Initiates the processing of a file. It also performs checking and writing of labels and other I/O operations.
|00||OPEN INPUT||L S R I|
|01||OPEN OUTPUT||L S R I|
|02||OPEN I-O||L S R I|
|03||OPEN EXTEND||L S R I|
|04||OPEN INPUT WITH NO REWIND||L S|
|05||OPEN OUTPUT WITH NO REWIND||L S|
|08||OPEN INPUT REVERSED||L S|
|Key definition block|
|fcd-name-length||Length of filename|
|fcd-lock-mode||Lock mode flags|
|fcd-max-rec-length||Maximum record length|
|fcd-min-rec-length||Minimum record length|
|fcd-filename-address||Pointer to the filename area|
|fcd-key-def-address||Pointer to the key definition block (I)|
|fcd-locktypes||Type of file locks|
|fcd-file status||File status|
|fcd-handle||Pointer to the file; use for all subsequent accesses to this file|
You must have set up a key definition block for this file if it is an indexed file.
You can assign several FCDs to the same physical file and have them all open at the same time. The operating system counts it as just one open file. The physical file is not closed until every logical file assigned to it has been closed.