Jump to content

Data Control Block

Edit links
From Wikipedia, the free encyclopedia
This is an old revision of this page, as edited by Apokrif (talk | contribs) at 22:28, 27 November 2007 (Category:Computer file systems). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

In IBM mainframe operating systems, such as OS/360, MVS, z/OS, a Data Control Block (DCB) is a description of a dataset in a program. A DCB is coded in Assembler programs using the DCB macro instruction (which expands in a large number of "define constant" instructions). High level language programmers use library routines containing DCBs.

A DCB is one of the many control blocks used in these operating systems. A control block is basically a data area with a predefined structure, very similar to a C struct, but typically only related to system's functions. A DCB may be compared to a FILE structure in C, but it is much more complex, offering much more options for various access methods.

Retrieved from "https://en.wikipedia.org/w/index.php?title=Data_Control_Block&oldid=174233746"