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Fc (Unix)
is a standard program on Unix and Unix-like operating systems that lists, edits and re-executes commands previously entered to an interactive shell. Its name is an initialism for "fix command". It is particularly helpful for editing complex, multi-line commands. The ''fc'' command is required to be an "intrinsic" utility by POSIX, and as such is implemented as a builtin in the Bash, Zsh, and Almquist shells. Invoked with no options, ''fc'' will open a text editor, allowing the user to modify the last-run command. Upon exiting the editor, the modified command is executed in the current shell. Various other command-line options are supported, allowing quick substitutions, repetition or modification of a specific command from the session history, or a range of commands from the history. Examples When invoked with the -l flag, ''fc'' will list recent lines from the session history (the last 16 lines by default in the Bash shell): $ fc -l 1 pwd 2 whoami 3 ls 4 ls -a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Open-source Software
Open-source software (OSS) is Software, computer software that is released under a Open-source license, license in which the copyright holder grants users the rights to use, study, change, and Software distribution, distribute the software and its source code to anyone and for any purpose. Open-source software may be developed in a collaborative, public manner. Open-source software is a prominent example of open collaboration, meaning any capable user is able to online collaboration, participate online in development, making the number of possible contributors indefinite. The ability to examine the code facilitates public trust in the software. Open-source software development can bring in diverse perspectives beyond those of a single company. A 2024 estimate of the value of open-source software to firms is $8.8 trillion, as firms would need to spend 3.5 times the amount they currently do without the use of open source software. Open-source code can be used for studying and a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bash (Unix Shell)
In computing, Bash (short for "''Bourne Again SHell''") is an interactive command interpreter and command programming language developed for UNIX-like operating systems. Created in 1989 by Brian Fox for the GNU Project, it is supported by the Free Software Foundation and designed as a 100% free alternative for the Bourne shell (sh) and other proprietary Unix shells. Since its inception, Bash has gained widespread adoption and is commonly used as the default login shell for numerous Linux distributions. It holds historical significance as one of the earliest programs ported to Linux by Linus Torvalds, alongside the GNU Compiler ( GCC). It is available on nearly all modern operating systems, making it a versatile tool in various computing environments. As a command-line interface (CLI), Bash operates within a terminal emulator, or text window, where users input commands to execute various tasks. It also supports the execution of commands from files, known as shell scripts, f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Unix Commands
This is a list of the shell commands of the most recent version of the Portable Operating System Interface (POSIX) IEEE Std 1003.1-2024 which is part of the Single UNIX Specification (SUS). These commands are implemented in many shells on modern Unix, Unix-like and other operating systems. This list does not cover commands for all versions of Unix and Unix-like shells nor other versions of POSIX. See also * GNOME Core Applications * GNU Core Utilities * List of GNU packages * List of KDE applications * List of Unix daemons * Unix philosophy The Unix philosophy, originated by Ken Thompson, is a set of cultural norms and philosophical approaches to Minimalism (computing), minimalist, Modularity (programming), modular software development. It is based on the experience of leading devel ... * References External links IEEE Std 1003.1,2004 specificationsIEEE Std 1003.1,2008 specificationsIEEE Std 1003.1,2024 specifications– configurable list of equivalent pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ed (software)
(pronounced as distinct letters, ) is a line editor for Unix and Unix-like operating systems. It was one of the first parts of the Unix operating system that was developed, in August 1969. It remains part of the POSIX and Open Group standards for Unix-based operating systems, alongside the more sophisticated full-screen editor vi. History and influence The ed text editor was one of the first three key elements of the Unix operating system— assembler, editor, and shell—developed by Ken Thompson in August 1969 on a PDP-7 at AT&T Bell Labs. Many features of ed came from the qed text editor developed at Thompson's alma mater University of California, Berkeley. Thompson was very familiar with qed, and had reimplemented it on the CTSS and Multics systems. Thompson's versions of qed were notable as the first to implement regular expressions. Regular expressions are also implemented in ed, though their implementation is considerably less general than that in qed. Dennis M. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vi (text Editor)
vi (pronounced as two letters, ) is a screen-oriented text editor originally created for the Unix operating system. The portable subset of the behavior of vi and programs based on it, and the ex (text editor), ex editor language supported within these programs, is described by (and thus standardized by) the Single Unix Specification and POSIX. The original code for vi was written by Bill Joy in 1976 as the visual mode (user interface), mode for the ex line editor that Joy had written with Chuck Haley. Joy's ex 1.1 was released as part of the first Berkeley Software Distribution (BSD) Unix release in March 1978. It was not until version 2.0 of ex, released as part of Second BSD in May 1979 that the editor was installed under the name "vi" (which took users straight into ex's visual mode), and the name by which it is known today. Some current implementations of vi can trace their source code ancestry to Bill Joy; others are completely new, largely compatible reimplementations. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Environment Variable
