DEQ DEVTYPE POINT POST WAIT CMS supports the following disk formats for the os and OS/VS sequential and partitioned access methods: Split cylinders User labels Track overflow Alternate tracks
As in OS, the CMS support of the BSP macro produces a return code of
4 when attempting to backspace over a tape mark or when a beginning of
an extent is found on an as data set or a DOS file. If the data set or
file contains split cylinders, an attempt to backspace within an extent,
resulting in a cylinder switch, also produces a return code of 4. Before CMS can read an as data set or DOS file that resides on a disk, you must issue the CMS ACCESS command to make the disk on which it
resides available to CMS. The format of the ACCESS command .L;::). ACCESS cuu moder/ext] You must not specify options or file identification when accessing an OS or DOS disk,. You then issue the FILEDEF command to assign a CMS file identification
to the OS data set or DOS file so that CMS can read it. The format of
the FILEDEF command used for this purpose is: r r "
Flledef rd;:me} IDISK fn ft Ifmll IDSN ? I I IA111 IDSN q1 [q2 ••• ]1 L L .J.J L .J r r
" DISK Ifn ft Ifmll IAll1 L L .J.J DUMMY r , QE!!2ll: iMEMBER membernamel ICONCAT I L .J
Part 3. Conversational Monitor System (eMS) 281
If you are issuing a FILEDEF for a DOS file, note that the OS prograa that will use the DOS file must have a DCB for it. For "ddna.e" in the
FILEDEF command line, use the ddname in that DCB. With the DSJ operand,
enter the file-id of the DOS file. Sometimes, CMS issues the FILEDEF command for you. Although the ces MOVEFILE command, the supported CMS program product interfaces, and the CMS OPEN routine each a default FILEDEF, you should issue the
FILEDEF command yourself to ensure the appropriate file is defined.
After you have issued the ACCESS and FILEDEF commands for an CS sequential or partitioned data set or DOS sequential file, CBS coa.ands (such as ASSEMBLE and STATE) can refer to the OS data set or DOS file
just as if it were a CMS file. Several other CMS commands can be used with OS data sets and Des
files that do not reside on CMS disks. See the Rgfgrgngg for a complete description of the CMS ACCESS, FILEDE', LISTDS, MOVEFILE, QUERY, RELEASE, and STATE commands.
For restrictions on reading OS data sets and tos files under CBS. see
the Ela1!ni1!g ang 2:ystg! Gu.!Qg. The CMS FILEDEF command allows you to specify the I/O device and the
file characteristics to be used by a prograa at execution ti.e. In
conjunction with the OS simulation scheme, FILEDEF siaulates the
functions of the data definition JCL statement.
FILEDEF may be used only with programs using OS macros and functions.
For example:
filedef file1 disk proga data a1
After issuing this command, your program referring to FILE1 would access PROGA DATA on your A-disk.
If you wished to supply data from your terminal for FILE1, you could
issue the command:
filedef file1 terminal
and enter the data for your program without recoapiling.
fi tapein tap2 (recfm fb lrecl 50 block 100 9track den 800) After issuing this command, programs referring to TAPEIN will access a
tape at virtual address 182. (Each tape unit in the eMS environaent bas
a symbolic name associated with it.) The tape must have been previously attached to the virtual machine by the VM/370 operator.
The AUXPROC option can only be used by a program call to FILEDEF and not
from the terminal. The CMS language interface prograas use this feature
for special I/O handling of certain (utility) data sets.
282 IBM VM/370 System Programmer's Guide
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