System 4 or System IV may refer to:
AIX is a series of proprietary Unix operating systems developed and sold by IBM for several of its computer platforms.
Cygwin is a Unix-like environment and command-line interface for Microsoft Windows. Cygwin's purpose is expressed in its motto: "Get that Linux feeling – on Windows".
GNU Hurd is a collection of microkernel servers written as part of GNU, for the GNU Mach microkernel. It has been under development since 1990 by the GNU Project of the Free Software Foundation, designed as a replacement for the Unix kernel, and released as free software under the GNU General Public License. When the Linux kernel proved to be a viable solution, development of GNU Hurd slowed, at times alternating between stasis and renewed activity and interest.
Multics is an influential early time-sharing operating system based on the concept of a single-level memory. Nathan Gregory writes that Multics "has influenced all modern operating systems since, from microcomputers to mainframes."
An operating system (OS) is system software that manages computer hardware and software resources, and provides common services for computer programs.
The Bourne shell (sh) is a shell command-line interpreter for computer operating systems.
Ultrix is the brand name of Digital Equipment Corporation's (DEC) discontinued native Unix operating systems for the PDP-11, VAX, MicroVAX and DECstations.
System 7 or System/7 may refer to:
The archiver, also known simply as ar, is a Unix utility that maintains groups of files as a single archive file. Today, ar is generally used only to create and update static library files that the link editor or linker uses and for generating .deb packages for the Debian family; it can be used to create archives for any purpose, but has been largely replaced by tar for purposes other than static libraries. An implementation of ar is included as one of the GNU Binutils.
In computing, a hard link is a directory entry that associates a name with a file. Thus, each file must have at least one hard link. Creating additional hard links for a file makes the contents of that file accessible via additional paths. This causes an alias effect: a process can open the file by any one of its paths and change its content. By contrast, a soft link or “shortcut” to a file is not a direct link to the data itself, but rather a reference to a hard link or another soft link.
The inode is a data structure in a Unix-style file system that describes a file-system object such as a file or a directory. Each inode stores the attributes and disk block locations of the object's data. File-system object attributes may include metadata, as well as owner and permission data.
Unix System V is one of the first commercial versions of the Unix operating system. It was originally developed by AT&T and first released in 1983. Four major versions of System V were released, numbered 1, 2, 3, and 4. System V Release 4 (SVR4) was commercially the most successful version, being the result of an effort, marketed as Unix System Unification, which solicited the collaboration of the major Unix vendors. It was the source of several common commercial Unix features. System V is sometimes abbreviated to SysV.
du is a standard Unix program used to estimate file space usage—space used under a particular directory or files on a file system. A Windows commandline version of this program is part of Sysinternals suite by Mark Russinovich.
rm is a basic command on Unix and Unix-like operating systems used to remove objects such as computer files, directories and symbolic links from file systems and also special files such as device nodes, pipes and sockets, similar to the del command in MS-DOS, OS/2, and Microsoft Windows. The command is also available in the EFI shell.
Windows Services for UNIX (SFU) is a discontinued software package produced by Microsoft which provided a Unix environment on Windows NT and some of its immediate successor operating-systems.
In computing, a shebang is the character sequence consisting of the characters number sign and exclamation mark at the beginning of a script. It is also called sharp-exclamation, sha-bang, hashbang, pound-bang, or hash-pling.
The Berkeley Software Distribution or Berkeley Standard Distribution (BSD) is a discontinued operating system based on Research Unix, developed and distributed by the Computer Systems Research Group (CSRG) at the University of California, Berkeley. The term "BSD" commonly refers to its open-source descendants, including FreeBSD, OpenBSD, NetBSD, and DragonFly BSD.
Unix is a family of multitasking, multi-user computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, and others.
A command-line interface (CLI) is a means of interacting with a device or computer program with commands from a user or client, and responses from the device or program, in the form of lines of text. Such access was first provided by computer terminals starting in the mid-1960s. This provided an interactive environment not available with punched cards or other input methods.
NetBSD is a free and open-source Unix operating system based on the Berkeley Software Distribution (BSD). It was the first open-source BSD descendant officially released after 386BSD was forked. It continues to be actively developed and is available for many platforms, including servers, desktops, handheld devices, and embedded systems.