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Pexec
pexec is a command-line utility for Linux and other Unix-like operating systems which allows the user to execute shell commands in parallel. The specified code can be executed either locally or on remote hosts, in which case ssh is used to build a secure tunnel between them. Similar to shell loops, a variable is changed as the loop starting the tasks iterates, so that many values can get passed to the specified command or script. pexec is a free software utility, and part of the GNU Project. It is available under the terms of GPLv3, and is part of the current Debian stable release. Usage The most common usage is to replace the shell loop, for example: for x in alpha bravo charlie delta ; do do_something $x done to the form of: pexec -r alpha bravo charlie delta -e x -o - -c \ 'do_something $x' where the set with the 4 elements of "alpha" "bravo" "charlie" and "delta" define the possible values for the (environmental) variable $x. The program pexec features al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GNU Parallel
GNU parallel is a command-line utility for Linux and other Unix-like operating systems which allows the user to execute shell scripts or commands in parallel. GNU parallel is free software, written by Ole Tange in Perl. It is available under the terms of GPLv3. Usage The most common usage is to replace the shell loop, for example while read x; do do_something "$x" done < list to the form of list contains arguments for do_something and where process_output may be empty.
Scripts using parallel are often easier to read than scripts using pexec.
The program parallel features also
* grouping of and < ...
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Command-line Utility
A console application or command-line program is a computer program (applications or utilities) designed to be used via a text-only user interface. A console application can be used with a computer terminal, a system console, or a terminal emulator included with a graphical user interface (GUI) operating system, such as the Windows Console in Microsoft Windows, the Terminal in macOS, and xterm in the X Window System on Unix-like systems. Console applications can be run from a command-line shell. Overview A user typically interacts with a console application using only a keyboard and display screen, as opposed to GUI applications, which normally require the use of a mouse or other pointing device. Many console applications such as command line interpreters are command line tools, but numerous text-based user interface (TUI) programs also exist. As the speed and ease-of-use of GUIs applications have improved over time, the use of console applications has greatly dimini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Standard Input
In computer programming, standard streams are preconnected 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. When a program is run as a daemon, its standard ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xargs
xargs (short for "extended arguments") is a command on Unix and most Unix-like operating systems used to build and execute commands from standard input. It converts input from standard input into arguments to a command. Some commands such as grep and awk can take input either as command-line arguments or from the standard input. However, others such as cp and echo can only take input as arguments, which is why xargs is necessary. A port of an older version of GNU is available for Microsoft Windows as part of the UnxUtils collection of native Win32 ports of common GNU Unix-like utilities. A ground-up rewrite named is part of the open-source TextTools project. The command has also been ported to the IBM i operating system. Examples One use case of the xargs command is to remove a list of files using the rm command. POSIX systems have an for the maximum total length of the command line, so the command may fail with an error message of "Argument list too long" (meaning that t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Command-line Argument
A command-line interface (CLI) is a means of interacting with software via command (computing), commands each formatted as a line of text. Command-line interfaces emerged in the mid-1960s, on computer terminals, as an interactive and more user-friendly alternative to the non-interactive mode available with punched cards. For a long time, a CLI was the most common interface for software, but today a graphical user interface (GUI) is more common. Nonetheless, many programs such as operating system and software development utility software, utilities still provide CLI. A CLI enables automation, automating computer program, programs since commands can be stored in a scripting language, script computer file, file that can be used repeatedly. A script allows its contained commands to be executed as group; as a program; as a command. A CLI is made possible by command-line interpreters or command-line processors, which are programs that execute input commands. Alternatives to a CLI ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Remote Shell
The remote shell (rsh) is a command-line computer program that can execute shell commands as another user, and on another computer across a computer network. The remote system to which ''rsh'' connects runs the ''rsh'' daemon (rshd). The daemon typically uses the well-known Transmission Control Protocol (TCP) port number 513. History ''Rsh'' originated as part of the BSD Unix operating system, along with rcp, as part of the rlogin package on 4.2BSD in 1983. rsh has since been ported to other operating systems. The rsh command has the same name as another common UNIX utility, the restricted shell, which first appeared in PWB/UNIX; in System V Release 4, the restricted shell is often located at /usr/bin/rsh. As other Berkeley r-commands which involve user authentication, the rsh protocol is not secure for network use, because it sends unencrypted information over the network, among other reasons. Some implementations also authenticate by sending unencrypted pass ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Load (computing)
