CAll "CBL_OPEN_FILE"
USING FILENAME, ACCESS-MODE, DENY-MODE, DEVICE, HANDLE
RETURNING STATUS-CODE
| FILENAME (PIC X(n)) | This is the name of a file to open. If this file does not exist, the open fails and sets return-code to "1". The filename parameter can be blank-terminated or terminated with low-values. |
| ACCESS-MODE (pic x comp-x) | This is the mode in which to open the file: 1 for Input, 2 for Output, 3 for IO. Any other value will result in the open failing, with a return-code of 1. |
| DENY-MODE (pic x comp-x) | Determines how other users can access the file: 0 to deny read and write access by other users, 1 to deny write access, 2 to deny read access, and 3 to allow all other users. This flag has an effect only on Windows systems. |
| DEVICE (pic x comp-x) | This is not used and must be 0. |
| HANDLE (pic x(4) comp-x) | This is set to the handle of the file opened. Use this handle in the other functions. |
This routine is used for opening files for reading and/or writing and returns 0 on success and non-zero if an error occurred. The error is a special encoding of the digit 9 with the ANSI-74 error code, or the runtime system error number if no ANSI-74 error code pertains to the error. If RETURN-CODE is non-zero after calling this routine, you must process it as a file status, for example:
01 file-status-group.
03 file-status pic xx comp-x.
03 redefines file-status.
05 fs-byte-1 pic x.
05 fs-byte-2 pic x comp-x.
. . .
call "CBL_xxx_FILE" using parameters
if return-code not = 0
move return-code to file-status
. . .
At this point fs-byte-1 contains 9 and fs-byte-2 contains the ANSI-74 error code, or a runtime system error number.
This routine is written in C and is called via the direct method, so it is not possible for the runtime to validate parameters for accuracy. Passing unexpected parameters will result in undefined behavior and possibly even a MAV.