History of ELF

	Revision 3 . . October 9, 2001 1:33 am by Dachshund [Added "Extremely Low Frequencies", moved previous info->"Executable and Linkable Format" and added a link.]
	Revision 2 . . October 8, 2001 5:32 pm by Drj [spelling correction. +a.out +coff +man elf]

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Difference (from prior major revision) (no other diffs)

Changed: 1c1

ELF, an acronym for "Executable and Linkable Format", is a common standard in computing for executables? and object code. First published in the [Tool Interface Standard]? and the [System V Application Binary Interface]?, it was quickly accepted among different vendors of UNIX systems.

1. Acronym for "Extremely Low Frequencies", a frequency range for radio transmission in the 3Hz to 3kHz range. ELF is used by the US Navy to communicate with submerged submarines.

Changed: 3,18c3

Today (2001), the ELF format has replaced the proprietary (or sometimes just platform specific) executable formats in the Linux, Solaris, Irix, and some BSD operating systems. The current version number of the official ELF standard is 1.2. Other object code file format are a.out? and COFF?; ELF could be considered a "competitor" to those. ELF file layout Each ELF file is made up by one ELF header, followed by zero or more segments and zero or more sections. The segments contain information that is necessary for runtime execution of the file, while sections contain important data for linking and relocation. Each byte in the entire file is taken by no more than one section at a time, but there can be orphan bytes, which are not covered by a section. In the normal case of a UNIX executable one or more sections are enclosed in one segment. The segments and sections of the file are listed in a program header table and section header table respectivly. On many UNIX systems the command :man elf may provide some more details.

2. Acronym for "Executable and Linkable Format", a common standard in computing for executables? and object code.