General Programming Concepts: Writing and Debugging Programs

System V Application Binary Interface

This topic describes the executable and linking format (ELF) of the object files produced by the C and C++ compilation system.

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 Intro(elf) for more information.

NOTE: Further information is available in the System V Application Binary Interface and processor specific supplements. The processor supplements define a naming convention for ELF constants that have processor ranges specified. Names such as DT_ and PT_ for processor specific extensions incorporate the name of the processor.