The Portable Operating System Interface is a family of standards specified by the IEEE Computer Society for maintaining compatibility between operating systems. POSIX defines the application programming interface, along with command line shells and utility interfaces, for software compatibility with variants of Unix and other operating systems; the name "POSIX" referred to IEEE Std 1003.1-1988, released in 1988. The family of POSIX standards is formally designated as IEEE 1003 and the international standard name is ISO/IEC 9945; the standards emerged from a project that began circa 1985. Richard Stallman suggested the name POSIX to the IEEE instead of former IEEE-IX; the committee found it more pronounceable and memorable, thus adopted it. Unix was selected as the basis for a standard system interface because it was "manufacturer-neutral". However, several major versions of Unix existed—so there was a need to develop a common-denominator system; the POSIX specifications for Unix-like operating systems consisted of a single document for the core programming interface, but grew to 19 separate documents.

The standardized user command line and scripting interface were based on the UNIX System V shell. Many user-level programs and utilities were standardized, along with required program-level services. POSIX defines a standard threading library API, supported by most modern operating systems. In 2008, most parts of POSIX were combined into a single standard; as of 2014, POSIX documentation is divided into two parts: POSIX.1, 2013 Edition: POSIX Base Definitions, System Interfaces, Commands and Utilities POSIX Conformance Testing: A test suite for POSIX accompanies the standard: VSX-PCTS or the VSX POSIX Conformance Test Suite. The development of the POSIX standard takes place in the Austin Group. Before 1997, POSIX comprised several standards: POSIX.1: Core Services Process Creation and Control Signals Floating Point Exceptions Segmentation / Memory Violations Illegal Instructions Bus Errors Timers File and Directory Operations Pipes C Library I/O Port Interface and Control Process Triggers POSIX.1b: Real-time extensions ) Priority Scheduling Real-Time Signals Clocks and Timers Semaphores Message Passing Shared Memory Asynchronous and Synchronous I/O Memory Locking Interface POSIX.1c: Threads extensions Thread Creation and Cleanup Thread Scheduling Thread Synchronization Signal Handling POSIX.2: Shell and Utilities Command Interpreter Utility Programs After 1997, the Austin Group developed the POSIX revisions.

The specifications are known under the name Single UNIX Specification, before they become a POSIX standard when formally approved by the ISO. POSIX.1-2001 equates to the Single UNIX Specification version 3. This standard consisted of: the Base Definitions, Issue 6, the System Interfaces and Headers, Issue 6, the Commands and Utilities, Issue 6. IEEE Std 1003.1-2004 involved a minor update of POSIX.1-2001. It incorporated two minor errata referred to as Technical Corrigenda, its contents are available on the web. Base Specifications, Issue 7 is similar to the current 2017 version. A free online copy may still be available; this standard consists of: the Base Definitions, Issue 7, the System Interfaces and Headers, Issue 7, the Commands and Utilities, Issue 7, the Rationale volume. IEEE Std 1003.1-2017 - IEEE Standard for Information Technology--Portable Operating System Interface Base Specifications, Issue 7 is available from either The Open Group or IEEE and is, as of 22.7.2018, the current standard.

POSIX mandates 512-byte default block sizes for the df and du utilities, reflecting the typical size of blocks on disks. When Richard Stallman and the GNU team were implementing POSIX for the GNU operating system, they objected to this on the grounds that most people think in terms of 1024 byte blocks; the environment variable POSIX_ME_HARDER was introduced to allow the user to force the standards-compliant behaviour. The variable name was changed to POSIXLY_CORRECT; this variable is now used for a number of other behaviour quirks, where "POSIX and common sense disagree". Depending upon the degree of compliance with the standards, one can classify operating systems as or POSIX compatible. Certified products can be found at the IEEE's website; some versions of the following operating systems have been certified to conform to one or more of the various POSIX standards. This means; the following, while not certified as POSIX compatible, comply in large part: Cygwin provides a POSIX-compliant development and run-time environment for Microsoft Windows.

