{ "mode": "man", "parameter": "standards", "section": "7", "url": "https://www.chedong.com/phpMan.php/man/standards/7/json", "generated": "2026-06-12T03:17:26Z", "sections": { "NAME": { "content": "standards - C and UNIX Standards\n", "subsections": [] }, "DESCRIPTION": { "content": "The CONFORMING TO section that appears in many manual pages identifies various standards to\nwhich the documented interface conforms. The following list briefly describes these stan‐\ndards.\n\nV7 Version 7 (also known as Seventh Edition) UNIX, released by AT&T/Bell Labs in 1979.\nAfter this point, UNIX systems diverged into two main dialects: BSD and System V.\n\n4.2BSD This is an implementation standard defined by the 4.2 release of the Berkeley Software\nDistribution, released by the University of California at Berkeley. This was the\nfirst Berkeley release that contained a TCP/IP stack and the sockets API. 4.2BSD was\nreleased in 1983.\n\nEarlier major BSD releases included 3BSD (1980), 4BSD (1980), and 4.1BSD (1981).\n\n4.3BSD The successor to 4.2BSD, released in 1986.\n\n4.4BSD The successor to 4.3BSD, released in 1993. This was the last major Berkeley release.\n", "subsections": [ { "name": "System V", "content": "This is an implementation standard defined by AT&T's milestone 1983 release of its\ncommercial System V (five) release. The previous major AT&T release was System III,\nreleased in 1981.\n" }, { "name": "System V release 2 (SVr2)", "content": "This was the next System V release, made in 1985. The SVr2 was formally described in\nthe System V Interface Definition version 1 (SVID 1) published in 1985.\n" }, { "name": "System V release 3 (SVr3)", "content": "This was the successor to SVr2, released in 1986. This release was formally described\nin the System V Interface Definition version 2 (SVID 2).\n" }, { "name": "System V release 4 (SVr4)", "content": "This was the successor to SVr3, released in 1989. This version of System V is de‐\nscribed in the \"Programmer's Reference Manual: Operating System API (Intel proces‐\nsors)\" (Prentice-Hall 1992, ISBN 0-13-951294-2) This release was formally described in\nthe System V Interface Definition version 3 (SVID 3), and is considered the definitive\nSystem V release.\n\nSVID 4 System V Interface Definition version 4, issued in 1995. Available online at\n⟨http://www.sco.com/developers/devspecs/⟩.\n\nC89 This was the first C language standard, ratified by ANSI (American National Standards\nInstitute) in 1989 (X3.159-1989). Sometimes this is known as ANSI C, but since C99 is\nalso an ANSI standard, this term is ambiguous. This standard was also ratified by ISO\n(International Standards Organization) in 1990 (ISO/IEC 9899:1990), and is thus occa‐\nsionally referred to as ISO C90.\n\nC99 This revision of the C language standard was ratified by ISO in 1999 (ISO/IEC\n9899:1999). Available online at ⟨http://www.open-std.org/jtc1/sc22/wg14/www\n/standards⟩.\n\nC11 This revision of the C language standard was ratified by ISO in 2011 (ISO/IEC\n9899:2011).\n\nLFS The Large File Summit specification, completed in 1996. This specification de‐\nfined mechanisms that allowed 32-bit systems to support the use of large files (i.e.,\n64-bit file offsets). See ⟨https://www.opengroup.org/platform/lfs.html⟩.\n" }, { "name": "POSIX.1-1988", "content": "This was the first POSIX standard, ratified by IEEE as IEEE Std 1003.1-1988, and sub‐\nsequently adopted (with minor revisions) as an ISO standard in 1990. The term \"POSIX\"\nwas coined by Richard Stallman.