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PWD Great Lakes Water Main Installation (14058449987)
In Unix-like and some other operating systems, the pwd command (''print working directory'') writes the full pathname of the current working directory to the standard output. Implementations Multics had a pwd command (which was a short name of the print_wdir command) from which the Unix pwd command originated. The command is a shell builtin in most Unix shells such as Bourne shell, ash, bash, ksh, and zsh. It can be implemented easily with the POSIX C functions getcwd() or getwd(). It is also available in the operating systems SpartaDOS X, PANOS, and KolibriOS. The equivalent on DOS (COMMAND.COM) and Microsoft Windows (cmd.exe) is the cd command with no arguments. Windows PowerShell provides the equivalent Get-Location cmdlet with the standard aliases gl and pwd. On Windows CE 5.0, the cmd.exe ''Command Processor Shell'' includes the pwd command. as found on Unix systems is part of the X/Open Portability Guide since issue 2 of 1987. It was inherited into the first vers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AT&T Bell Laboratories
Nokia Bell Labs, originally named Bell Telephone Laboratories (1925–1984), then AT&T Bell Laboratories (1984–1996) and Bell Labs Innovations (1996–2007), is an American industrial research and scientific development company owned by multinational company Nokia. With headquarters located in Murray Hill, New Jersey, the company operates several laboratories in the United States and around the world. Researchers working at Bell Laboratories are credited with the development of radio astronomy, the transistor, the laser, the photovoltaic cell, the charge-coupled device (CCD), information theory, the Unix operating system, and the programming languages B, C, C++, S, SNOBOL, AWK, AMPL, and others. Nine Nobel Prizes have been awarded for work completed at Bell Laboratories. Bell Labs had its origin in the complex corporate organization of the Bell System telephone conglomerate. In the late 19th century, the laboratory began as the Western Electric Engineering Department, l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GPLv3+
The GNU General Public License (GNU GPL or simply GPL) is a series of widely used free software licenses that guarantee end users the four freedoms to run, study, share, and modify the software. The license was the first copyleft for general use and was originally written by the founder of the Free Software Foundation (FSF), Richard Stallman, for the GNU Project. The license grants the recipients of a computer program the rights of the Free Software Definition. These GPL series are all copyleft licenses, which means that any derivative work must be distributed under the same or equivalent license terms. It is more restrictive than the Lesser General Public License and even further distinct from the more widely used permissive software licenses BSD, MIT, and Apache. Historically, the GPL license family has been one of the most popular software licenses in the free and open-source software domain. Prominent free software programs licensed under the GPL include the Linux kernel an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Korn Shell
KornShell (ksh) is a Unix shell which was developed by David Korn at Bell Labs in the early 1980s and announced at USENIX on July 14, 1983. The initial development was based on Bourne shell source code. Other early contributors were Bell Labs developers Mike Veach and Pat Sullivan, who wrote the Emacs and vi-style line editing modes' code, respectively. KornShell is backward-compatible with the Bourne shell and includes many features of the C shell, inspired by the requests of Bell Labs users. Features KornShell complies with POSIX.2, Shell and Utilities, Command Interpreter (IEEE Std 1003.2-1992.) Major differences between KornShell and the traditional Bourne shell include: * job control, command aliasing, and command history designed after the corresponding C shell features; job control was added to the Bourne Shell in 1989 * a choice of three command line editing styles based on vi, Emacs, and Gosling Emacs * associative arrays and built-in floating-point arithmeti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bash (Unix Shell)
Bash is a Unix shell and command language written by Brian Fox for the GNU Project as a free software replacement for the Bourne shell. First released in 1989, it has been used as the default login shell for most Linux distributions. Bash was one of the first programs Linus Torvalds ported to Linux, alongside GCC. A version is also available for Windows 10 and Windows 11 via the Windows Subsystem for Linux. It is also the default user shell in Solaris 11. Bash was also the default shell in versions of Apple macOS from 10.3 (originally, the default shell was tcsh) to the 2019 release of macOS Catalina, which changed the default shell to zsh, although Bash remains available as an alternative shell. Bash is a command processor that typically runs in a text window where the user types commands that cause actions. Bash can also read and execute commands from a file, called a shell script. Like most Unix shells, it supports filename globbing (wildcard matching), piping, here docu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Almquist Shell
Almquist shell (also known as A Shell, ash and sh) is a lightweight Unix shell originally written by Kenneth Almquist in the late 1980s. Initially a clone of the System V.4 variant of the Bourne shell, it replaced the original Bourne shell in the BSD versions of Unix released in the early 1990s. History ash was first released via a posting to the Usenet news group, approved and moderated by Rich Salz on 30 May 1989. It was described as "a reimplementation of the System V shell ithmost features of that shell, plus some additions". Fast, small, and virtually compatible with the POSIX standard's specification of the Unix shell, ash did not provide line editing or command history mechanisms, because Almquist felt that such functionality should be moved into the terminal driver. However, current variants support it. The following is extracted from the ash package information from Slackware v14: Myriad forks have been produced from the original ash release. These derivatives of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bourne Shell
