extension - string - Default extension for gists you create.
git config --global gist.extension md
gist.browse - boolean (yes or no) - Whether to open the gist in your browser after creation. Default: yes