An environment variable is a user-definable value that can affect the way running processes will behave on a computer. Environment variables are part of the environment in which a process runs. For example, a running process can query the value of the TEMP environment variable to discover a suitable location to store temporary files, or the HOME or USERPROFILE variable to find the directory structure owned by the user running the process. They were introduced in their modern form in 1979 with Version 7 Unix, so are included in all Unix operating system flavors and variants from that point onward including Linux and macOS. From PC DOS 2.0 in 1982, all succeeding Microsoft operating systems, including Microsoft Windows, and OS/2 also have included them as a feature, although with somewhat different syntax, usage and standard variable names. Design In all Unix and Unix-like systems, as well as on Windows, each process has its own separate set of environment vari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Examples
Example may refer to: * ''exempli gratia'' (e.g.), usually read out in English as "for example" * .example, reserved as a domain name that may not be installed as a top-level domain of the Internet ** example.com, example.net, example.org, and example.edu: second-level domain names reserved for use in documentation as examples * HMS ''Example'' (P165), an Archer-class patrol and training vessel of the Royal Navy Arts * ''The Example'', a 1634 play by James Shirley * ''The Example'' (comics), a 2009 graphic novel by Tom Taylor and Colin Wilson * Example (musician), the British dance musician Elliot John Gleave (born 1982) * ''Example'' (album), a 1995 album by American rock band For Squirrels See also * Exemplar (other), a prototype or model which others can use to understand a topic better * Exemplum An exemplum (Latin for "example", exempla, ''exempli gratia'' = "for example", abbr.: ''e.g.'') is a moral anecdote, brief or extended, real or fictitious, us ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Text Editor
A text editor is a type of computer program that edits plain text. An example of such program is "notepad" software (e.g. Windows Notepad). Text editors are provided with operating systems and software development packages, and can be used to change files such as configuration files, documentation files and programming language source code. Plain text and rich text There are important differences between plain text (created and edited by text editors) and rich text (such as that created by word processors or desktop publishing software). Plain text exclusively consists of character representation. Each character is represented by a fixed-length sequence of one, two, or four bytes, or as a variable-length sequence of one to four bytes, in accordance to specific character encoding conventions, such as ASCII, ISO/IEC 2022, ISO/IEC 2022, Shift JIS, UTF-8, or UTF-16. These conventions define many printable characters, but also whitespace character, non-printing characters th ... [...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, modern 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 derivati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Z Shell
The Z shell (Zsh) is a Unix shell that can be used as an interactive login shell and as a command interpreter for shell scripting. Zsh is an extended Bourne shell with many improvements, including some features of Bash, ksh, and tcsh. Zsh was created by Paul Falstad in 1990 while he was a student at Princeton University. It combines features from both ksh and tcsh, offering functionality such as programmable command-line completion, extended file globbing, improved variable/array handling, and themeable prompts. Zsh is available for Microsoft Windows as part of the UnxUtils collection and has been adopted as the default shell for macOS and Kali Linux. The "Oh My Zsh" user community website provides a platform for third-party plug-ins and themes, featuring a large and active contributor base. History Paul Falstad wrote the first version of Zsh in 1990 while a student at Princeton University. The name ''zsh'' derives from the name of Yale professor Zhong Shao (then a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shell Builtin
In computing, a shell builtin is a Command (computing), command or a Subroutine, function, exposed by a Shell (computing), shell, that is implemented in the shell itself, instead of an external computer program, program which the shell would load and execute. A shell builtin starts faster than an external program because there is no program loading overhead. However, its implementation code is in the shell program, and thus modifying it requires modifying the shell. Therefore, a shell builtin is usually only used for simple, almost trivial, commands, such as text output. Some commands must be implemented as builtins due to the nature of the operating system. Notably, the cd (command), cd command, which changes the working directory of the shell is often a builtin since a program runs in a separate Process (computing), process and working directory is specific to each process. Running cd as an external program would not affect the working directory of the shell that loaded it. See ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Commercial Software
Commercial software, or, seldom, payware, is a computer software that is produced for sale or that serves commercial purposes. Commercial software can be proprietary software or free and open-source software. Background and challenge While software creation by programming is a time and labor-intensive process, comparable to the creation of physical goods, the reproduction, duplication and sharing of software as digital goods is in comparison disproportionately easy. No special machines or expensive additional resources are required, unlike almost all physical goods and products. Once the software is created it can be copied in infinite numbers, for almost zero cost, by anyone. This made commercialization of software for the mass market in the beginning of the computing era impossible. Unlike hardware, it was not seen as trade-able and commercialize-able good. Software was plainly shared for free (hacker culture) or distributed bundled with sold hardware, as part of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