In UNIX computing, the system load is a measure of the amount of computational work that a computer system performs. The load average represents the average system load over a period of time. It conventionally appears in the form of three numbers which represent the system load during the last one-, five-, and fifteen-minute periods. Unix-style load calculation All Unix and Unix-like systems generate a dimensionless Software metric, metric of three "load average" numbers in the kernel (operating system), kernel. Users can easily query the current result from a Unix shell by running the uptime command: $ uptime 14:34:03 up 10:43, 4 users, load average: 0.06, 0.11, 0.09 The W (Unix), w and top (software), top commands show the same three load average numbers, as do a range of graphical user interface utilities. In operating systems based on the Linux kernel, this information can be easily accessed by reading the procfs, /proc/loadavg file. To explore this kind of infor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mutex
In computer science, a lock or mutex (from mutual exclusion) is a synchronization primitive that prevents state from being modified or accessed by multiple threads of execution at once. Locks enforce mutual exclusion concurrency control policies, and with a variety of possible methods there exist multiple unique implementations for different applications. Types Generally, locks are ''advisory locks'', where each thread cooperates by acquiring the lock before accessing the corresponding data. Some systems also implement ''mandatory locks'', where attempting unauthorized access to a locked resource will force an exception in the entity attempting to make the access. The simplest type of lock is a binary semaphore. It provides exclusive access to the locked data. Other schemes also provide shared access for reading data. Other widely implemented access modes are exclusive, intend-to-exclude and intend-to-upgrade. Another way to classify locks is by what happens when the lock stra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Standard Error Stream
In computer programming, standard streams are preconnected 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. When a program is run as a daemon, its standard ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Standard Output
Standard may refer to: Symbols * Colours, standards and guidons, kinds of military signs * Standard (emblem), a type of a large symbol or emblem used for identification Norms, conventions or requirements * Standard (metrology), an object that bears a defined relationship to a unit of measure used for calibration of measuring devices * Standard (timber unit), an obsolete measure of timber used in trade * Breed standard (also called bench standard), in animal fancy and animal husbandry * BioCompute Standard, a standard for next generation sequencing * ''De facto'' standard, product or system with market dominance * Gold standard, a monetary system based on gold; also used metaphorically for the best of several options, against which the others are measured * Internet Standard, a specification ratified as an open standard by the Internet Engineering Task Force * Learning standards, standards applied to education content * Standard displacement, a naval term describing th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Debian
Debian () is a free and open-source software, free and open source Linux distribution, developed by the Debian Project, which was established by Ian Murdock in August 1993. Debian is one of the oldest operating systems based on the Linux kernel, and is the basis of List of Linux distributions#Debian-based, many other Linux distributions. As of September 2023, Debian is the second-oldest Linux distribution still in active development: only Slackware is older. The project is coordinated over the Internet by a team of volunteers guided by the List of Debian project leaders, Debian Project Leader and three foundational documents: the Debian Social Contract, the Debian Constitution, and the Debian Free Software Guidelines. In general, Debian has been developed openly and distributed freely according to some of the principles of the GNU Project and Free Software. Because of this, the Free Software Foundation sponsored the project from November 1994 to November 1995. However, Debian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linux
Linux ( ) is a family of open source Unix-like operating systems based on the Linux kernel, an kernel (operating system), operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically package manager, packaged as a Linux distribution (distro), which includes the kernel and supporting system software and library (computing), libraries—most of which are provided by third parties—to create a complete operating system, designed as a clone of Unix and released under the copyleft GPL license. List of Linux distributions, Thousands of Linux distributions exist, many based directly or indirectly on other distributions; popular Linux distributions include Debian, Fedora Linux, Linux Mint, Arch Linux, and Ubuntu, while commercial distributions include Red Hat Enterprise Linux, SUSE Linux Enterprise, and ChromeOS. Linux distributions are frequently used in server platforms. Many Linux distributions use the word "Linux" in their name, but the Free ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
