Unlink (Unix)
In Unix-like operating systems, unlink is a system call and a command line utility to delete files. The program directly interfaces the system call, which removes the file name and (but not on GNU systems) directories like rm and rmdir. If the file name was the last hard link to the file, the file itself is deleted as soon as no program has it open. Unlike the rm utility, the unlink utility only accepts one argument, which can be desirable to guard against accidental multi-deletions. It also appears in the PHP, Node.js, R, Perl and Python standard libraries in the form of the ''unlink()'' built-in function. Like the Unix utility, it is also used to delete files. Examples To delete a file named ''foo'', one could type: % unlink foo In PHP, one could use the following function to do the same: unlink("foo"); The Perl syntax is identical to the PHP syntax, save for the parentheses: unlink "foo"; In Node.js it is almost the same as the others: fs.unlink("foo", callb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
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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] [Amazon] |
Node
In general, a node is a localized swelling (a "knot") or a point of intersection (a vertex). Node may refer to: In mathematics * Vertex (graph theory), a vertex in a mathematical graph *Vertex (geometry), a point where two or more curves, lines, or edges meet. * Node (autonomous system), behaviour for an ordinary differential equation near a critical point * Singular point of an algebraic variety, a type of singular point of a curve In science and engineering Spherical geometry * node, the points where a great circle crosses a plane of reference, or the equator of a sphere Astronomy * Orbital node, the points where an orbit crosses a plane of reference ** Lunar node, where the orbits of the Sun and Moon intersect ** Longitude of the ascending node, how orbital nodes are parameterized Biology * Lymph node, an immune system organ used to store white blood cells * Node of Ranvier, periodic gaps in the insulating myelin sheaths of myelinated axons *Sinoatrial node and atrioven ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
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Ln (Unix)
is a shell command for creating a link file to an existing file or directory. By default, the command creates a hard link, but with the command line option, it creates a symbolic link. Most systems disallow a hard link to a directory since such links could disrupt the structure of a file system and interfere with the operation of other utilities. The command can create a symbolic link to non-existent file. The command appeared in Issue 2 of the X/Open Portability Guidelines. The version in GNU Core Utilities was written by Mike Parker and David MacKenzie. The command is available in Windows via UnxUtils and has been ported to IBM i. Links A link allows more than one path to refer to the same file. A hard link is a directory entry that refers to a file's inode (an internal reference). A file can have multiple hard links each referring to the same inode. Creating a hard link does not copy the contents of the file; but merely causes another name to be associated with the sam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
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Link (Unix)
The link utility is a Unix command line program that creates a hard link from an existing directory entry to a new directory entry. It does no more than call the ''link()'' system function. It does not perform error checking before attempting to create the link. It returns an exit status that indicates whether the link was created (0 if successful, -1 if an error occurred). Creating a link to a directory entry that is itself a directory requires elevated privileges. The '' ln'' command is more commonly used as it provides more features: it can create both hard links and symbolic links, and has error checking. Synopsis link (-s) source target ;source: The pathname of an existing folder or file. ;target: The name of the link to be created. Note that source must specify an existing folder or file, and target must specify a non-existent entry in an existing directory. Standards The link command is part of the Single UNIX Specification (SUS), specified in the ''Shell and Utili ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
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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] [Amazon] |