Hello, I'm a bit new to advanced linux and programming stuffs... Can someone explain me why compiling exists and what this process does and how to do it in the principals situations (I've heard that you can use the "makepkg" command). Thx to everyone who replied.
Compiling code converts it from human readable source code into optimized machine code which the processor understands how to execute. For a lot of software you can just unpack the source code, run ./configure, run 'make', and then 'make install'. This can vary a lot and is a simplified explanation, but it's a start...
Open-source software is distributed primarily as source code in a human-readable programming language. Computers can't actually read these programming languages directly; they need to be translated into the machine language of their CPU (such as x86_64). For some languages, like Python, code can be "interpreted" on the fly; for others, like C, programs must be "compiled" into a separate file format. Additionally, most programs consist of multiple files that need to be compiled and linked together, and installed in certain folders on your system, so the compiler and additional tools work to automate that process.
Most users of Linux rarely if ever have to compile anything, because the developers of Linux distros, and some third parties like Flathub, curate collections of (mostly) open-source software that has already been compiled and packaged into formats that are easy to install and uninstall. As part of this process, they usually add some metadata and/or scripts that can automate compiling and packaging, so it only requires a single command (makepkg on Arch, dpkg-buildpackage on Debian.) However, some newer or more obscure software may not be packaged by your distribution or any third-party repo.
How to compile depends on the program, its programming language and what tools the developers prefer to use to compile it. Usually the README file included with source code explains how to compile the software. The most common process uses the commands
./configure; make; sudo make install
after installing all of the program's dependencies and cd-ing to the source code directory. Other programs might include the metadata needed for something like makepkg to work, be written in an interpreted language and thus require no compilation, or use a different toolchain, like CMake.Compiling is when you convert your human-readable programming language to binary machine code.
makepkg is an Arch-exclusive command that ensures that your apps are built properly in any other Arch-based devices. Usually, all packages are compiled on a powerful machine in some server, and you just have to download the binaries.
But in some cases, they don't compile apps, or, their process may have delayed, so you can manually compile those apps on your device - that is called building from the source. From what I know, you can't run makepkg on other Linuces (can we? I've never used Arch in depth).
About .deb and .rpm, those are a type of packaging format - in reality, they're just archives. Think of them as .exe and .msi equivalents. It contains the pre-built app, as well as the repository link, which makes it convenient if you want to upgrade that app in the future.
humm.. ok, and for example when you have the binaries of a file you have to compile it a last time, no? That's my experience with aur, when you get the bin, you have to makepkg a other time
The Arch Linux makepkg is a bash script with description
make packages compatible for use with pacman
Some packages of AUR are not about compiling but fetching the binary (sometimes converting it from deb) and then prepare it for you so you can install it. So when you use AUR to install a binary package instead of compiling there is really no compiling involved afair.
In that case makepkg isn't compiling anything, it's just packaging the existing binaries so that they can be more easily installed and recognized by your package manager.
like linking all the files and make a clean package? So makepkg does everything from the start to end of the compiling process
Yeah, basically. makepkg automates the process of creating an Arch package, and while usually that involves compiling source code, sometimes it just means converting proprietary software that has already been compiled into a different format.
Some software is brand new and not yet packaged as software packages. And for already existing software Linux distributions will have to make choices as not everything can be included and maintained. Now if a developer creates new software, and things are not packaged yet (With Debian for Debian stable this can take a really long time) it can be comfortable for the developer to provide just instructions about how to compile the software so users can run the software, while the maintainer does not have to bother about packaging.
So it's a bit like taking all the useful packages and mix it up in a clean package? And are .deb .rpm... packages made like that?
Yes, indeed. If you would want to you can re-compile Debian deb packages from Debian sources. To give you an idea : https://wiki.debian.org/apt-src There's also Gentoo Linux which has a history of compiling software. Years ago that was interesting because of flags for compiling, make the resulting software optimized for certain CPU models.