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Expand (Unix)
expand is a program that converts tab characters into groups of space characters, while maintaining correct alignment. It is available in Unix operating systems and many Unix-like operating systems. The command is available as a separate package for Microsoft Windows as part of the UnxUtils collection of native Win32 ports of common GNU Unix-like utilities. Example For example: $ echo -e "foo\tbar" , expand , xxd -g 1 -u 0000000: 66 6F 6F 20 20 20 20 20 62 61 72 0A foo bar. $ echo -e "foo\tbar" , xxd -g 1 -u 0000000: 66 6F 6F 09 62 61 72 0A foo.bar. $ Here the echo command prints a string of text that includes a tab character, then the output is directed into the expand command. The resulting output is then displayed in hexadecimal and as characters by the xxd dump command. At the second prompt, the same echo output is sent directly to the xxd command. As can be seen by comparing the two, the expand program converts the tab (specifi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unix
Unix (, ; trademarked as UNIX) is a family of multitasking, multi-user computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, and others. Initially intended for use inside the Bell System, AT&T licensed Unix to outside parties in the late 1970s, leading to a variety of both academic and commercial Unix variants from vendors including University of California, Berkeley ( BSD), Microsoft (Xenix), Sun Microsystems ( SunOS/ Solaris), HP/ HPE ( HP-UX), and IBM ( AIX). The early versions of Unix—which are retrospectively referred to as " Research Unix"—ran on computers such as the PDP-11 and VAX; Unix was commonly used on minicomputers and mainframes from the 1970s onwards. It distinguished itself from its predecessors as the first portable operating system: almost the entire operating system is written in the C programming language (in 1973), which allows U ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Native (computing)
Native describes a computing system as operating directly with an underlying technology; with no intervening communication or translation layers. Native software Native software is built to be executed directly by processors that implement a compatible instruction set. A program that runs natively on one platform is runnable on another platform via an emulator if an emulator is available and, generally, with significant runtime speed degradation. For example, games for a Game Boy (typically distributed as a cartridge), generally run natively on a Game Boy which is relatively incompatible with other computer platforms. To run such a game on another processor, software that emulates the Game Boy hardware is required. Cross-platform software can run on multiple processors although possibly requiring it to be re-built for different target systems. Native API A native application programming interface (API) provides direct access to an underlying technology. For example, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unexpand
unexpand is a command in Unix and Unix-like operating systems. It is used to convert groups of space characters into tab characters. For example: $ echo " asdf sdf" , unexpand , od -c 0000000 \t \t a s d f s d f \n 0000014 $ echo " asdf sdf" , od -c 0000000 0000020 a s d f s d f \n 0000032 Here the echo command prints a string of text that includes multiple consecutive spaces, then the output is directed into the unexpand command. The resulting output is then displayed by the octal dump command od. At the second prompt, the same echo output is sent directly through the od command. As can be seen by comparing the two, the unexpand program converts sequences of eight spaces into single tabs (printed as '\t'). See also *List of Unix commands * Expand (Unix) References External linksThe program's manpage A man page (short for manual page) is a form of software documentation found on Uni ... [...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] |
Hexadecimal
Hexadecimal (also known as base-16 or simply hex) is a Numeral system#Positional systems in detail, positional numeral system that represents numbers using a radix (base) of sixteen. Unlike the decimal system representing numbers using ten symbols, hexadecimal uses sixteen distinct symbols, most often the symbols "0"–"9" to represent values 0 to 9 and "A"–"F" to represent values from ten to fifteen. Software developers and system designers widely use hexadecimal numbers because they provide a convenient representation of binary code, binary-coded values. Each hexadecimal digit represents four bits (binary digits), also known as a nibble (or nybble). For example, an 8-bit byte is two hexadecimal digits and its value can be written as to in hexadecimal. In mathematics, a subscript is typically used to specify the base. For example, the decimal value would be expressed in hexadecimal as . In programming, several notations denote hexadecimal numbers, usually involving a prefi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Echo (command)
echo is shell command that writes input text to standard output. It is available in many operating system and shells. It is often used in a shell script to log status, provide feedback to the user and for debugging. For an interactive session, output by default displays on the terminal screen, but output can be re-directed to a file or piped to another process. Many shells implement echo as a builtin command rather than an external application as are many other commands. Multiple, incompatible implementations of echo exist in different shells. Some expand escape sequences by default; some do not; some accept options; some do not. The POSIX specification leaves the behavior unspecified if the first argument is -n or any argument contains backslash characters while the Unix specification (XSI option in POSIX) mandates the expansion of some sequences and does not allow any option processing. In practice, many echo implementations are not compliant in the default environm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Porting
