Is there a standard location where executables dependencies are stored?

Question

When I list the contents of the bin folders on my system, I often only see the executable files. Some of the executables require additional files such as data and configuration files in order to run. Is there a standard system location where these files are stored in order for the executable to find them?

Answer 1

You don't mention your OS in this question, but I see in a previous question you are using macOS, which BSD-based. Since many applications are designed to operate the same on both Linux and BSD, however, the answer is generally the same.

In general, configuration and data could be stored almost anywhere, but that would be a bad idea, so by convention, there are some standards:

• System-wide configuration files are stored in /etc per the Filesystem Hierarchy Standard. Also see FHS differences between OS X, Linux and FreeBSD, but both Linux and BSD are in full agreement on /etc (and most of the rest of the FHS, as far as I know).

• User configuration has been a bit more undefined until relatively recently, with the XDG Base Directory Specification. Applications that follow that specification will store configuration in the directory specified by the $XDG_CONFIG_HOME variable, or $HOME/.config otherwise.

  Again, that's relatively recently. I also recall from another question that you are using the Fish shell, which is one of the applications that follows this convention.

• Additional data may be stored in several places, but the FHS defines "architecture-independent data" (such as Fish's built-in functions, for example) as being in /usr/share.

• Then there's /var, which holds "variable data files" such as log files, mail spools, etc.

I'm probably missing a few common candidates, and I purposely skipped libraries, which are code rather than "configuration and data." But do scan through the FHS and XDG Base Directory Specification for more info.