MPE/iX Intrinsics Reference Manual (32650-90875)

Chapter 4 121
Command Definitions (ABORTSESS - FCLOSE)
FCLOSE
•A disposition code of 1 (rewind and unload) implies the close of an entire volume set.
• If unlabeled magnetic tape is closed with a
disposition code of 0, 1, or 4, and the tape
was written to while open, FCLOSE writes three EOFs at the end of the tape before
performing a rewind or rewind/unload. This ensures that all tapes have an acceptable
number of EOF marks at the end. The three EOFs are written only after the last
FCLOSE occurs, before the rewind, and only if the tape was written on.
• For circular files, deletion of disk space beyond the end-of-file is not allowed.
• If the new file status time stamp has changed, FCLOSE updates this time stamp in the
file label on disk.
(ASC) For serial devices:
• If one of the following device settings is altered programmatically, the device returns to
the system default at FCLOSE:
• Disable read timeout (value set by FCONTROL
itemnum =4).
• Disable subsystem break (enabled through FCONTROL
itemnum =17).
• Enable printing a string of three exclamation points (!!!) when a line is deleted
(disabled through FCONTROL
itemnum =35).
• Disable transparent editing (enabled through FCONTROL
itemnum =41).
These are only the control actions taken by the device control software; additional
changes can result from actions taken by other software modules. For example, if your
program disables the system break feature, break is reenabled on FCLOSE by the CI
software.
• For most device settings that can be programmatically altered, ensure that the altered
characteristics are returned to their original settings when the program ends unless the
altered setting define the way the device should act. For example, if the speed setting of
a device is programmatically altered, you should return the terminal to its original
setting unless the new speed setting should remain in effect for other files opened
against the device.
• When all files have been closed on a device and the device is no longer under the control
of a program or session, all device characteristics are returned to those specified by the
device's configuration.
Directories exist only in the permanent file domain. Permanent (001) and no change are
the only values supported for disposition (13:3) bits when filenum references a
directory. Attempts to move a directory from the permanent file domain to either the new
or temporary file domain will fail with a CCL condition code and the directory remains
open. Directories cannot be deleted by FCLOSE. Attempts to release a directory will fail
with a CCL condition and the directory remains open.
Condition Codes
CCE (2) Request granted.
CCG (0) Not returned.
CCL (1) Request denied. The file was not closed; an incorrect
filenum was