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References
- ↑ Ritchie (1993): "Thompson's PDP-7 assembler outdid even DEC's in simplicity; it evaluated expressions and emitted the corresponding bits. There were no libraries, no loader or link editor: the entire source of a program was presented to the assembler, and the output file—with a fixed name—that emerged was directly executable. (This name, a.out, explains a bit of Unix etymology; it is the output of the assembler. Even after the system gained a linker and a means of specifying another name explicitly, it was retained as the default executable result of a compilation.)"
- ↑ Wood, Rupert (8 April 2002). "What to do with a.out". gcc-help (Mailing list). Retrieved 28 April 2007.
- ↑ "A way out for a.out [LWN.net]". lwn.net. Retrieved 12 September 2022.
- ↑ Ritchie, Dennis (3 November 1971). a.out – assembler and link editor output (PDF). Bell Labs . Retrieved 24 November 2006.
- ↑ "a.out page from Section 5 of the unix 8th manual". man.cat-v.org. Retrieved 12 October 2022.
- ↑ Lucas, Michael W. (2019). Absolute FreeBSD : the complete guide to FreeBSD (3rd ed.). San Francisco. p. 408. ISBN 9781593278922.
{{cite book}}: CS1 maint: location missing publisher (link) - ↑ Barlow, Daniel (14 July 1996). "The Linux ELF HOWTO (v1.29)". Archived from the original on 13 July 2004. Retrieved 28 March 2008.
- ↑ Drepper, Ulrich (20 August 2006). "How To Write Shared Libraries" (PDF). 4.0. Section 1.1 (A Little Bit of History). Archived (PDF) from the original on 16 June 2007. Retrieved 20 June 2007.
When introducing shared libraries certain design decisions had to be made to work in the limitations of a.out. (...) For all these reasons and more, Linux converted early on to using ELF (Executable Linkage Format) as the binary format.
{{cite journal}}: Cite journal requires|journal=(help) - ↑ Youngdale, Eric (1 April 1995). "The ELF Object File Format: Introduction". Archived from the original on 10 March 2009. Retrieved 6 May 2012.
(...) it is not impossible to design shared library implementations that work with a.out. The current Linux shared libraries are certainly one example; another example is SunOS-style shared libraries which are currently used by BSD-du-jour. SunOS-style shared libraries contain a lot of the same concepts as ELF shared libraries (...)
- ↑ "BSD Myths". Archived from the original on 17 April 2007. Retrieved 10 April 2007.
There were no pressing reasons to switch earlier. In particular, FreeBSD did not (and does not) have the problems building shared libraries that spurred the Linux conversion from a.out to ELF.
- ↑ "Linux Kernel Finally Deprecating A.out Support". Phoronix. Retrieved 1 September 2020.
- ↑ Petkov, Borislav (5 March 2019). "x86: Deprecate a.out support" . Retrieved 5 March 2019.
Linux supports ELF binaries for ~25 years now. a.out coredumping has bitrotten quite significantly and would need some fixing to get it into shape again but considering how even the toolchains cannot create a.out executables in its default configuration, let's deprecate a.out support and remove it a couple of releases later, instead.
- ↑ Corbet, Jonathan (22 May 2022). "The 5.18 kernel has been released". LWN. Retrieved 22 May 2022.
the last vestiges of a.out support have been removed
- Ritchie, Dennis M. (20–23 April 1993). The Development of the C Language. The Second ACM SIGPLAN History of Programming Languages Conference (HOPL-II). Cambridge, MA: ACM. pp. 201–208. doi:10.1145/154766.155580. ISBN 0-89791-570-4.