In COBOL, input and output are record-oriented. Thus the READ, WRITE, DELETE and REWRITE statements process records. The COBOL user is therefore only concerned with the processing of individual records. The following operations are performed automatically:
moving data into input/output areas (buffers) and/or internal storage
validity checking
correcting errors (where feasible)
blocking/unblocking
switching volumes (only for sequential file organization).
Note
The description of input/output statements for sequentially organized files uses the expressions "volume" and "reel". Volume may be used for all input/output devices; reel is applicable to magnetic tape devices only. The handling of disk storage files with sequential access is logically equivalent to the handling of magnetic tape files.
Overview
Statement | Function |
CLOSE | Terminates processing of a file |
DELETE | Deletes a record |
OPEN | Opens a file for processing |
READ | Reads a record |
REWRITE | Replaces a record |
START | Positions within a file |
USE | In addition to input/output statements, USE statements may be supplied to specify error handling procedures (see section "DECLARATIVES") |
WRITE | Writes a record |
DELETE and START are only applicable to relative and indexed file organization.