In software engineering, porting is the process of adapting software for the purpose of achieving some form of execution in a computing environment that is different from the one that a given program (meant for such execution) was originally designed for (e.g., different CPU, operating system, or third party library). The term is also used when software/hardware is changed to make them usable in different environments. Software is ''portable'' when the cost of porting it to a new platform is significantly less than the cost of writing it from scratch. The lower the cost of porting software relative to its implementation cost, the more portable it is said to be. This is distinct from cross-platform software, which is designed from the ground up without any single " native" platform. Etymology The term "port" is derived from the Latin '' portāre'', meaning "to carry". When code is not compatible with a particular operating system or architecture, the code must be "carried" to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Windows API
The Windows API, informally WinAPI, is the foundational application programming interface (API) that allows a computer program to access the features of the Microsoft Windows operating system in which the program is running. Programs can access API functionality via shared-library technologies or via system-file access. Each major version of the Windows API has a distinct name that identifies a compatibility aspect of that version. For example, Win32 is the major version of Windows API that runs on 32-bit systems. The name, Windows API, collectively refers to all versions of this capability of Windows. Microsoft provides developer support via a software development kit, Microsoft Windows SDK, which includes documentation and tools for building software based on the Windows API. Services This section lists notable services provided by the Windows API. Base Services Base services include features such as the file system, devices, processes, threads, and error handl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UnxUtils
UnxUtils is a collection of utility programs that provide popular Unix-based shell commands ported from GNU implementations as native Windows programs that depend only on Win32 and the Microsoft C- runtime ( msvcrt.dll). The collection was last updated externally on April 15, 2003, by Karl M. Syring. , the most recent release was an open-source project at SourceForge, with the latest binary release in March, 2007 (though the files are dated 2000). The independent distribution included a main zip archive (UnxUtils.zip, 3,365,638 bytes) complemented by more recent updates (UnxUpdates.zip, 878,847 bytes, brought some binaries up to year 2003), but the SourceForge project has no UnxUpdates.zip package. An alternative collection of Unix-based utilities for Windows is GnuWin32. It has later versions of many programs, but requires supporting files (e.g. DLLs). Supported commands include: * agrep *ansi2knr * basename * bc *bison *bunzip2 *bzip2 *bzip2recover * cat *chgrp *chm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unix-like
A Unix-like (sometimes referred to as UN*X, *nix or *NIX) operating system is one that behaves in a manner similar to a Unix system, although not necessarily conforming to or being certified to any version of the Single UNIX Specification. A Unix-like Application software, application is one that behaves like the corresponding List of POSIX commands, Unix command or Unix shell, shell. Although there are general Unix philosophy, philosophies for Unix design, there is no technical standard defining the term, and opinions can differ about the degree to which a particular operating system or application is Unix-like. Some well-known examples of Unix-like operating systems include Linux, FreeBSD and OpenBSD. These systems are often used on servers as well as on personal computers and other devices. Many popular applications, such as the Apache HTTP Server, Apache web server and the Bash (Unix shell), Bash shell, are also designed to be used on Unix-like systems. Definition The Open ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microsoft 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 sectors of the computing industry – Windows (unqualified) for a consumer or corporate workstation, Windows Server for a Server (computing), server and Windows IoT for an embedded system. Windows is sold as either a consumer retail product or licensed to Original equipment manufacturer, third-party hardware manufacturers who sell products Software bundles, bundled with Windows. The first version of Windows, Windows 1.0, was released on November 20, 1985, as a graphical operating system shell for MS-DOS in response to the growing interest in graphical user interfaces (GUIs). The name "Windows" is a reference to the windowing system in GUIs. The 1990 release of Windows 3.0 catapulted its market success and led to various other product families ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operating System
An operating system (OS) is system software that manages computer hardware and software resources, and provides common daemon (computing), services for computer programs. Time-sharing operating systems scheduler (computing), schedule tasks for efficient use of the system and may also include accounting software for cost allocation of Scheduling (computing), processor time, mass storage, peripherals, and other resources. For hardware functions such as input and output and memory allocation, the operating system acts as an intermediary between programs and the computer hardware, although the application code is usually executed directly by the hardware and frequently makes system calls to an OS function or is interrupted by it. Operating systems are found on many devices that contain a computerfrom cellular phones and video game consoles to web servers and supercomputers. , Android (operating system), Android is the most popular operating system with a 46% market share, followed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
