Question

Write short notes on file control block in operating system

Answer 1

File Control Block (FCB) is a file system structure in which the state of an open file is maintained. A FCB is managed by the operating system, but it resides in the memory of the program that uses the file, not in operating system memory. This allows a process to have as many files open at one time as it wants to, provided it can spare enough memory for an FCB per file.

The FCB originates from CP/M and is also present in most variants of DOS, thatthough only as a backwards compatibility measure in MS-DOS versions 2.0 and later. A full FCB is 36 bytes long; in early versions of CP/M, it was 33 bytes. This fixed size, which could not be increased without breaking application compatibility, lead to the FCB's eventual demise as the standard method of accessing files.

The meanings of several of the fields in the FCB differ between CP/M and DOS, and also depending on what operation is being performed.

The 20-byte-long field starting at offset 0x0C contained fields which (among others) provided further information about the file.

Answer 2

Below is the feature of File control block in operating system

Explanation:

• File Control Block (FCB) is a structure of file system that preserves the state of an open file.  

• The OS(operating system) checks an FCB, but it in the program's memory which uses the file, not the operating system memory.  

• Allows process to have multiple files open at once.

• It can save the memory.

• FCB (File Control Block) is an internal file system framework that is used in the DOS to access disk files.  

• The FCB block includes information about the name of the drive, the filename, the type of file and other information provided by the device when accessing or creating a file.

Learn More:

brainly.in/question/13251628