MinGW, a fork of Cygwin, provides a less POSIX-compliant development environment and supports compatible C-programmed applications via Msvcrt, Microsoft's old Visual C runtime library. Microsoft POSIX subsystem, an

2013–14 Georgetown Hoyas men's basketball team

The 2013–14 Georgetown Hoyas men's basketball team represented Georgetown University in the 2013–14 NCAA Division I men's basketball season. They were led by John Thompson III, were members of the Big East Conference, played their home games at the Verizon Center, with one home game at McDonough Gymnasium; the team started the season against the Oregon Ducks in the Armed Forces Classic at Camp Humphreys near Pyeongtaek, South Korea, played in the 2013 Puerto Rico Tip-Off. This was Georgetown's first season as a member of the newly organized Big East Conference, it had been a founding member of the original Big East Conference in the 1979-80 season and had remained a member for 34 seasons. However, that conference's unstable membership and uncertain future and what Georgetown and the conference's other basketball-only members believed to be its focus on college football at the expense of the interests of its basketball programs led Georgetown and six other Big East members to leave the conference after the conclusion of the 2012–13 season.

In 2013 they joined Butler and Xavier in forming a new Big East Conference. One immediate effect of the conference realignment was that for the first time since the 1977-78 season the Hoyas did not play Syracuse, Georgetown's great rival throughout the original Big East Conference's 34-season history. Following the previous season, Georgetown sophomore forward Otto Porter Jr. had left the team for a career in the National Basketball Association after two impressive collegiate years in which he had led the team in all statistical categories, the Hoyas keenly felt his loss. Without any seniors on the team the previous year, Georgetown had lost no players to graduation over the offseason, the only player to transfer from Georgetown, then-freshman center Brandon Bolden, had had no playing time during his only season as a Hoya. Georgetown returned the rest of its veteran players, with senior Markel Starks at point guard. Sophomore guard David Allen made the team as a walk-on for the second straight season, sophomore guard Riyan Williams – the son of former Georgetown great Reggie Williams – walked on and was added to the roster in January 2014, the third time in Georgetown men's basketball history that the son of a former Georgetown player made the team.

Senior guard John Caprio, a walk-on in his first three seasons, made the team as a scholarship player for the first and only time. Junior forward Greg Whittington, Georgetown's second-leading scorer and rebounder of the 2012-13 season before he was suspended for academic reasons at midseason and missed the last 19 games of the year returned, but he had undergone knee surgery over the offseason and began the 2013-14 campaign sidelined while he recovered. Junior center Tyler Adams, sidelined early in his freshman season by heart arrhythmia, spent the season on a medical hardship waiver that allowed him to continue at Georgetown on a scholarship without counting against the team's scholarship total; the Hoyas welcomed two new players for 2013–14. Power forward Reggie Cameron joined the team as its only freshman, but most attention centered around its only other newcomer, junior center Joshua Smith, who joined Georgetown as a transfer from UCLA. In his freshman year at UCLA in 2010 -- 11, Smith averaged 6.3 rebounds per game.

By his sophomore season in 2011–12, however, he had lost the confidence of Bruins head coach Ben Howland, who believed the 6-foot-10 Smith to be overweight and out of shape – Smith arrived for his sophomore season weighing 350 pounds – and had criticized publicly what he saw as immature behavior on Smith's part. After playing in only six games for the Bruins during his junior year in 2012–13, Smith left UCLA in midseason, transferring in January 2013 to Georgetown, where he began taking classes and practicing with the team during the spring 2013 semester; the National Collegiate Athletic Association would have required Smith to sit out two entire semesters before making his Hoya debut, would have granted him only one more year of eligibility, but Georgetown requested a seasons-of-competition waiver from the NCAA, which the NCAA granted, in effect making a controversial decision to give Smith the same status as a redshirt junior and allow him to begin play for the Hoyas with the opening game of the 2013-14 season and with two years of eligibility remaining.

Thompson, who had recruited Smith in high school, expected Smith and his low-post offensive presence to play a key role for the Hoyas and constructed a team that could take advantage of his presence. Thompson told the press that signing Smith was "a big risk – and figuratively" because of his declining performance during his time at UCLA and questions about his commitment to physical fitness and to playing winning basketball, but that the risk was worth it if Smith worked hard and stayed in

Alabama Steeldogs

The Alabama Steeldogs known as the Birmingham Steeldogs, were incorporated in 2000 as one of the charter teams in the AF2, the developmental league of the Arena Football League. Entering their eighth season as of 2007, they were the longest running of many professional football franchises in the city of Birmingham. Management announced that it would not field a team in 2008 but had hopes of returning in 2009, but the team's front office has since been dissolved, with no announcements of further plans, the team is defunct. The team's first head coach was former University of Alabama standout Bobby Humphrey. In October 2005, Ron Selesky of the Arena Football League's Columbus Destroyers, Carolina Cobras and Tampa Bay Storm, as well as the AF2's Albany Conquest and Louisville Fire, was hired as the team's second coach; the team played its home games at the Birmingham Jefferson Convention Complex Arena in downtown Birmingham. The arena was the site of the first AF2 game in 2000, between the Steeldogs and the Tennessee Valley Vipers, based in Huntsville, Alabama.

