A Deep Dive into the ELF File Format
Elf Quest
© Photo by erin mckenna on Unsplash
Linux and other Unix-based systems use the ELF file format for executables, object code, and shared libraries. Take a peek inside to learn how an ELF file is organized.
An object file is a black box that you can never really see inside. You can't just open it and read it. We all have some understanding that it contains instructions for the computer, coded in a format that only a computer can understand, but we're used to thinking of compiled program code as something of a mystery. If you take a closer look, however, the structure is not as opaque as you might imagine.
Linux, like most other Unix-like operating systems, stores program code in the Executable and Linkable Format (ELF). ELF superseded the less-flexible a.out format and has been the standard in Linux since 1995 and in FreeBSD [1] since 1998. An ELF object file contains the processor-specific instructions that the CPU actually executes. It also contains other information relating to
- how and where to load the object into memory
- dynamic linking
- any public functions exported (or imported) by the object
- debugging
[...]
Buy this article as PDF
(incl. VAT)
Buy Linux Magazine
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters
Support Our Work
Linux Magazine content is made possible with support from readers like you. Please consider contributing when you’ve found an article to be beneficial.
News
-
Is Linus Torvalds Vibe Coding?
The creator of Linux has added AI into his process for Linux kernel development, and it's more than just for debugging.
-
openKylin 3.0 Released with Expanded AI Integration
The latest release features a pre-installed AI agent to help perform tasks.
-
DigitalOcean Ends Open Source Credits Program
In a change that has surprised many open source developers, DigitalOcean has decided to sunset its Open Source Credits Program.
-
Office 365 Available for Testing on Linux via Bottles
Linux users can now test the official Office 365, thanks to Mirko Brombin's work on Bottles.
-
Dutch Government Turns to Open Source for Digital Sovereignty
Following in the footsteps of other European countries, the Netherlands is looking to increase its sovereign digital infrastructure with open source software.
-
Linux May Soon Work on Snapdragon X2-Based PCs
If you're thinking about buying a Snapdragon X2-based desktop or laptop, Linux may soon be an option.
-
KDE for People Initiative Calls for AI Ban in Plasma
A new community of KDE wants the project to adopt a strict no-AI policy for KDE Plasma.
-
KDE Sets Ambitious Goals for 2026 and Beyond
KDE Connect reveals the goals for the Linux desktop darling, with one of those goals long overdue.
-
It’s Time to Test Fedora 45 Beta
Fedora 45 beta has been released with updated Gnome, KDE Plasma, and kernel.
-
Ubuntu Stonking Stingray Gets Even Rustier
Ubuntu 26.10 has completed its migration to the Rust-based coreutils.