Path (computing)
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A path is the general form of a file or directory name, giving a file's name and its unique location in a file system. Paths point to their location using a string of characters signifying directories, separated by a delimiting character, most commonly the slash "/" or backslash character "\", though some operating systems may use a different delimiter. Paths are used extensively in computer science to represent the folder/file relationships common in modern operating systems, and are essential in the construction of URLs.
A path can be either absolute or relative. A full path or absolute path is a path that points to the same location on one file system regardless of the working directory or combined paths. It is usually written in reference to a root directory.
A relative path is a path relative to the current working directory, so the full absolute path may not need to be given.
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[edit] Representations of paths by operating system
| Unix-like operating system | DOS and descendant operating systems like OS/2 and Microsoft Windows | Classic Mac OS | AmigaOS | RISC OS | |
|---|---|---|---|---|---|
| Parent-Child Direction | Left-Right | Left-Right | Left-Right | Left-Right | |
| Root Directory | / | <drive letter>:\ | <drive name>: | <drive, volume or assign name>: | <fs type>::<drive name>.$ |
| Directory Separator | / | \ | : | / | . |
On Unix-like operating systems and on DOS and its descendants, PATH is an environment variable listing directories where executables may be found.
[edit] Universal Naming Convention
The Universal Naming Convention specifies a common syntax for accessing network resources, such as shared folders and printers. The syntax for Windows systems is as follows:
\\computername\sharedfolder\resource
Where 'computername' is the hostname, 'sharedfolder' is a shared directory with a name chosen by the host providing the share, and 'resource' is a shared directory, file, or printer. The hostname may also be identified by a fully-qualified domain name or by IP address. The 'sharedfolder' may exist anywhere on the remote host system, and is not restricted to the filesystem root directory. Linux and Unix-like systems occasionally use a similar syntax, with forward slashes ( / ) in place of backslashes ( \ ), but usually write the syntax as computername:/sharedfolder/resource [1] or, like URLs, for example smb://computername/sharedfolder.
[edit] Example
Here is an example with a Unix style file system as it would appear from a terminal or terminal application (command-line window):
Your current working directory (cwd) is:
/users/mark/
You want to change your current working directory to:
/users/mark/bobapples
At that moment, the relative path for the directory you want is:
./bobapples
and the absolute path for the directory you want is
/users/mark/bobapples
Because bobapples is the relative path for the directory you want, you may type the following at the command prompt to change your current working directory to bobapples:
cd bobapples
Two dots ("..") are used for moving up in the hierarchy, to indicate the parent directory; one dot (".") represents the directory itself. Both can be components of a complex relative path (e.g., "../mark/./bobapples"), where "." alone or as the first component of such a relative path represents the working directory. (Using "./foo" to refer to a file "foo" in the current working directory can sometimes be useful to distinguish it from a resource "foo" to be found in a default directory or by other means; for example, to view a specific version of a man page instead of the one installed in the system.)
Windows also uses the path extensively throughout the modern editions of its operating systems and Office applications, which users can customize. By default, in Windows 98 or above, each folder and Windows Explorer window has an address bar by which you can navigate a different path, or view the path of the current working directory.
The "find" and "search" utilities under Windows have always featured the path as a sortable option, though in Windows 95 the column was truncated by default, allowing the user to resize the "path" column manually until the path became sufficiently visible.
In IE 4 with the Windows Desktop Update and Windows 98, (and above), it is part of the metadata displayed in Windows Explorer's HTML-containing window pane above the search results if you are using the Search sidebar--a function that in Windows XP is seamlessly integrated with Explorer and Internet Explorer's Search sidebar.
Here are some examples of MS-DOS/Windows style paths:
A:\Temp\car.jpeg
This pathname points to a file whose name is car.jpeg, which is located in the directory Temp, which in turn is located in the root directory of the drive A:.
C:..\Launch.avi
This pathname refers to a file called Launch.avi located in the parent directory of the current directory on drive C:.
Program Files\Viewer\viewer.exe
This pathname denotes a file called viewer.exe located in Viewer directory which in turn is located in Program Files directory which is located in the current directory of the current drive (since no drive specification is present in this example).
viewer.exe
This rather simple pathname points to a file named viewer.exe located in the current directory (since no directory specification is present) on the current drive (since no drive specification is present).
[edit] See also
See path to reference other homonyms that use this nomenclature.
[edit] References
This article was originally based on material from the Free On-line Dictionary of Computing, which is licensed under the GFDL.