The team's colors were black and white. The team's name — unique in all of sports — paid tribute to Birmingham's steel industry; the team's logo, depicting a dog with a spiked collar and metal lower jaw, represents "Rusty", the team's mascot. The team's cheerleaders were known as the "Showsteelers." On April 20, 1999, Birmingham's franchise was one of the charter teams in the Xtreme Football League, which soon brokered a deal with the more-established Arena Football League to form the latter's second tier. Christened "Arena Football 2" or "AF2" for short, the new league would play by the same rules patented by its parent organization. After a contest, the team became the "Steeldogs", paying homage to the steel industry that helped grow the city into an industrial giant during the early 20th century. At a press conference on August 12, 1999, the team's name, logo and head coach were all introduced. Humphrey, the University of Alabama's second all-time leading rusher, would be the team's first coach.

The first Steeldogs ownership group, consisting of Charles Felix, David Berkman and Bruce Burge owned the Birmingham Bulls hockey franchise. Both teams were to compete and be headquartered at the Birmingham Jefferson Convention Complex in downtown Birmingham. On January 11, 2000, the Commissioner of the AF2, Mary Ellen Garling announced the league would kick off its inaugural season at the BJCC Arena on March 31, 2000; the Steeldogs first opponent would be the Tennessee Valley Vipers, Birmingham's neighbor 100 miles to the north in Huntsville. The inaugural game was played before 14,831 fans and a regional television audience in the BJCC Arena on March 31, 2000; the game is ranked 3rd in the league's largest regular season crowds. The scoreboard, as is typical in arena football, got quite a workout. Tennessee Valley won the first game in the series, 59-18. Birmingham's first win came one week at the BJCC, as the Steeldogs shut down the Greensboro Prowlers 18-7 in one of the lowest scoring games in the history of Arena Football.

Birmingham would finish the year with a 7-9 final record. In addition to the win over the Prowlers, Birmingham racked up victories over Roanoke, Tallahassee and Tulsa; the Steeldogs’ win over Tallahassee, an 86-74 barnburner, still ranks as the fourth-highest scoring game in AF2 history. By the end of the first season, 71,402 fans had crossed the turnstiles; the second season of Steeldogs football brought the team's second ownership group. Steve and Kathryn Umberger purchased the team on December 13, 2000; the couple purchased the AF2's Jacksonville Tomcats in the same year, but he decided that Birmingham would be his more "hands-on" investment. Humphrey was retained as the team's head coach for a second season; the league expanded nearly twofold in 2001 as 28 teams took the field in 2001. Birmingham opened their season at the CenturyTel Center in Bossier City, La. against the expansion Bossier City BattleWings. Birmingham won a thrilling overtime affair, 63-57, it was the first of three consecutive wins to open the 2001 season.

The Steeldogs finished the regular-season 12-4. Birmingham traveled to Richmond, Virginia to face the Richmond Speed on July 21, 2001. Despite reaching the 60-point plateau, a feat that Coach Humphrey stressed in every game, the Steeldogs collapsed in the fourth quarter and fell 67-60. 2002 was the beginning of years of stability in the executive office. The Umbergers sold the franchise to two local men, both of whom were well-acquainted with Birmingham's professional sports history. Buddy King and Scott Myers, of Hibbett Sports, became the majority and minority owners of the team on January 2, 2002; the two had met when King played with and Myers marketed for the Birmingham Fire of the World League of American Football. The pair was anxious to parlay the Steeldogs’ early success into a third season, they retained Humphrey for a third year. Adopting the motto "One Team, One Goal", Birmingham set out to make a playoff run in their third season. After an early loss at Tulsa, Birmingham rebounded to win eight of their next nine games before dropping three of their next four.

The Steeldogs ended the regular-season with an 11-5 record, good enough to earn a trip to Huntsville to face the Vipers in the first round of the playoffs at the Von Braun Center in Huntsville. There the'Dogs cast off three years of frustration at the hands of their fiercest rival, dominating Tennessee Valley in a 65-51 victory. Secondary to the outcome of the game was the fact that the Steeldogs had now earned themselves a trip to Tulsa, for a second-round match-up against the top-ranked team in AF2. On August 10, 2002 Birmingham pulled off the