In this paper, we will discuss how to specify a file protection scheme in UNIX. File management is a critical function in any computer system. From file creation to file protection, proper file management can alleviate common issues allowing a smoother user experience. Background UNIX has a very distinct file system. While the file directory system is similar to Windows, the users Graphical Users Interface (GUI) is not.
UNIX utilizes a command line prompt where Windows provides an actual GUI to interact inside the file system. The standard double-click icon will not pertain to this paper. UNIX users are primarily system developers, programmers, and administrators. A common computer user, such as my workplace, primarily executes operations in a Windows based environment. Protection Scheme Traditional In traditional UNIX, “each UNIX user is assigned a unique user identification number (user ID)” (Stallings, 2012) or UID. When a user creates a file, his or her UID is attached to that file and designated as the owner.
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The user is also a member of a primary group as well as other groups. Allowing 4990 users access to this single file would require a users UID to be a member of either the creator’s primary group or in the group of the file’s parent directory with the proper SetGID permission set. In protecting this file, Bishop states “there are twelve permission bits in the protection word of a file; they customarily divided into groups of three (Bishop, 1987). ” The bits represent the encoded permissions for the file’s owner and details how the file protection scheme is set. Modern
More up to date UNIX and UNIX operating systems such as FreeBSD, OpenBSD, Linux, and Solaris use an access control list for permission setting and file protection. Stallings states “the administrator assigns a list of UNIX user IDs and groups to a file by using the setfac1 command. Any number of users and groups can be associated with a file (Stallings, 2012). ” Access rights are assigned to each user or group by the owner or administrator with three protection bits (read, write, execute). This would allow 4990 users of a 5000 user group some type of access to a particular file. Conclusion
In conclusion, this review covered how to specify and create a protection scheme in UNIX. Either via a traditional UNIX means or through a modern traditional means. Protection schemes are very important. One just has to take the time to understand how a file is protected and apply that knowledge to allow only the proper access to a file.