newbie, where to find source files 528

iforone

I have to object to the term "modulename" as used above. "Module" often has connotations of a kernel module, or other similar enbreasty (i.e., a part of a larger program). What you're installing with apt-get are Debian packages which can be whole programs, or libraries, or kernel modules, or documentation, or....

Strictly speaking, calling it a module isn't necessarily wrong but can give the wrong impression.

snip

If you want to compile something from source, you need to ensure its dependancies are installed first. The 'build-dep' step gets those packages which are needed to build something. For example, if program foo requires the libbar package at runtime it will require the libbar-dev Debian package at compile time. The 'build-dep' step gets all such dependancies (from the Debian archive) in one step.

No. Just to compile from source.

If you install pre-built binaries with 'apt-get install', the runtime dependancies will be installed automatically so that you can run the program.

To compile something for yourself. You can 'apt-get source' the package and use that to build your own .deb files.

Here's a real world example: I need PHP built with aspell-pspell support but the Debian package doesn't include it. So I 'apt-get build-dep php5' to get all of the compile-time dependancies (pre-built binaries, not source), then 'apt-get source php5' to get PHP itself. I make the necessary edits to the PHP configuration and build it, and am left with a bunch of my own .deb files which contain PHP and its components, but this time with aspell support built-in. Then I can transfer those .debs from the development machine to the production web server and install them with dpkg or put them in a local package archive to apt-get them from myself. Either way, I have .deb packages installed (with all the dependancy checking working properly) but with my customizaiton. I could also customize by getting the source tar file from php.net and building that myself, but then I would have .deb packages, thus no dependancy checking. (Dependancy checking works in both directions. There would be no automated check that PHP's dependancies were installed. And packages depending on PHP wouldn't install easily without a PHP .deb package already installed.)

Compiling from source might also be done to leave out features you don't need, to optimize for a specific processor, etc. Ask Gentoo users why they compile from source! You can do the same thing (with less automation) on Debian.