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 ELF superseded the less-flexible a.out format and has been the standard in Linux since 1995 and in FreeBSD [1] since 1998.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
US / Canada
UK / Australia
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
-
Red Hat Releases RHEL 10 Early
Red Hat quietly rolled out the official release of RHEL 10.0 a bit early.
-
openSUSE Joins End of 10
openSUSE has decided to not only join the End of 10 movement but it also will no longer support the Deepin Desktop Environment.
-
New Version of Flatpak Released
Flatpak 1.16.1 is now available as the latest, stable version with various improvements.
-
IBM Announces Powerhouse Linux Server
IBM has unleashed a seriously powerful Linux server with the LinuxONE Emperor 5.
-
Plasma Ends LTS Releases
The KDE Plasma development team is doing away with the LTS releases for a good reason.
-
Arch Linux Available for Windows Subsystem for Linux
If you've ever wanted to use a rolling release distribution with WSL, now's your chance.
-
System76 Releases COSMIC Alpha 7
With scores of bug fixes and a really cool workspaces feature, COSMIC is looking to soon migrate from alpha to beta.
-
OpenMandriva Lx 6.0 Available for Installation
The latest release of OpenMandriva has arrived with a new kernel, an updated Plasma desktop, and a server edition.
-
TrueNAS 25.04 Arrives with Thousands of Changes
One of the most popular Linux-based NAS solutions has rolled out the latest edition, based on Ubuntu 25.04.
-
Fedora 42 Available with Two New Spins
The latest release from the Fedora Project includes the usual updates, a new kernel, an official KDE Plasma spin, and a new System76 spin.