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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 $x. The program pexec features also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GNU Parallel
GNU parallel is a command-line driven utility for Linux and other Unix-like operating systems which allows the user to execute shell scripts or commands in parallel. GNU parallel is free software, written by Ole Tange in Perl. It is available under the terms of GPLv3. Usage The most common usage is to replace the shell loop, for example while read x; do do_something "$x" done < list , process_output 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 .
The program parallel features also
* grouping of
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Command-line
A command-line interpreter or command-line processor uses a command-line interface (CLI) to receive commands from a user in the form of lines of text. This provides a means of setting parameters for the environment, invoking executables and providing information to them as to what actions they are to perform. In some cases the invocation is conditional based on conditions established by the user or previous executables. 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. Today, many users rely upon graphical user interfaces and menu-driven interactions. However, some programming and maintenance tasks may not have a graphical user interface and use a command line. Alternatives to the command-line interface include text-based user interface menus (for example, IBM AIX SMIT), keyboard shortcuts, and various desktop metaphors centered on the pointer (u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Standard Input
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 st ... [...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 interpreter or command-line processor uses a command-line interface (CLI) to receive commands from a user in the form of lines of text. This provides a means of setting parameters for the environment, invoking executables and providing information to them as to what actions they are to perform. In some cases the invocation is conditional based on conditions established by the user or previous executables. 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. Today, many users rely upon graphical user interfaces and menu-driven interactions. However, some programming and maintenance tasks may not have a graphical user interface and use a command line. Alternatives to the command-line interface include text-based user interface menus (for example, IBM AIX SMIT), keyboard shortcuts, and various desktop metaphors centered on the pointer (usual ... [...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 514. 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. Limitations As described in the rlogin article, 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 passwords over the netwo ... [...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 metric of three "load average" numbers in the 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 and top commands show the same three load average numbers, as do a range of graphical user interface utilities. In Linux, they can also be accessed by reading the /proc/loadavg file. An idle computer has a load number of 0 (the idle process is not counted). Each process using or waiting for CPU (the ''ready queue'' or run queue) incremen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mutex
In computer science, a lock or mutex (from mutual exclusion) is a synchronization primitive: a mechanism that enforces limits on access to a resource when there are many threads of execution. A lock is designed to enforce a mutual exclusion concurrency control policy, and with a variety of possible methods there exists 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 happe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Standard Error Stream
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 s ... [...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 erro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Debian
Debian (), also known as Debian GNU/Linux, is a Linux distribution composed of free and open-source software, developed by the community-supported Debian Project, which was established by Ian Murdock on August 16, 1993. The first version of Debian (0.01) was released on September 15, 1993, and its first stable version (1.1) was released on June 17, 1996. The Debian Stable branch is the most popular edition for personal computers and servers. Debian is also the basis for many other distributions, most notably Ubuntu. Debian is one of the oldest operating systems based on the Linux kernel. The project is coordinated over the Internet by a team of volunteers guided by the Debian Project Leader and three foundational documents: the Debian Social Contract, the Debian Constitution, and the Debian Free Software Guidelines. New distributions are updated continually, and the next candidate is released after a time-based freeze. Since its founding, Debian has been developed openly a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linux
Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, which includes the kernel and supporting system software and libraries, many of which are provided by the GNU Project. Many Linux distributions use the word "Linux" in their name, but the Free Software Foundation uses the name "GNU/Linux" to emphasize the importance of GNU software, causing some controversy. Popular Linux distributions include Debian, Fedora Linux, and Ubuntu, the latter of which itself consists of many different distributions and modifications, including Lubuntu and Xubuntu. Commercial distributions include Red Hat Enterprise Linux and SUSE Linux Enterprise. Desktop Linux distributions include a windowing system such as X11 or Wayland, and a desktop environment such as GNOME or KDE Plasma. Distributions inten ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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