\n" }, { "name": "POSIX.1-1990", "content": "\"Portable Operating System Interface for Computing Environments\". IEEE 1003.1-1990\npart 1, ratified by ISO in 1990 (ISO/IEC 9945-1:1990).\n" }, { "name": "POSIX.2", "content": "IEEE Std 1003.2-1992, describing commands and utilities, ratified by ISO in 1993\n(ISO/IEC 9945-2:1993).\n\nPOSIX.1b (formerly known as POSIX.4)\nIEEE Std 1003.1b-1993, describing real-time facilities for portable operating systems,\nratified by ISO in 1996 (ISO/IEC 9945-1:1996).\n\nPOSIX.1c (formerly known as POSIX.4a)\nIEEE Std 1003.1c-1995, which describes the POSIX threads interfaces.\n" }, { "name": "POSIX.1d", "content": "IEEE Std 1003.1c-1999, which describes additional real-time extensions.\n" }, { "name": "POSIX.1g", "content": "IEEE Std 1003.1g-2000, which describes networking APIs (including sockets).\n" }, { "name": "POSIX.1j", "content": "IEEE Std 1003.1j-2000, which describes advanced real-time extensions.\n" }, { "name": "POSIX.1-1996", "content": "A 1996 revision of POSIX.1 which incorporated POSIX.1b and POSIX.1c.\n\nXPG3 Released in 1989, this was the first release of the X/Open Portability Guide to be\nbased on a POSIX standard (POSIX.1-1988). This multivolume guide was developed by the\nX/Open Group, a multivendor consortium.\n\nXPG4 A revision of the X/Open Portability Guide, released in 1992. This revision incorpo‐\nrated POSIX.2.\n\nXPG4v2 A 1994 revision of XPG4. This is also referred to as Spec 1170, where 1170 referred\nto the number of interfaces defined by this standard.\n" }, { "name": "SUS (SUSv1)", "content": "Single UNIX Specification. This was a repackaging of XPG4v2 and other X/Open stan‐\ndards (X/Open Curses Issue 4 version 2, X/Open Networking Service (XNS) Issue 4).\nSystems conforming to this standard can be branded UNIX 95.\n\nSUSv2 Single UNIX Specification version 2. Sometimes also referred to (incorrectly) as\nXPG5. This standard appeared in 1997. Systems conforming to this standard can be\nbranded UNIX 98. See also ⟨http://www.unix.org/version2/⟩.)\n" }, { "name": "POSIX.1-2001, SUSv3", "content": "This was a 2001 revision and consolidation of the POSIX.1, POSIX.2, and SUS standards\ninto a single document, conducted under the auspices of the Austin Group\n⟨http://www.opengroup.org/austin/⟩. The standard is available online at\n⟨http://www.unix.org/version3/⟩.\n\nThe standard defines two levels of conformance: POSIX conformance, which is a baseline\nset of interfaces required of a conforming system; and XSI Conformance, which addi‐\ntionally mandates a set of interfaces (the \"XSI extension\") which are only optional\nfor POSIX conformance. XSI-conformant systems can be branded UNIX 03.\n\nThe POSIX.1-2001 document is broken into four parts:\n\nXBD: Definitions, terms and concepts, header file specifications.\n\nXSH: Specifications of functions (i.e., system calls and library functions in actual\nimplementations).\n\nXCU: Specifications of commands and utilities (i.e., the area formerly described by\nPOSIX.2).\n\nXRAT: Informative text on the other parts of the standard.\n\nPOSIX.1-2001 is aligned with C99, so that all of the library functions standardized in\nC99 are also standardized in POSIX.1-2001.\n\nThe Single UNIX Specification version 3 (SUSv3) comprises the Base Specifications con‐\ntaining XBD, XSH, XCU, and XRAT as above, plus X/Open Curses Issue 4 version 2 as an\nextra volume that is not in POSIX.1-2001.\n\nTwo Technical Corrigenda (minor fixes and improvements) of the original 2001 standard\nhave occurred: TC1 in 2003 and TC2 in 2004.\n" }, { "name": "POSIX.1-2008, SUSv4", "content": "Work on the next revision of POSIX.1/SUS was completed and ratified in 2008. The\nstandard is available online at ⟨http://www.unix.org/version4/⟩.