how to install a github pull-request? (youtube-dl PR)

**TheFu** · August 22nd, 2020

github is a git repo service. git is a DVCS.

From the manpage:

Code:

DESCRIPTION
       Git is a fast, scalable, distributed revision control system with an unusually
       rich command set that provides both high-level operations and full access to
       internals.

The git manpage points out that there is a command - gittutorial

Code:

       See gittutorial(7) to get started, then see giteveryday(7) for a useful
       minimum set of commands. The Git User’s Manual[1] has a more in-depth
       introduction.

git is used by developers to keep track of changes, reasons for changes, and branch software versions. It is how most F/LOSS software teams work together. There are other DVCS, but none are as popular. There are other VCS (not distributed) which have been used over the decades too. cvs, svn, rcs, sccs are examples of the F/LOSS versions. There have been and still are many commercial VCS - I've used StarTeam and MS-SourceSafe in a few companies. Oddly, MS-SourceSafe had corruption problems, which defeats the reason to use a VCS. At home, I've used rcs and git over the decades - even on software that only I work. VCS are great for teams, but just as important for individual programmers. rcs has saved me from huge mistakes at least once a year before I switched to git.

But this isn't a class on any specific VCS. There are lots of those already on youtube. When I first needed to learn git, I watched a video presentation by Randall Schwartz that he gave at Google. That 50 minutes or so explained stuff that isn't intuitively clear to outsiders.

All git repos are the same. It is simply a social agreement between developers on the team which repo will be "the repo" for their project. By cloning the youtube-dl repo, you've got all the code, all the changes, since the beginning, on your local machine.

You can modify that code and use it for your nefarious purposes and as long as you don't share it, nobody would know. Some code has specific license requirements (AGPL) that mandate you share changes with the community. That's called a "pull" request where you make your repo available to the upstream and send the maintainer of that repo a link so she can "pull" your code. Not all licenses require this mandatory sharing and sometimes the requirement to share only happens when you start sharing the code elsewhere (GPL and LGPL). Some licenses don't require any sharing at all - MIT, Perl, BSD, Apache, and a few others. They just require that credit for any coder before you is given. That's why iOS from Apple and Roku devices isn't Open Source. They use BSD code in those devices. TiVo uses Linux, so they have to share their code. Same for most Linux-based routers. Cisco, Linksys, TP-link, D-Link, Ubiquiti, Microtek, all have to share their code for the products based on GPL and LGPL libraries. A few of them were sued in court so they would comply.

Probably more than you cared to know. Software licenses matter to all of us who use Ubuntu. It is because of the GPL that we get it and most Linux software for minimal/$0 cost. There are some fine lines that only Oracle's lawyers seem to have found which allow charges for GPL software.