7. Compile Source Code

Occasionally, you may find a package that is only available as source code. To use it, you'll need to compile and install it on your system. This lesson will guide you through the common process of how to compile from source code.

Preparing Your System

Before you can compile anything, you need the necessary tools. On Debian-based systems like Ubuntu, you can install them with a single command.

sudo apt install build-essential

The build-essential package installs a suite of software development tools, including the GCC compiler and the make utility, which are essential for compilation.

After installing the tools, extract the contents of the source code package, which is typically a .tar.gz file.

tar -xzvf package.tar.gz

Before proceeding, always check for a README or INSTALL file inside the extracted directory. These files often contain specific instructions or dependencies required for that particular package.

The Standard Build Process

While different developers might use various build systems like cmake, the most traditional method involves a three-step process. Understanding this is fundamental to learning how to build source code.

First, run the configure script. This script checks your system for all the necessary dependencies and libraries the software needs to build and run correctly.

./configure

The ./ prefix tells the shell to execute the script from the current directory. If the script reports any missing dependencies, you must install them before continuing.

Next, run the make command. This command reads a file named Makefile in the directory, which contains a set of rules on how to compile the source code into executable programs.

make

Finally, to install the software onto your system, you would typically run:

sudo make install

This command copies the compiled files to the appropriate system directories, making the software available for use.

A Better Way to Install

While sudo make install works, it has a significant drawback: it doesn't register the software with your system's package manager. This makes it difficult to track, update, or cleanly uninstall the package later.

A much better approach is to use checkinstall. This tool runs the installation process but, instead of copying files directly, it creates a native system package (like a .deb file on Debian/Ubuntu) and installs that.

sudo checkinstall

Using checkinstall integrates the compiled software into your package management system. This means you can easily remove it later using apt or dpkg, just like any other package you installed from the official repositories. For this reason, you should always prefer checkinstall over make install.

To uninstall a package installed with make install, you would navigate back to the source directory and run sudo make uninstall, but this is not always reliable.