MPE/iX Intrinsics Reference Manual (32650-90905)

230 Chapter6
Command Definitions (FLUSHLOG-GETUSERMODE)
FOPEN
can be specified on files specified with carriage-control either by
embedding the control in the record or by sending the control code directly
through the
controlcode parameter of FWRITE.
Carriage control is supplied only for ASCII files. This option and the
ASCII/binary option (
foption bit (13:1)) are mutually exclusive, and
attempts to open new files with both binary and carriage control directives
result in an access violation.
If a carriage-control character is sent to a file where the control cannot be
executed directly (for example, line-spacing characters sent to a disk or
tape file), the control character is embedded as the first byte of the record.
If a carriage-control character is sent to other types of files, the control is
transmitted to the driver.
Control codes %400 through %403 are remapped to %100 through %103,
so that they fit into one byte and thus can be embedded. Records written to
the line printer with control codes %400 through %403 should contain only
control information. A record written with control codes %400 through
%403 and no data (count=0, or embedded control and count=1) does not
cause physical I/O of any sort.
To compute record size, the file system assumes carriage-control
information to be part of the data record. Therefore, specifying the
carriage-control option adds one byte to the record size when the file is
originally created. For example, a specification of
REC=-132,1,F,ASCII;CCTL results in a
recsize of 133 bytes.
In general, the entire record can be read (the size of which is returned in
itemnum =67 of the FFILEINFO intrinsic). However, on writes to files where
carriage-control characters are specified, the data transferred is limited to
recsize -1 unless a control of 1 is passed, indicating that the data record is
prefixed with embedded carriage-control characters.
6.1 Labeled tape
0 No labeled tapes
1 Labeled tapes
(ASC) Not valid for asynchronous device files, but may be set if file
direction is anticipated.
Default: 0
5.1
Disallow file equation option
Indicates whether or not to allow file equations. A leading * in a formal file
designator can override the setting to disallow FILE. The following bit
settings are valid:
0 Allow FILE equations to override programmatic or
system-defined file specifications.
1 Disallow FILE equations from overriding programmatic or
system-defined file specifications.