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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] |
Shell (computing)
An operating system shell is a computer program that provides relatively broad and direct access to the system on which it runs. The term ''shell'' refers to how it is a relatively thin Abstraction layer, layer around an operating system. A shell is generally a command-line interface (CLI) program although some graphical user interface (GUI) programs are arguably classified as shells too. Overview Operating systems provide various services to their users, including File manager, file management, Process (computing), process management (running and terminating Application program, applications), batch processing, and operating system monitoring and configuration. Most operating system shells are not ''direct'' interfaces to the underlying Kernel (operating system), kernel, even if a shell communicates with the user via peripheral devices attached to the computer directly. Shells are actually special applications that use the kernel API in just the same way as it is used by ot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arbitrary-precision Arithmetic
In computer science, arbitrary-precision arithmetic, also called bignum arithmetic, multiple-precision arithmetic, or sometimes infinite-precision arithmetic, indicates that calculations are performed on numbers whose digits of precision are potentially limited only by the available memory of the host system. This contrasts with the faster fixed-precision arithmetic found in most arithmetic logic unit (ALU) hardware, which typically offers between 8 and 64 bits of precision. Several modern programming languages have built-in support for bignums, and others have libraries available for arbitrary-precision integer and floating-point math. Rather than storing values as a fixed number of bits related to the size of the processor register, these implementations typically use variable-length arrays of digits. Arbitrary precision is used in applications where the speed of arithmetic is not a limiting factor, or where precise results with very large numbers are required. It should ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chown
, short for change owner, is a shell command for changing the owning user of Unix-based file system files including special files such as directories. The ownership of a file may only be altered by a super-user (such as via sudo). A regular user cannot ''give away'' their ownership of a file. The version of chown bundled in GNU coreutils was written by David MacKenzie and Jim Meyering. The command is available for Windows Windows is a Product lining, product line of Proprietary software, proprietary graphical user interface, graphical operating systems developed and marketed by Microsoft. It is grouped into families and subfamilies that cater to particular sec ... via UnxUtils. The command was ported to IBM i. See also * * * * References https://en.m.wikipedia.org/wiki/Chown# External links * chown manual pageby The Linux Information Project (LINFO) {{Core Utilities commands Operating system security Standard Unix programs Unix SUS2008 utilit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chmod
is a shell command for changing access permissions and special mode flags of files (including special files such as directories). The name is short for ''change mode'' where ''mode'' refers to the permissions and flags collectively. The command originated in AT&T Unix version 1 and was exclusive to Unix and Unix-like operating systems until it was ported to other operating systems such as Windows (in UnxUtils) and IBM i. In Unix and Unix-like operating systems, a system call with the same name as the command, , provides access to the underlying access control data. The command exposes the capabilities of the system call to a shell user. As the need for enhanced file-system permissions grew, access-control lists were added to many file systems to augment the modes controlled via . The implementation of bundled in GNU coreutils was written by David MacKenzie and Jim Meyering. Use Although the syntax of the command varies somewhat by implementation, it generally acc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chgrp
, short for change group, is a shell command for changing the group associated with a Unix-based file system file including special files such as directories. Changing the group of a file is restricted to a super-user (such as via ) or to the file's owning user if the user is in the specified group. A file has access permissions for the owning user, a group and for others. Changing the group for a file changes access to it based on users' group memberships. History The command was originally developed as part of the Unix operating system by AT&T Bell Laboratories. It is available in most Unix-like systems, Plan 9, Inferno and IBM i. The version of chgrp bundled in GNU coreutils was written by David MacKenzie. Use Generally, the syntax can be described as: chgrp 'options''''group'' ''files'' * ''group'' specifies the group with which the files should be associated; may be either a symbolic name or an identifier An identifier is a name that identifies (that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Call Graph
A call graph (also known as a call multigraph) is a control-flow graph, which represents calling relationships between subroutines in a computer program. Each node represents a procedure and each edge ''(f, g)'' indicates that procedure ''f'' calls procedure ''g''. Thus, a cycle in the graph indicates recursive procedure calls. Basic concepts Call graphs can be dynamic or static. A dynamic call graph is a record of an execution of the program, for example as output by a profiler. Thus, a dynamic call graph can be exact, but only describes one run of the program. A static call graph is a call graph intended to represent every possible run of the program. The exact static call graph is an undecidable problem, so static call graph algorithms are generally overapproximations. That is, every call relationship that occurs is represented in the graph, and possibly also some call relationships that would never occur in actual runs of the program. Call graphs can be defined to repre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cflow
GNU cflow is a flow graph generator that is part of the GNU Project. It reads a collection of C source files and generates a C flow graph of external references. It uses only sources and does not need to run the program. History It was initially an implementation of the UNIX utility cflow. cflow (UNIX utility) cflow is a Unix command generating a C-language flowgraph. Besides GNU, there are other implementations of ''cflow'', like the one for Tru64 Unix Tru64 UNIX is a discontinued 64-bit UNIX operating system for the DEC Alpha, Alpha instruction set architecture (ISA), currently owned by Hewlett-Packard (HP). Previously, Tru64 UNIX was a product of Compaq, and before that, Digital Equipment Corp ....« cflow - Tru64 Unix » ''HP website'', 2011. References< ...
