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Mount (Unix)
In computing, mount is a command in various operating systems. Before a user can access a file on a Unix-like machine, the file system on the device which contains the file needs to be mounted with the mount command. Frequently mount is used for SD card, USB storage, DVD and other removable storage devices. The command is also available in the EFI shell. Overview The mount command instructs the operating system that a file system is ready to use, and associates it with a particular point in the overall file system hierarchy (its ''mount point'') and sets options relating to its access. Mounting makes file systems, files, directories, devices and special files available for use and available to the user. Its counterpart umount instructs the operating system that the file system should be disassociated from its mount point, making it no longer accessible and may be removed from the computer. It is important to umount a device before removing it since changes to files may have only ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ken Thompson
Kenneth Lane Thompson (born February 4, 1943) is an American pioneer of computer science. Thompson worked at Bell Labs for most of his career where he designed and implemented the original Unix operating system. He also invented the B programming language, the direct predecessor to the C programming language, and was one of the creators and early developers of the Plan 9 operating system. Since 2006, Thompson has worked at Google, where he co-developed the Go programming language. Other notable contributions included his work on regular expressions and early computer text editors QED and ed, the definition of the UTF-8 encoding, and his work on computer chess that included the creation of endgame tablebases and the chess machine Belle. He won the Turing Award in 1983 with his long-term colleague Dennis Ritchie. Early life and education Thompson was born in New Orleans, Louisiana. When asked how he learned to program, Thompson stated, "I was always fascinated with logic a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hard Disk Drive
A hard disk drive (HDD), hard disk, hard drive, or fixed disk is an electro-mechanical data storage device that stores and retrieves digital data using magnetic storage with one or more rigid rapidly rotating platters coated with magnetic material. The platters are paired with magnetic heads, usually arranged on a moving actuator arm, which read and write data to the platter surfaces. Data is accessed in a random-access manner, meaning that individual blocks of data can be stored and retrieved in any order. HDDs are a type of non-volatile storage, retaining stored data when powered off. Modern HDDs are typically in the form of a small rectangular box. Introduced by IBM in 1956, HDDs were the dominant secondary storage device for general-purpose computers beginning in the early 1960s. HDDs maintained this position into the modern era of servers and personal computers, though personal computing devices produced in large volume, like cell phones and tablets, rely on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mtab
The mtab (contraction of '' mounted file systems table'') file is a system information file, commonly found on Unix-like systems. Overview This file lists all currently mounted filesystems along with their initialization options. mtab has a lot in common with fstab, the distinction being that the latter is a configuration file listing which available filesystems should be mounted on which mount points at boot time, whereas the former lists currently mounted ones, which can include manually mounted ones not listed in fstab. Therefore, mtab is usually in a format similar to that of fstab. Most of the time it is possible to directly use lines from mtab in fstab. The file commonly resides in /etc/mtab. In some systems it is a symlink to /proc/mounts. Example Sample mtab contents: /dev/sdb1 / ext3 rw,relatime,errors=remount-ro 0 0 proc /proc proc rw,noexec,nosuid,nodev 0 0 /sys /sys sysfs rw,noexec,nosuid,nodev 0 0 varrun /var/run tmpfs rw,noexec,nosuid,nodev,mode=0755 0 0 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Root Directory
In a computer file system, and primarily used in the Unix and Unix-like operating systems, the root directory is the first or top-most directory in a hierarchy. It can be likened to the trunk of a tree, as the starting point where all branches originate from. The root file system is the file system contained on the same disk partition on which the root directory is located; it is the filesystem on top of which all other file systems are mounted as the system boots up. Unix-like systems Unix abstracts the nature of this tree hierarchy entirely and in Unix and Unix-like systems the root directory is denoted by the / (slash) sign. Though the root directory is conventionally referred to as /, the directory entry itself has no name its path is the "empty" part before the initial directory separator character (/). All file system entries, including mounted file systems are "branches" of this root. chroot In UNIX-like operating systems, each process has its own idea of what the root ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Man Page
A man page (short for manual page) is a form of software documentation usually found on a Unix or Unix-like operating system. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts. A user may invoke a man page by issuing the man command. By default, man typically uses a terminal pager program such as more or less to display its output. Man pages are often referred to as an ''on-line'' or ''online'' form of software documentation, * even though the man command does not require internet access, dating back to the times when printed ''out-of-band'' manuals were the norm. History In the first two years of the history of Unix, no documentation existed. The Unix Programmer's Manual' was first published on November 3, 1971. The first actual man pages were written by Dennis Ritchie and Ken Thompson at the insistence of their manager Doug McIlroy in 1971. Aside from the man pages, the ''Programmer' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GConf
GConf was a system used by the GNOME desktop environment for storing configuration settings for the desktop and applications. It is similar to the Windows Registry. It was deprecated as part of the GNOME 3 transition. Migration to its replacement, GSettings and dconf, is ongoing. Changes to this system are controlled by GConfd, a daemon. GConfd watches out for changes to the database, and when they are changed, it applies the new settings to applications using it. This technology is known as "auto-apply", compared to "explicit-apply", which requires users to press an OK or Apply button to make changes come into effect. The term "instant-apply" is sometimes used, compared to plain "apply". The GConf database by default uses a system of directories and XML files, stored in a directory called ~/.gconf. GConf can also use other backends, such as a database server, but XML file storage is the most common configuration. The application gconf-editor is provided to allow users to cha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GNOME-VFS
