this post was submitted on 17 Sep 2023
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Linux is a family of open source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991 by Linus Torvalds. Linux is typically packaged in a Linux distribution (or distro for short).
Distributions include the Linux kernel and supporting system software and libraries, many of which are provided by the GNU Project. Many Linux distributions use the word "Linux" in their name, but the Free Software Foundation uses the name GNU/Linux to emphasize the importance of GNU software, causing some controversy.
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I've seen the term "hooks" used all the time and have always wondered what the need for them is. I was a Windows user my entire life since childhood and recently rectified that a couple months ago.
Unlearning the Windows paradigm of operating systems has been annoying. So many functional aspects of my machine abstracted away made me have to create an entirely new scaffold for learning technology...
A hook is a mechanism for adding functionality at a certain point in a program's normal flow. As a simple example, imagine a program that works by doing three things in order. It could have hooks that allow the user to add actions before or after any individual steps. Each possible point in the flow is a separate hook. One way to implement it is with a directory for each hook in the program's configuration directory, where executables can be placed; the hook runs each executable in sorted order.
I didn't look up any of this, so it may not be the best explanation, but I hope it is helpful.
Thanks for the explanation! I always wondered why would describe hooks so trivially. I'm still bleaching my brain of the Windows habits I developed from lifs-long usage.
I looked a little more into hooks, and am curious if a patch can kind of be like a hook? Where you create a config file that has symlinks to all the executables like you mentioned? Still a noob when it comes to software creation :D
In the free software world, a patch usually describes a file that lists lines to be added to or removed from another file (or multiple files). The most common use for this is probably with actual source code.
Binary (non-text) patches are also possible, and in Windows a software bug-fix "patch" would likely be mostly binary. In the free software world, it's uncommon to use binary patches for updates; instead the source is patched (either in the main upstream project or by a distribution) and a new binary package is built and published.
I don't really understand how those two questions relate, so I may not be able to give you a good answer. Often a configuration file has a
variable=valuestructure, but it would certainly possible to have a list of file paths in a configuration. However, this might instead be implemented as an actual directory (like~/.config/app/pre-hook.d/) where each executable file in that directory is executed by the "pre" hook in the app. (Configuration directories often work very similarly also.)Whether the paths are symlinks is likely to be irrelevant, as this is more a filesystem level feature that would often be ignored entirely by the application.
I hope this is helpful.