Topic: file directory

topics > computer science > operating system > Group: file system


alias names
descriptive naming
hierarchical naming
hierarchical structures
hypertext nodes made of names
name server or name directory
symbol table
unique numeric names as surrogates
using icons to represent objects in a user interface


Files are described through a file directory which contains each file's name, location, sizing, record keys, and data description. System utilities are used for displaying the information, deleting and rearranging files, and backing up modifications. File name patterns are useful for maintaining a large number of interrelated files. Increased robustness is provided by duplicated directory information with each file's data, and unique file identifiers with a time and location stamp. A database may include many file directories with file names specifying a particular directory or implying a directory search. A directory search may be user defined, or may scan the current directory, then the system directory, and finally a master directory. (cbb 5/80)
Subtopic: directory as location up

Quote: users overwhelmingly prefer to locate files by location or application rather than by keyword or filename pattern [»barrD7_1995]

Subtopic: namespace up

Quote: a file directory consists of unique, file name entries; root directory at top [»daleRC_1965]
Quote: in V, each object manager implements names for its objects; since name lookup is only one step of an operation; also simpler consistency [»cherDR3_1988]
Quote: every Acme command is interpreted in the directory named by the corresponding window tag [»pikeR1_1994]
Quote: Unix searches for commands in user's directory, /bin directory, and /usr/bin directory [»mashJR_1976]
Quote: Star file drawers correspond to a shared file server with access rights [»smitDC_1982]
Quote: an OS6 file index associates names (e.g., 'LinePrinter' and 'Text') with files; a file has two or more associations [»stoyJE3_1972]

Subtopic: distributed namespace up

Quote: all Vesta repositories share the same namespace; /vesta followed by an Internet domain name [»heydA_2006]
Quote: Vesta subtrees may be replicated; the agreement invariant says that no name is bound to different values in different repositories
Quote: most operations on a Vesta repository affect only one repository; the rest use two repositories; all operations maintain the agreement invariant [»heydA_2006]
Quote: the Vesta repository operations are create, append, replace a master stub, make a ghost, copy between appendable directories, create a non-master stub, and transfer mastership [»heydA_2006]

Subtopic: hierarchy up

Quote: a file system should be hierarchical; for grouping related files; efficient and simple [»ritcDM7_1978b]
Quote: in Inferno and Plan 9, all resources have a hierarchical file name in a forest of file systems and in a private name space [»dorwSM1_1997]
Quote: tree maps show 2-3 thousand hierarchical nodes by encoding information as a rectangle, with a color and sound; e.g., TreeViz for directories [»shneB1_1993]
Quote: Thoth's file system is a tree in which each node is a file [»cherDR2_1979]
Quote: Unix has universal names for the current and parent directories; . and .. [»ritcDM7_1978a]
Quote: early UNIX systems allowed an arbitrary, directed graph of directories; became too chaotic; even now, multiple links cause problems [»thomK7_1978]
Quote: each user has an index accessible from the OS6 system index (e.g., 'JES', 'Index'); may include other indices [»stoyJE3_1972]
Quote: a hierarchical directory structure enables passing a subhierarchy to computations and principals

Subtopic: security up

Quote: each principal has a root directory of retained objects

Subtopic: relative and absolute naming up

Quote: colons separate directory names, * indicates the parent, a leading : indicates a relative path from the working directory [»daleRC_1965]
Quote: every Vesta process has a current or working directory for relative paths, and a root directory for absolute paths; defined when the process is forked [»heydA_2006]

Subtopic: mutable vs. immutable up

Quote: Vesta implements immutable and mutable directories; an immutable directory holds versioned, immutable source files [»heydA_2006]
Quote: a Vesta repository stores every version of every file as immutable sources in a hierarchical name space; the path includes a version name or number

Subtopic: capabilities vs. link/mount up

Quote: unique, system-wide names by capabilities better than symbolic links and remote mounting
Quote: CapaFS uses capability file names for ubiquitous access and delegation; separates user identification from authorization [»regaJT8_2001]
Quote: a CapaFS file name consists of the server in plain text and encrypted path name, access rights, and timeout; use secure channel and capability revocation [»regaJT8_2001]
Quote: refer to objects via the index of a capability pointing to a directory [»dennJB3_1966]