GnomeVFS (short for GNOME Virtual File System) was an abstraction layer of the GNOME platform for the reading, writing and execution of files. Before GNOME 2.22 GnomeVFS was primarily used by the appropriate versions of Nautilus file manager (renamed to GNOME Files) and other GNOME applications. A cause of confusion is the fact that the file system abstraction used by the Linux kernel is also called the virtual file system (VFS) layer. This is however at a lower level. Due to perceived shortcomings of GnomeVFS a replacement called GVfs was developed. GVfs is based on GIO and allows partitions to be mounted through FUSE. With the release of GNOME 2.22 in April 2008, GnomeVFS was declared deprecated in favor of GVfs GVfs (abbreviation for GNOME virtual file system) is GNOME's userspace virtual filesystem designed to work with the I/O abstraction of GIO, a library available in GLib since version 2.15.1. It installs several modules that are automatically use ... and GIO, requ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HAL (software)
HAL (Hardware Abstraction Layer or rather Hardware Annotation Library) is a software subsystem for UNIX-like operating systems providing hardware abstraction. HAL is now deprecated on most Linux distributions and on FreeBSD. Functionality is being merged into udev on Linux as of 2008–2010 and devd on FreeBSD. Previously, HAL was built on top of udev. Some other OS-es which don't have an alternative like udev or devd still use HAL. The purpose of the hardware abstraction layer was to allow desktop applications to discover and use the hardware of the host system through a simple, portable and abstract API, regardless of the type of the underlying hardware. HAL for Linux OS was originally envisioned by Havoc Pennington. It became a freedesktop.org project, and was a key part of the software stack of the GNOME and KDE desktop environments. It is free software, dual-licensed under both the GNU General Public License and the Academic Free License. HAL is unrelated to the conc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Automounter
An automounter is any program or software facility which automatically mounts filesystems in response to access operations by user programs. An automounter system utility (daemon under Unix), when notified of file and directory access attempts under selectively monitored subdirectory trees, dynamically and transparently makes local or remote devices accessible. The automounter has the purpose of conserving local system resources and of reducing the coupling between systems which share filesystems with a number of servers. For example, a large to mid-sized organization might have hundreds of file servers and thousands of workstations or other nodes accessing files from any number of those servers at any time. Usually, only a relatively small number of remote filesystems (''exports'') will be active on any given node at any given time. Deferring the mounting of such a filesystem until a process actually needs to access it reduces the need to track such mounts, increasing reliabil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wrapper Library
Wrapper libraries (or library wrappers) consist of a thin layer of code (a "shim") which translates a library's existing interface into a compatible interface. This is done for several reasons: * To refine a poorly designed or complicated interface * Allow code to work together which otherwise cannot (e.g. incompatible data formats) * Enable cross language and/or runtime interoperability Wrapper libraries can be implemented using the adapter, façade, and to a lesser extent, proxy design patterns. Structure and implementation The specific way in which a wrapper library is implemented is highly specific to the environment it is being written in and the scenarios which it intends to address. This is especially true in the case when cross language/runtime interoperability is a consideration. Example The following provides a general illustration of a common wrapper library implementation. In this example, a C++ interface acts as a "wrapper" around a C-language interface. C in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virtual Drive
Virtual disk and virtual drive are software components that emulate an actual disk storage device. Virtual disks and virtual drives are common components of virtual machines in hardware virtualization, but they are also widely used for various purposes unrelated to virtualization, such as for the creation of logical disks. Operation A virtual drive is a software component that emulates an actual disk drive, such as an optical disc drive, a floppy disk drive, or a hard disk drive. To other programs, a virtual drive looks and behaves like an actual physical device. A virtual disk may be in any of the following forms: * Disk image, a computer file that contains the exact data structure of an actual storage device * Logical disk (also known as vdisk), an array of two or more actual drives that cooperatively act like a single device * RAM disk, which stores its data in random-access memory (RAM) instead of on a storage device * A mapped network drive that connects to a File Server U ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Disk Image
A disk image, in computing, is a computer file containing the contents and structure of a disk volume or of an entire data storage device, such as a hard disk drive, tape drive, floppy disk, optical disc, or USB flash drive. A disk image is usually made by creating a sector-by-sector copy of the source medium, thereby perfectly replicating the structure and contents of a storage device independent of the file system. Depending on the disk image format, a disk image may span one or more computer files. The file format may be an open standard, such as the ISO image format for optical disc images, or a disk image may be unique to a particular software application. The size of a disk image can be large because it contains the contents of an entire disk. To reduce storage requirements, if an imaging utility is filesystem-aware it can omit copying unused space, and it can compress the used space. History Disk images were originally (in the late 1960s) used for backup and disk clo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