The Bourne shell (sh) is a Shell (computing), shell Command-line interface#Command-line interpreter, command-line interpreter for computer operating systems. The Bourne shell was the default Unix shell, shell for Version 7 Unix. Unix-like systems continue to have /bin/sh—which will be the Bourne shell, or a symbolic link or hard link to a compatible shell—even when other shells are used by most users. Developed by Stephen R. Bourne, Stephen Bourne at Bell Labs, it was a replacement for the Thompson shell, whose executable file had the same name—sh. It was released in 1979 in the Version 7 Unix release distributed to colleges and universities. Although it is used as an interactive command interpreter, it was also intended as a scripting language and contains most of the features that are commonly considered to produce structured programs. It gained popularity with the publication of ''The Unix Programming Environment'' by Brian Kernighan and Rob Pike—the first commercial ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unix Shell
A Unix shell is a command-line Interpreter (computing), interpreter or shell (computing), shell that provides a command line user interface for Unix-like operating systems. The shell is both an interactive command language and a scripting language, and is used by the operating system to control the execution of the system using shell scripts. Users typically interact with a Unix shell using a terminal emulator; however, direct operation via serial hardware connections or Secure Shell are common for server systems. All Unix shells provide filename Wildcard character, wildcarding, Pipeline (Unix), piping, here documents, command substitution, Variable (programming), variables and control flow, control structures for Conditional (programming), condition-testing and iteration. Concept Generally, a ''shell'' is a program that executes other programs in response to text commands. A sophisticated shell can also change the environment in which other programs execute by passing environm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shell Builtin
In computing, a shell builtin is a command or a function, called from a shell, that is executed directly in the shell itself, instead of an external executable program which the shell would load and execute. Shell builtins work significantly faster than external programs, because there is no program loading overhead. However, their code is inherently present in the shell, and thus modifying or updating them requires modifications to the shell. Therefore, shell builtins are usually used for simple, almost trivial, functions, such as text output. Because of the nature of some operating systems, some functions of the systems must necessarily be implemented as shell builtins. The most notable example is the cd command, which changes the working directory of the shell. Since each executable program runs in a separate process, and working directories are specific to each process, loading cd as an external program would not affect the working directory of the shell that loaded it. Examp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bell Labs
Nokia Bell Labs, originally named Bell Telephone Laboratories (1925–1984), then AT&T Bell Laboratories (1984–1996) and Bell Labs Innovations (1996–2007), is an American industrial research and scientific development company owned by multinational company Nokia. With headquarters located in Murray Hill, New Jersey, the company operates several laboratories in the United States and around the world. Researchers working at Bell Laboratories are credited with the development of radio astronomy, the transistor, the laser, the photovoltaic cell, the charge-coupled device (CCD), information theory, the Unix operating system, and the programming languages B, C, C++, S, SNOBOL, AWK, AMPL, and others. Nine Nobel Prizes have been awarded for work completed at Bell Laboratories. Bell Labs had its origin in the complex corporate organization of the Bell System telephone conglomerate. In the late 19th century, the laboratory began as the Western Electric Engineering Department, l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Standard Output
In computer programming, standard streams are interconnected input and output communication channels between a computer program and its environment when it begins execution. The three input/output (I/O) connections are called standard input (stdin), standard output (stdout) and standard error (stderr). Originally I/O happened via a physically connected system console (input via keyboard, output via monitor), but standard streams abstract this. When a command is executed via an interactive shell, the streams are typically connected to the text terminal on which the shell is running, but can be changed with redirection or a pipeline. More generally, a child process inherits the standard streams of its parent process. Application Users generally know standard streams as input and output channels that handle data coming from an input device, or that write data from the application. The data may be text with any encoding, or binary data. In many modern systems, the standard error str ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Working Directory
In computing, the working directory of a process is a directory of a hierarchical file system, if any, dynamically associated with each process. It is sometimes called the current working directory (CWD), e.g. the BSD getcwd function, or just current directory. When the process refers to a file using a simple file name or relative path (as opposed to a file designated by a full path from a root directory), the reference is interpreted relative to the working directory of the process. So for example a process with working directory /rabbit-shoes that asks to create the file foo.txt will end up creating the file /rabbit-shoes/foo.txt. In operating systems In most computer file systems, every directory has an entry (usually named ".") which points to the directory itself. In most DOS and UNIX command shells, as well as in the Microsoft Windows command line interpreters cmd.exe and Windows PowerShell, the working directory can be changed by using the CD or CHDIR commands. In Unix s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Path (computing)
A path is a string of characters used to uniquely identify a location in a directory structure. It is composed by following the directory tree hierarchy in which components, separated by a delimiting character, represent each directory. The delimiting character is most commonly the slash ("/"), the backslash character ("\"), or colon (":"), though some operating systems may use a different delimiter. Paths are used extensively in computer science to represent the directory/file relationships common in modern operating systems and are essential in the construction of Uniform Resource Locators (URLs). Resources can be represented by either ''absolute'' or ''relative'' paths. History Multics first introduced a hierarchical file system with directories (separated by ">") in the mid-1960s. Around 1970, Unix introduced the slash character ("/") as its directory separator. In 1981, the first version of Microsoft DOS was released. MS-DOS 1.0 did not support file directories. Also, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