Subtopic: link files up

Quote: an OS6 index may include links to other index entries [»stoyJE3_1972]
Quote: entries in a file directory point to files, other directories, or other entries (links) [»daleRC_1965]

Subtopic: mounting a directory or volume up

Quote: organize file system into volumes for system administration, e.g., for backup and restore [»satyM1_1992]
Quote: volumes needed for managing large distributed file systems; i.e., part of a single disk partition that is associated with a user [»howaJH2_1988]
Quote: the 'mount' command turns a file into the root directory of a removable volume [»ritcDM7_1978a]
Quote: files on different devices are treated the same, but no inter-device links [»ritcDM7_1978a]
Quote: Unix implements 'mount' by a table of leaf i-nodes to block devices; when path reaches leaf, continues at root of the block device [»thomK7_1978]

Subtopic: in-memory directory up

Quote: Vesta keeps directory structure in memory with files stored as shortids [»heydA_2006]
Quote: Vesta stores directories as a DAG of base pointers plus lists of changes
Quote: a Vesta longid is a 32-byte encoding of a directory path by index number; gives parent directory; never reused

Subtopic: network directory up

Quote: an NFS file handle is a 32-byte reference to a file or directory [»heydA_2006]
Quote: the NFS file handle for Vesta files in volatile directories is a shortid plus fingerprint

Subtopic: bind directories up

Quote: Plan 9 uses the same name for different files/services in different processes; fundamental to system [»pikeR6_2000]
Quote: bind rearranges the name space for a process; e.g., replace PATH by binding directories to /bin; same as mount [»pikeR6_2000]

Subtopic: accurate path name up

Quote: use creator as the accurate path name to a file; avoids problems with mounts and symbolic links [»pikeR6_2000]

Subtopic: directory of strings -> file ID, etc. up

Quote: each file (branch) in a file directory stores its physical address, creation time, modified time, access control, and its current state such as open for reading by N users [»daleRC_1965]
Quote: the full name of a file is file id, version number, page 0; a directory associates strings with full names [»lampBW4_1974]
Quote: Amoeba has separate file and directory servers; one handles storage, the other naming and protection; works well [»taneAS12_1990]
Quote: Amoeba creates a file and its directory entry in separate operations; garbage collects if inaccessible (may be impractical for a huge system)
Quote: Oberon file directory by a B-tree
Quote: an index defines the internal name for objects in a backing store server; objects exist as long as a name exists [»birrAD9_1980]

Subtopic: self-descriptive files up

Quote: for Alto and Pilot, a file's leader page defined the file's directory and string name; the actual directory entry was just a hint [»lampBW10_1983]
Quote: disk file headers allow directories to be recreated [»freeP_1976]

Subtopic: file management by date up

Quote: directory and software management by running commands according to file dates; e.g., print all files changed since last listing [»feldSI4_1979]

Subtopic: deleted and reserved files up

Quote: can delete a file's body, both header and body, and/or its index entry; garbage-collection removes unusable items [»stoyJE3_1972]
Quote: a Vesta ghost is a deleted file; a stub is a placeholder or reserved name; builds do not use ghosts or stubs [»heydA_2006]

Subtopic: directory editor up

Quote: edited a directory directly, e.g., delete a line of text or rename a file [»frasCW3_1980]

Related Topics up

Group: database   (27 topics, 665 quotes)
Group: naming   (32 topics, 789 quotes)

Topic: alias names (39 items)
Topic: descriptive naming (29 items)
Topic: file (22 items)
Topic: hierarchical naming (28 items)
Topic: hierarchical structures (46 items)
Topic: hypertext nodes made of names (13 items)
Topic: name server or name directory (40 items)
Topic: namespace (19 items)
Topic: symbol table (4 items)
Topic: unique numeric names as surrogates (67 items)
Topic: using icons to represent objects in a user interface
(10 items)

Updated barberCB 4/05
Copyright © 2002-2008 by C. Bradford Barber. All rights reserved.
Thesa is a trademark of C. Bradford Barber.