File Sharing


Shared Files ( Acyclic Graph Directories )

Q      Explain file sharing ?       ---           3 Marks.

Ans :      When multiple programmers work on a single project, they need to share files. Files associated with a project can be put in one subdirectory and these file can be selectively shared by many users.

                Each user sharing a file will like to have that file in his own directory . A tree structure of directory does not allow sharing of files. The directory must be organized as directed a cyclic graph or AGD, rather than a tree.

                It may be noted that shared file is not the same as two copies of the file with two copies of a file, if one user changes the file, the changes will not be visible in other’s copy. With a shared file, only one copy of the actual file exists. Shared files are implemented in UNIX using a link. A link is effectively a pointer to another file. If a directory entry is marked as link, then the name of the real file is included in the link information.

file sharing

                In UNIX, only the true owner of the file has a pointer to the i- node. Users who not I – node pointers when the owner removes the file, it is destroyed.


  • WikiNote Foundation

Last modified: Friday, 20 September 2019, 3:22 PM