The Common Object File Format (COFF) is an object file format that was introduced in Unix System V Release 3, and was later adopted by Microsoft for Windows NT. It was superseded by the more powerful ELF in System V Release 4, but as of 2005, COFF is still used in Windows as Portable Executable. In computer science, object file or object code is an intermediate representation of code generated by a compiler after it processes a source code file. ... Wikibooks has more about this subject: Guide to UNIX Unix or UNIX is a computer operating system originally developed in the 1960s and 1970s by a group of AT&T Bell Labs employees including Ken Thompson, Dennis Ritchie, and Douglas McIlroy. ... The many divergents of System V System V, previously known as AT&T System V, was one of the versions of the Unix computer operating system. ... Microsoft Corporation (NASDAQ: MSFT) (HKSE: 4338) is the worlds largest software company, with 2005 global annual sales of 40 billion US dollars and more than 55,000 employees in 85 countries and regions. ... Windows NT is a family of operating systems produced by Microsoft, and was succeeded by Windows 2000 (still based on Windows NT). ... In computing, the Executable and Linkable Format (ELF) is a common standard for executables and object code. ... The many divergents of System V System V, previously known as AT&T System V, was one of the versions of the Unix computer operating system. ... 2005 is a common year starting on Saturday of the Gregorian calendar. ... The Portable Executable (PE) format is an executable file format used in 32-bit and 64-bit versions of Windows operating systems. ...

The original Unix object file format a.out is a very simple design, and was too limited to effectively handle the additions of SVR3, such as shared libraries. Also, a.out does not define a symbolic debug data format; stabs works by encoding debug info into special symbols in the symbol table. a. ... In computer science, a library is a collection of subprograms used to develop software. ... Debugging is a methodical process of finding and reducing the number of bugs, or defects, in a computer program or a piece of electronic hardware thus making it behave as expected. ... In computer science, a symbol table is a data structure used by a language translator such as a compiler or interpreter, where each symbol in a programs source code is associated with information such as location, type and scope level. ...

COFF's main improvement was the introduction of multiple named sections in the object file. Different object files could have different numbers and types of sections. In addition, a debug data format was defined. Section can be: A cross section (in the common sense or the physics sense) In mathematics: A conic section A section of a fiber bundle or sheaf A Caesarean section In UK law, Section 28 In the fictional Star Trek universe, Section 31 A military unit A section (land) is...

However, the COFF design soon turned out also to be too limited; there was a limit on the maximum number of sections, a limit on the length of section names, and so forth. In addition, the debug info was really only capable of supporting C debugging; for instance, C++ had additional constructs that had no way to be represented, and the debug info was designed to be extensible. IBM solved this in AIX with the XCOFF format, MIPS and others used ECOFF, and GNU tools adopted the workaround of encoding stabs info, which was extensible, into special COFF sections in a technique known as stabs-in-coff. The C Programming Language, Brian Kernighan and Dennis Ritchie, the original edition that served for many years as an informal specification of the language The C programming language is a standardized imperative computer programming language developed in the early 1970s by Ken Thompson and Dennis Ritchie for use on the... C++ (pronounced see plus plus, IPA: /siː pləs pləs/) is a general-purpose computer programming language. ... International Business Machines Corporation (IBM, or colloquially, Big Blue) NYSE: IBM (incorporated June 15, 1911, in operation since 1888) is headquartered in Armonk, NY, USA. The company manufactures and sells computer hardware, software, and services. ... Advanced Interactive eXecutive (AIX) is the brand name of IBMs proprietary UNIX operating system. ... XCOFF, for eXtended COFF, is an improved and expanded version of the COFF object file format defined by IBM and used in AIX. Early versions of the PowerPC Macintosh also supported XCOFF, as did BeOS. XCOFF additions include the use of csects to provide subsection granularity of cross-references, and... MIPS may mean: MIPS architecture, a RISC microprocessor architecture. ... The GNU logo, drawn by Etienne Suvasa The GNU project was announced in September 1983 (and begun in January 1984) by Richard Stallman with the goal of creating a complete, free software operating system. ...

See also

• a.out
• ELF
• PE

a. ... In computing, the Executable and Linkable Format (ELF) is a common standard for executables and object code. ... The Portable Executable (PE) format is an executable file format used in 32-bit and 64-bit versions of Windows operating systems. ...

External links

• DJGPP COFF Spec
• Microsoft Knowledge Base Article
• Microsoft Portable Executable and Common Object File Format Specification
• display symbol table of object, library, or executable file