Can you issue pull requests from the command line on GitHub?

In addition of github/hub, which acts as a proxy to Git, you now (February 2020) have cli/cli:

See "Supercharge your command line experience: GitHub CLI is now in beta"

Create a pull request

Create a branch, make several commits to fix the bug described in the issue, and use gh to create a pull request to share your contribution.

By using GitHub CLI to create pull requests, it also automatically creates a fork when you don’t already have one, and it pushes your branch and creates your pull request to get your change merged.

And in April 2020: "GitHub CLI now supports autofilling pull requests and custom configuration"

GitHub CLI 0.7 is out with several of the most highly requested enhancements from the feedback our beta users have provided.
Since the last minor release, 0.6, there are three main features:

• Configure gh to use your preferred editor with gh config set editor [editor].
• Configure gh to default to SSH with gh config set git_protocol ssh.
  The default Git protocol is HTTPS.
• Autofill the title and body of a pull request from your commits with gh pr create --fill.

So:

gh pr create --fill

I'm using simple alias to create pull request,

alias pr='open -n -a "Google Chrome" --args "https://github.com/user/repo/compare/pre-master...nawarkhede:$(git_current_branch)\?expand\=1"'

You can install github official CLI to create PR and do other sort of things.

To setup:

gh auth login

To create PR:

gh pr create

To merge:

gh pr merge

Yes. You can install the hub CLI util.
On MACOS: brew install hub

You need to have one time GitHub token for login.

User -> Dev settings -> Personal tokens -> Generate
(See: https://github.com/settings/tokens)

git checkout -b mybranch
hub pull-request -b master -h mybranch

#user:     your_user_name
#password: your_git_token