The Preferred Executable Format is a
file format
A file format is a Computer standard, standard way that information is encoded for storage in a computer file. It specifies how bits are used to encode information in a digital storage medium. File formats may be either proprietary format, pr ...
that specifies the format of
executable
In computer science, executable code, an executable file, or an executable program, sometimes simply referred to as an executable or binary, causes a computer "to perform indicated tasks according to encoded instruction (computer science), in ...
files and other
object code
In computing, object code or object module is the product of an assembler or compiler
In computing, a compiler is a computer program that Translator (computing), translates computer code written in one programming language (the ''source'' ...
. PEF executables are also called
Code Fragment Manager files (CFM).
PEF was developed by
Apple Computer for use in its
classic Mac OS
Mac OS (originally System Software; retronym: Classic Mac OS) is the series of operating systems developed for the Mac (computer), Macintosh family of personal computers by Apple Computer, Inc. from 1984 to 2001, starting with System 1 and end ...
operating system
An operating system (OS) is system software that manages computer hardware and software resources, and provides common daemon (computing), services for computer programs.
Time-sharing operating systems scheduler (computing), schedule tasks for ...
. It was optimised for
RISC
In electronics and computer science, a reduced instruction set computer (RISC) is a computer architecture designed to simplify the individual instructions given to the computer to accomplish tasks. Compared to the instructions given to a comp ...
processors. In
macOS
macOS, previously OS X and originally Mac OS X, is a Unix, Unix-based operating system developed and marketed by Apple Inc., Apple since 2001. It is the current operating system for Apple's Mac (computer), Mac computers. With ...
, the
Mach-O file format is the native
executable
In computer science, executable code, an executable file, or an executable program, sometimes simply referred to as an executable or binary, causes a computer "to perform indicated tasks according to encoded instruction (computer science), in ...
format. However, PEF was still supported on
PowerPC
PowerPC (with the backronym Performance Optimization With Enhanced RISC – Performance Computing, sometimes abbreviated as PPC) is a reduced instruction set computer (RISC) instruction set architecture (ISA) created by the 1991 Apple Inc., App ...
-based Macintoshes running Mac OS X and was used by some
Carbon
Carbon () is a chemical element; it has chemical symbol, symbol C and atomic number 6. It is nonmetallic and tetravalence, tetravalent—meaning that its atoms are able to form up to four covalent bonds due to its valence shell exhibiting 4 ...
applications ported from earlier versions for classic Mac OS, so that the same binary could be run on classic Mac OS and Mac OS X.
BeOS on PowerPC systems also uses PEF, although
x86 systems do not.
See also
*
Comparison of executable file formats
This is a comparison of binary executable file formats which, once loaded by a suitable executable loader, can be directly executed by the CPU rather than being interpreted by software. In addition to the binary application code, the executables ...
*
Fat binary
External links
PEF Structure- documentation at developer.apple.com via web.archive.org
Mac OS Runtime Architectures For System 7 Through Mac OS 9- PDF from developer.apple.com (see chapter 8, PEF Structure)
- description of what is in a PEF file, such as allowed sections the string table.
{{Mac-software-stub
Executable file formats
Apple Inc. software