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File (command)
file is a shell command for reporting the type of data contained in a file. It is commonly supported in Unix and Unix-like operating systems. As the command uses relatively quick-running heuristics to determine file type, it can report misleading information. The command can be fooled, for example, by including a magic number in the content even if the rest of the content does not match what the magic number indicates. The command report cannot be taken as completely trustworthy. The Single UNIX Specification (SUS) requires the command to exhibit the following behavior with respect to the file specified via the command-line: # If the file cannot be read, or its Unix file type is undetermined, the command will report that the file was processed but its type was undetermined # The command must be able to determine the types directory, FIFO, socket, block special file, and character special file # A zero-length file is reported as such # An initial part of file is considere ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IOS 11
iOS 11 is the iOS version history, eleventh major release of the iOS mobile operating system developed by Apple Inc., Apple, being the successor to iOS 10. It was announced at the company's Worldwide Developers Conference on June 5, 2017, and was released on September 19, 2017. It was succeeded by iOS 12 on September 17, 2018. Overview iOS 11 was introduced at the Apple Worldwide Developers Conference keynote address on June 5, 2017. The first developer beta version was released after the keynote presentation, with the first public beta released on June 26, 2017. iOS 11 was officially released by Apple on September 19, 2017. It brought many changes to iOS. Some major highlights were: * The lock screen and Notification Center were combined, allowing all notifications to be displayed directly on the lock screen. * The control center was completely redesigned, combining all pages into a single unified page. It also brought the ability to rearrange the position of the controls, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heuristic
A heuristic or heuristic technique (''problem solving'', '' mental shortcut'', ''rule of thumb'') is any approach to problem solving that employs a pragmatic method that is not fully optimized, perfected, or rationalized, but is nevertheless "good enough" as an approximation or attribute substitution. Where finding an optimal solution is impossible or impractical, heuristic methods can be used to speed up the process of finding a satisfactory solution. Heuristics can be mental shortcuts that ease the cognitive load of making a decision. Context Gigerenzer & Gaissmaier (2011) state that sub-sets of ''strategy'' include heuristics, regression analysis, and Bayesian inference. Heuristics are strategies based on rules to generate optimal decisions, like the anchoring effect and utility maximization problem. These strategies depend on using readily accessible, though loosely applicable, information to control problem solving in human beings, machines and abstract i ... [...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] |
System V
Unix System V (pronounced: "System Five") is one of the first commercial versions of the Unix operating system. It was originally developed by AT&T and first released in 1983. Four major versions of System V were released, numbered 1, 2, 3, and 4. System V Release 4 (SVR4) was commercially the most successful version, being the result of an effort, marketed as ''Unix System Unification'', which solicited the collaboration of the major Unix vendors. It was the source of several common commercial Unix features. System V is sometimes abbreviated to SysV. , the AT&T-derived Unix market is divided between four System V variants: IBM's AIX, Hewlett Packard Enterprise's HP-UX and Oracle's Solaris, plus the free-software illumos forked from OpenSolaris. Overview Introduction System V was the successor to 1982's UNIX System III. While AT&T developed and sold hardware that ran System V, most customers ran a version from a reseller, based on AT&T's reference implementation. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MIME
A mime artist, or simply mime (from Greek language, Greek , , "imitator, actor"), is a person who uses ''mime'' (also called ''pantomime'' outside of Britain), the acting out of a story through body motions without the use of speech, as a theatrical medium or as a performance art. In earlier times, in English, such a performer would typically be referred to as a mummer. Miming is distinguished from silent comedy, in which the artist is a character in a film or skit without sound. Jacques Copeau, strongly influenced by Commedia dell'arte and Japanese Noh theatre, used masks in the training of his actors. His pupil Étienne Decroux was highly influenced by this, started exploring and developing the possibilities of mime, and developed corporeal mime into a highly sculptural form, taking it outside the realms of naturalism. Jacques Lecoq contributed significantly to the development of mime and physical theatre with his training methods. As a result of this, the practice of mime h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
File Extension