\n\nThe changes in this revision are not as large as those that occurred for\nPOSIX.1-2001/SUSv3, but a number of new interfaces are added and various details of\nexisting specifications are modified. Many of the interfaces that were optional in\nPOSIX.1-2001 become mandatory in the 2008 revision of the standard. A few interfaces\nthat are present in POSIX.1-2001 are marked as obsolete in POSIX.1-2008, or removed\nfrom the standard altogether.\n\nThe revised standard is structured in the same way as its predecessor. The Single\nUNIX Specification version 4 (SUSv4) comprises the Base Specifications containing XBD,\nXSH, XCU, and XRAT, plus X/Open Curses Issue 7 as an extra volume that is not in\nPOSIX.1-2008.\n\nAgain there are two levels of conformance: the baseline POSIX Conformance, and XSI\nConformance, which mandates an additional set of interfaces beyond those in the base\nspecification.\n\nIn general, where the CONFORMING TO section of a manual page lists POSIX.1-2001, it\ncan be assumed that the interface also conforms to POSIX.1-2008, unless otherwise\nnoted.\n\nTechnical Corrigendum 1 (minor fixes and improvements) of this standard was released\nin 2013.\n\nTechnical Corrigendum 2 of this standard was released in 2016.\n\nFurther information can be found on the Austin Group web site,\n⟨http://www.opengroup.org/austin/⟩.\n" }, { "name": "SUSv4 2016 edition", "content": "This is equivalent to POSIX.1-2008, with the addition of Technical Corrigenda 1 and 2\nand the XCurses specification.\n" }, { "name": "POSIX.1-2017", "content": "This revision of POSIX is technically identical to POSIX.1-2008 with Technical Corri‐\ngenda 1 and 2 applied.\n" }, { "name": "SUSv4 2018 edition", "content": "This is equivalent to POSIX.1-2017, with the addition of the XCurses specification.\n\nThe interfaces documented in POSIX.1/SUS are available as manual pages under sections 0p\n(header files), 1p (commands), and 3p (functions); thus one can write \"man 3p open\".\n" } ] }, "SEE ALSO": { "content": "getconf(1), confstr(3), pathconf(3), sysconf(3), attributes(7), featuretestmacros(7),\nlibc(7), posixoptions(7), systemdatatypes(7)\n", "subsections": [] }, "COLOPHON": { "content": "This page is part of release 5.10 of the Linux man-pages project. A description of the\nproject, information about reporting bugs, and the latest version of this page, can be found\nat https://www.kernel.org/doc/man-pages/.\n\n\n\nLinux 2020-11-01 STANDARDS(7)", "subsections": [] } }, "summary": "standards - C and UNIX Standards", "flags": [], "examples": [], "see_also": [ { "name": "getconf", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/getconf/1/json" }, { "name": "confstr", "section": "3", "url": "https://www.chedong.com/phpMan.php/man/confstr/3/json" }, { "name": "pathconf", "section": "3", "url": "https://www.chedong.com/phpMan.php/man/pathconf/3/json" }, { "name": "sysconf", "section": "3", "url": "https://www.chedong.com/phpMan.php/man/sysconf/3/json" }, { "name": "attributes", "section": "7", "url": "https://www.chedong.com/phpMan.php/man/attributes/7/json" }, { "name": "featuretestmacros", "section": "7", "url": "https://www.chedong.com/phpMan.php/man/featuretestmacros/7/json" }, { "name": "libc", "section": "7", "url": "https://www.chedong.com/phpMan.php/man/libc/7/json" }, { "name": "posixoptions", "section": "7", "url": "https://www.chedong.com/phpMan.php/man/posixoptions/7/json" }, { "name": "systemdatatypes", "section": "7", "url": "https://www.chedong.com/phpMan.php/man/systemdatatypes/7/json" } ] }