Developer's Topics
Chapter 8, ELF object files
----------------------------------------------------------------------------

Chapter 8

ELF object files

This chapter describes the executable and linking format (ELF) of the
object files produced by the C compilation system. The first section,
``Program linking'', focuses on how the format pertains to building
programs. The second section, ``Program execution'', focuses on how the
format pertains to loading programs. See ``Link editing'' in the Programming
Tools Guide for more information.

There are three main types of object files:

   * A relocatable file holds code and data suitable for linking with other
     object files to create an executable or a shared object file.

   * An executable file holds a program suitable for execution; the file
     specifies how exec() creates a program's process image.

   * A shared object file holds code and data suitable for linking in two
     contexts. First, the link editor processes the shared object file with
     other relocatable and shared object files to create another object
     file. Second, the dynamic linker combines it with an executable file
     and other shared objects to create a process image.

Programs manipulate object files with the functions contained in the ELF
access library, libelf. See elf(S) for more information.