File or filing may refer to: Mechanical tools and processes * File (tool), a tool used to remove fine amounts of material from a workpiece. ** Filing (metalworking), a material removal process in manufacturing ** Nail file, a tool used to gently abrade away and shape the edges of fingernails and toenails Documents * An arranged collection of document A document is a writing, written, drawing, drawn, presented, or memorialized representation of thought, often the manifestation of nonfiction, non-fictional, as well as fictional, content. The word originates from the Latin ', which denotes ...s * Filing (legal), submitting a document to the clerk of a court Computing * Computer file, a resource for storing information ** file URI scheme ** (command), a Unix program for determining the type of data contained in a computer file * File system, a method of storing and organizing computer files and their data * Files by Google, an Android app * Files (Apple), an Apple ap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magic Number (programming)
In computer programming, a magic number is any of the following: * A unique value with unexplained meaning or multiple occurrences which could (preferably) be replaced with a named constant * A constant numerical or text value used to identify a file format or protocol ) * A distinctive unique value that is unlikely to be mistaken for other meanings (e.g., Universally Unique Identifiers) Unnamed numerical constants The term ''magic number'' or ''magic constant'' refers to the anti-pattern of using numbers directly in source code. This breaks one of the oldest rules of programming, dating back to the COBOL, FORTRAN and PL/1 manuals of the 1960s. In the following example that computes the price after tax, 1.05 is considered a magic number: price_tax = 1.05 * price The use of unnamed magic numbers in code obscures the developers' intent in choosing that number, increases opportunities for subtle errors, and makes it more difficult for the program to be adapted and extended ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Device File
In Unix-like operating systems, a device file, device node, or special file is an interface to a device driver that appears in a file system as if it were an ordinary file. There are also special files in DOS, OS/2, and Windows. These special files allow an application program to interact with a device by using its device driver via standard input/output system calls. Using standard system calls simplifies many programming tasks, and leads to consistent user-space I/O mechanisms regardless of device features and functions. Overview Device files usually provide simple interfaces to standard devices (such as printers and serial ports), but can also be used to access specific unique resources on those devices, such as disk partitions. Additionally, device files are useful for accessing system resources that have no connection with any actual device, such as data sinks and random number generators. There are two general kinds of device files in Unix-like operating syst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unix Domain Socket
A Unix domain socket (UDS), a.k.a. local socket, a.k.a. inter-process communication (IPC) socket, is a communication endpoint for exchanging data between processes executing in the same Unix or Unix-like operating system. The name, ''Unix domain socket'', refers to the domain argument value AF_UNIX that is passed to the function that creates a socket system resource. The same communication domain is also selected by AF_LOCAL. Valid type argument values for a UDS are: * SOCK_STREAM (compare to TCP) – for a stream-oriented socket * SOCK_DGRAM (compare to UDP) – for a datagram-oriented socket that preserves message boundaries (as on most UNIX implementations, UNIX domain datagram sockets are always reliable and don't reorder datagrams) * SOCK_SEQPACKET (compare to SCTP) – for a sequenced-packet socket that is connection-oriented, preserves message boundaries, and delivers messages in the order that they were sent The UDS facility is a standard component of a POSIX operatin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Folder (computing)
In computing, a directory is a file system cataloging structure that contains references to other computer files, and possibly other directories. On many computers, directories are known as folders or drawers, analogous to a workbench or the traditional office filing cabinet. The name derives from books like a telephone directory that lists the phone numbers of all the people living in a certain area. Files are organized by storing related files in the same directory. In a hierarchical file system (that is, one in which files and directories are organized in a manner that resembles a tree), a directory contained inside another directory is called a subdirectory. The terms parent and child are often used to describe the relationship between a subdirectory and the directory in which it is cataloged, the latter being the parent. The top-most directory in such a filesystem, which does not have a parent of its own, is called the root directory. The freedesktop.org media type f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unix File Type
The Unix file types are the categories of file formats that a Unix-based system uses to provide context-sensitive behavior of file system items all of which called ''files'' in Unix-based systems. POSIX defines categories: regular, directory, symbolic link, FIFO special, block special, character special, and socket. An operating system may define additional categories (e.g. Solaris doors). A regular file is any file format that the file system does not know and relies on applications to manipulate. The other categories are for file formats that the file system inherently knows and can manipulate. The ls -l command reports a file's category via the character before the permissions information. The file command reports file format information; even for regular files. Representations Numeric The type of a file is specified by the file's mode, which consists of the file type and access permissions. The stat() system call returns information about a file in a structure ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
