Posix

The latest articles related to Posix

FreeVMS – Introduction

FreeVMS is a free software clone of the VMS computer operating system, licensed under the terms of the GNU General Public License. As of 2009, the project is in the early stages of development. The latest version is 0.3.15. It consists of a kernel (planned to be POSIX-compliant) and a DCL command-line interpreter. Adapted from [...]

HeliOS – Introduction

HeliOS was a Unix-like operating system for parallel computers developed and sold by Perihelion Software. It was most commonly used on various Transputer systems, but also supported other architectures. The system provided a micro-kernel that implemented a distributed name space and messaging protocol, through which services were accessed. A POSIX compatibility library enabled the use [...]

Prelink – Introduction

prelink is a free program written by Jakub Jelínek of Red Hat for POSIX-compliant operating systems, principally Linux (because it modifies ELF executables). It is intended to speed up a system by reducing the time a program needs to begin. Actual results have been mixed, but it seems to aid systems with a large number [...]

X/Open – Introduction

X/Open Company, Ltd. was a consortium founded by several European UNIX systems manufacturers in 1984 to identify and promote open standards in the field of information technology. More specifically, the original aim was to define a single specification for operating systems derived from UNIX, to increase the interoperability of applications and reduce the cost of [...]

Symbolic link – Introduction

symbolic link (also ”symlink” or ”soft link”) is a special type of file that contains a reference to another file or directory in the form of an absolute or relative path and that affects pathname resolution. Symbolic links were already present by 1978 in mini-computer operating systems from DEC and Data General’s RDOS. Today they [...]

Ixemul.library – Limitations

The library does not emulate the BSD system API in its entirety. Some of the signals, such as SIGSTOP, are missing. The use of some process control functions, such as fork, cannot be fully implemented due to the Amiga’s lightweight, non-virtual memory system; instead, more lightweight versions, such as vfork, are utilized. The library does [...]

System call – Examples and tools

On Unix, Unix-like and other POSIX-compatible operating systems, popular system calls are open, read, write, close, wait, exec, fork, exit, and kill. Many of today’s operating systems have hundreds of system calls. For example, Linux has 319 different calls, and FreeBSD has almost 500. Tools such as strace and truss allow a process to execute [...]

Cd (command) – Introduction

cd, sometimes also available as chdir (change directory), is a command line command to change the current working directory in operating systems such as Unix, DOS, OS/2, AmigaOS (where if a bare path is given, cd is ”implied”), Windows, and Linux. It is also available for use in shell scripts and batch files. chdir(2) is [...]

Tandem Computers – History

Tandem Computers was founded in 1974 by James Treybig, who had worked up the business plan while at Kleiner & Perkins after leaving Hewlett-Packard. Jimmy pulled together the core group from people at HP: Mike Green, Jim Katzman, and Jack Loustaunou. Their business plan called for systems that were safe from “single-point failures” that were [...]

Application programming interface – Implementations

The POSIX standard defines an API that allows a wide range of common computing functions to be written in a way such that they may operate on many different systems (Mac OS X, and various Berkeley Software Distributions (BSDs) implement this interface); however, making use of this requires re-compiling for each platform. A compatible API, [...]

Richard Stallman – GNU project

Stallman announced the plan for the GNU operating system in September 1983 on several ARPANET mailing lists and USENET. In 1985, Stallman published the GNU Manifesto, which outlined his motivation for creating a free operating system called GNU, which would be compatible with Unix. The name GNU is a recursive acronym for “GNU’s Not Unix.” [...]

Starlink Project – History

From its beginning, the project aimed to cope with the ever-increasing data volumes which astronomers had to handle. A 1982 paper exclaimed that astronomers were returning from observing runs (a week or so of observations at a remote telescope) with more than 10 Gigabits of data on tape; at the end of its life the [...]

Make (software) – Modern versions

Make has gone through a number of rewrites, including a number of from-scratch variants which used the same file format and basic algorithmic principles and also provided a number of their own non-standard enhancements. Some of them are: * BSD make, which is derived from Adam de Boor’s work on a version of make capable [...]

Epoll – Introduction

epoll is a scalable event notification mechanism for Linux, first introduced in Linux 2.5.44 . It is meant to replace the older POSIX select(2) and poll(2) system calls, to achieve better performance in more demanding applications, where the number of watched file descriptors is large (unlike the older system calls, which operate at O(n), epoll [...]









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