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Cd (command)
is a shell command that changes the working directory. It is available in many shells and other applications that maintain a working directory. In some contexts, the command can perform actions other than change directory. Some environments provide the change directory feature via a different command name such as . Implementations Generally, a computer system that provides access to a hierarchical file system, provides a change directory command to set the working directory. As this applies to most operating system shells, most support a change directory command, including Unix and Unix-like (i.e. Linux) shells, and Microsoft shells including Command Prompt and PowerShell. Other operating systems with shells supporting the command include OS/2, TRIPOS, AmigaOS (where the command is implied for an input path), ReactOS, DOSBox, and UEFI. * On MS-DOS, the command is available in version 2 and later * DR DOS 6.0 includes the command as both and * On HP MPE/iX the c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cat (Unix)
cat is a shell command for writing the content of a file or input stream to standard output. The name is an abbreviation of ''concatenate'' which is from the Latin ''catenare'' meaning "to chain" Originally developed for Unix, it is available on many operating systems and shells today. In addition to combining files, cat is commonly used to copy files and in particular to copy a file to the terminal monitor. Unless re-directed, outputs file content on-screen. History cat was part of the early versions of Unix, e.g., Version 1. It replaced pr, a PDP-7 and Multics command for copying a single file to the screen. It was written by Ken Thompson and Dennis Ritchie. The implementation of cat bundled in GNU coreutils was written by Torbjorn Granlund and Richard Stallman. The ReactOS implementation was written by David Welch, Semyon Novikov, and Hermès Bélusca. Over time, alternative utilities such as tac and bat also became available, bringing different new features. Use ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cal (command)
is a command-line utility on a number of computer operating systems including Unix, Plan 9, Inferno and Unix-like operating systems such as Linux that prints an ASCII calendar of the given month or year. If the user does not specify any command-line options, cal will print a calendar of the current month. The command is a standard program on Unix and specified in the Single UNIX Specification. Implementations The cal command was present in 1st Edition Unix. A cal command is also part of ASCII's ''MSX-DOS2 Tools'' for MSX-DOS version 2. It is also available for FreeDOS. This implementation only supports the Gregorian calendar (New Style) and may be distributed freely, with or without source. The FreeDOS version was developed by Charles Dye. Examples $ cal February 2024 Su Mo Tu We Th Fr Sa 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 $ cal -3 (shows the previous, current and next month) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C (programming Language)
C (''pronounced'' '' – like the letter c'') is a general-purpose programming language. It was created in the 1970s by Dennis Ritchie and remains very widely used and influential. By design, C's features cleanly reflect the capabilities of the targeted Central processing unit, CPUs. It has found lasting use in operating systems code (especially in Kernel (operating system), kernels), device drivers, and protocol stacks, but its use in application software has been decreasing. C is commonly used on computer architectures that range from the largest supercomputers to the smallest microcontrollers and embedded systems. A successor to the programming language B (programming language), B, C was originally developed at Bell Labs by Ritchie between 1972 and 1973 to construct utilities running on Unix. It was applied to re-implementing the kernel of the Unix operating system. During the 1980s, C gradually gained popularity. It has become one of the most widely used programming langu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compiler
In computing, a compiler is a computer program that Translator (computing), translates computer code written in one programming language (the ''source'' language) into another language (the ''target'' language). The name "compiler" is primarily used for programs that translate source code from a high-level programming language to a lower level language, low-level programming language (e.g. assembly language, object code, or machine code) to create an executable program.Compilers: Principles, Techniques, and Tools by Alfred V. Aho, Ravi Sethi, Jeffrey D. Ullman - Second Edition, 2007 There are many different types of compilers which produce output in different useful forms. A ''cross-compiler'' produces code for a different Central processing unit, CPU or operating system than the one on which the cross-compiler itself runs. A ''bootstrap compiler'' is often a temporary compiler, used for compiling a more permanent or better optimised compiler for a language. Related software ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
