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File (command)
The file command is a standard program of Unix and Unix-like operating systems for recognizing the type of data contained in a computer file. History The original version of file originated in Unix Research Version 4 in 1973. System V brought a major update with several important changes, most notably moving the file type information into an external text file rather than compiling it into the binary itself. Most major BSD and Linux distributions use a free, open-source reimplementation which was written in 1986–87 by Ian Darwin from scratch. It was expanded by Geoff Collyer in 1989 and since then has had input from many others, including Guy Harris, Chris Lowth and Eric Fischer; from late 1993 onward its maintenance has been organized by Christos Zoulas. The OpenBSD system has its own subset implementation written from scratch, but still uses the Darwin/Zoulas collection of magic file formatted information. The command has also been ported to the IBM i operating system. ... [...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., being the successor to iOS 10. It was announced at the company's Apple Worldwide Developers Conference, Worldwide Developers Conference on June 5, 2017, and released on September 19, 2017. It was succeeded by iOS 12 on September 17, 2018. Changes iOS 11 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, some of which could be used with 3D Touch for quick access to additional options. * The App Store (iOS), App Store received its first major design overhaul since iOS 7 to focus on editorial content and daily highlights. * A "Files (Apple), Files" file manager app al ... [...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 s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Device File
In Unix-like operating systems, a device file 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 systems, known as ''characte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unix Domain Socket
A Unix domain socket aka UDS or IPC socket ( inter-process communication socket) is a data communications endpoint for exchanging data between processes executing on the same host operating system. It is also referred to by its address family AF_UNIX. Valid socket types in the UNIX domain 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 Unix domain socket facility is a standard component of POSIX operating systems. The API for Unix domain sockets is similar to that of an Internet socket, but rather than using an underlying network protocol, all communication occurs enti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Named Pipe
In computing, a named pipe (also known as a FIFO for its behavior) is an extension to the traditional pipe concept on Unix and Unix-like systems, and is one of the methods of inter-process communication (IPC). The concept is also found in OS/2 and Microsoft Windows, although the semantics differ substantially. A traditional pipe is " unnamed" and lasts only as long as the process. A named pipe, however, can last as long as the system is up, beyond the life of the process. It can be deleted if no longer used. Usually a named pipe appears as a file, and generally processes attach to it for IPC. In Unix Instead of a conventional, unnamed, shell pipeline, a named pipeline makes use of the filesystem. It is explicitly created using mkfifo() or mknod(), and two separate processes can access the pipe by name — one process can open it as a reader, and the other as a writer. For example, one can create a pipe and set up gzip to compress things piped to it: mkfifo my_pipe gzip -9 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Folder (computing)
In computing, a directory is a file system cataloging structure which 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. Overview Historically, and even on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unix File Type
The seven standard Unix file types are ''regular'', ''directory'', ''symbolic link'', ''FIFO special'', ''block special'', ''character special'', and ''socket'' as defined by POSIX. Different OS-specific implementations allow more types than what POSIX requires (e.g. Solaris doors). A file's type can be identified by the ls -l command, which displays the type in the first character of the file-system permissions field. For regular files, Unix does not impose or provide any internal file structure; therefore, their structure and interpretation is entirely dependent on the software using them. However, the file command can be used to determine what type of data they contain. Representations Numeric In the stat structure, file type and permissions (the mode) are stored together in a bit field, which has a size of at least 12 bits (3 bits to specify the type among the seven possible types of files; 9 bits for permissions). The layout for permissions is defined by POSIX to be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
OpenBSD
OpenBSD is a security-focused, free and open-source, Unix-like operating system based on the Berkeley Software Distribution (BSD). Theo de Raadt created OpenBSD in 1995 by forking NetBSD 1.0. According to the website, the OpenBSD project emphasizes "portability, standardization, correctness, proactive security and integrated cryptography." The OpenBSD project maintains portable versions of many subsystems as packages for other operating systems. Because of the project's preferred BSD license, many components are reused in proprietary and corporate-sponsored software projects. The firewall code in Apple's macOS is based on OpenBSD's PF firewall code, Android's Bionic C standard library is based on OpenBSD code, LLVM uses OpenBSD's regular expression library, and Windows 10 uses OpenSSH (OpenBSD Secure Shell) with LibreSSL. The word "open" in the name OpenBSD refers to the availability of the operating system source code on the Internet, although the word "open" in the nam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Christos Zoulas
Christos may refer to: * Jesus Jesus, likely from he, יֵשׁוּעַ, translit=Yēšūaʿ, label=Hebrew/Aramaic ( AD 30 or 33), also referred to as Jesus Christ or Jesus of Nazareth (among other names and titles), was a first-century Jewish preacher and religious ... of Nazareth * Christ (title), a title for the Jewish Messiah in Christianity * Christos (surname) * Christos (given name) *, a Greek owned, Liberian flagged cargo ship in service 1962-71 See also * Christ (other) * Christo (other) * Christa (other) * Christus (other) {{Disambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geoff Collyer
Geoff Collyer (born 1958) is a Canadians, Canadian computer scientist. He is the senior author of ''C News'', a protocol-neutral news transport, and the designer of NOV (computers), NOV, the News Overview database (article index) used by all modern News client, newsreaders. He contributed the code that allowed to convert the Bourne Shell from using the non-portable sbrk to a portable malloc based implementation.http://schilytools.sourceforge.net/bosh.html Bourne Shell project page In the past he worked as a Unix system programmer, but since 1994 he has been living on Plan 9 from Bell Labs, ''Plan 9'' while working at Bell Laboratories. Honors Asteroid 129101 Geoffcollyer, discovered by astronomers at the Jarnac Observatory in Arizona in 2004, was named in his honor. The official was published by the Minor Planet Center on 9 August 2006 (). References External links Geoff Collyers Homepage with publicationsmodified V7 shell sourcemodified V9 shell sourcerecent Plan 9 kern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ian Darwin
Ian or Iain is a name of Scottish Gaelic origin, derived from the Hebrew given name (Yohanan, ') and corresponding to the English name John. The spelling Ian is an Anglicization of the Scottish Gaelic forename ''Iain''. It is a popular name in Scotland Scotland (, ) is a country that is part of the United Kingdom. Covering the northern third of the island of Great Britain, mainland Scotland has a border with England to the southeast and is otherwise surrounded by the Atlantic Ocean to the ..., where it originated, as well as other English-speaking world, English-speaking countries. The name has fallen out of the top 100 male baby names in the United Kingdom, having peaked in popularity as one of the top 10 names throughout the 1960s. In 1900, Ian was the 180th most popular male baby name in England and Wales. , the name has been in the top 100 in the United States every year since 1982, peaking at 65 in 2003. Other Gaelic forms of "John" include "Seonaidh" ("Johnny" fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
