> -----Original Message-----
> From: IBM Mainframe Discussion List
> [mailto:IBM-***@BAMA.UA.EDU] On Behalf Of Kirk Wolf
> Sent: Wednesday, November 28, 2007 4:50 PM
> To: IBM-***@BAMA.UA.EDU
> Subject: Why isn't OMVS command integrated with ISPF?
> I normally use an ssh or (non-3270) telent session to get a
> "real" Unix
> shell on z/OS, but sometimes it is necessary or convenient to
> the the TSO
> OMVS command. It has always bothered me as to why this thing
> wasn't an ISPF
> dialog so that you could split the screen, etc. Doesn't this
> bother anyone
> else or am I missing an obvious work-around?
> I thought it might be nice to write an OMVS replacement as an
> ISPF dialog,
> but it is not obvious to me that it is very easy to do...
> What you would like is a multithreaded (multiple TCBs under z/OS) ISPF
> application - one thread handles normal input processing, and
> the other
> updates a temporary scrollable table with the output as it
> arrives. I
> could be wrong, but ISPF seems to be limited to a single thread and to
> "half-duplex" 3270 conversations. I could work around the
> problem, but there doesn't seem to be a way in ISPF to support a
> "full-duplex" 3270 conversations.
> Comments appreciated,
> Kirk Wolf
> Dovetailed Technologies LLC
From what IBM has said, the problem is that the UNIX terminal I/O is
basically asynchronous or maybe it was "full duplex". 3270 in TSO is not
full duplex, by design (or misdesign). ISPF uses the basic TSO
facilities for terminal I/O (TPUT/TGET/TPG?). The OMVS interface, from
what I was told, works by waiting some period of time for output from
the UNIX command. During this time, any output from the UNIX command is
sent to the TSO session and displayed. When the "timer pops", the OMVS
command in TSO "hangs a read" command (TGET?) to the terminal. During
this time, the UNIX command's output cannot be displayed (it is being
buffered). That's why you need to press the PF10 (refresh) key
periodically. This takes the OMVS interface out of "input mode",
displays any queued output, and sets the timer again.
I only use the TSO OMVS interface when I need to do a set of short
I use ISHELL, at times, to run some UNIX commands.
I use OSHELL at other times to run some UNIX commands.
I use option 3.17 (z/OS 1.8) to edit UNIX files.
I use telnet/ssh when I plan to do a lot of UNIX work (Hummingbird
emulator on Windows or the bundled telnet/ssh on my Linux desktop).
In some cases, I use vim on my Linux desktop to edit files on Linux.
This is in a directory on the Linux system which is exported via NFS to
the z/OS sytem (chmod 1777 on Linux). The z/OS NFS client mounts the
directory with XLAT(Y) to do automatic ASCII<->EBCDIC translation. I
then use a z/OS UNIX command such as "OSHELL cp /nfs/mounted/file
/zos/file" to copy the Linux resident file onto a z/OS filesystem.
Unfortunately, NFS is a bit of a CPU hog, so I don't do this often.
In a truly weird scenario. I've been known to copy the file from z/OS to
the Linux desktop (via NFS), vim edit it to do some regular expression
changes, copy the file back from Linux to z/OS (via NFS), then use 3.17
to finish up my editing. I really despise the z/OS UNIX version of "vi".
I also don't much care for the UNIX shell on z/OS compared to bash on
Linux. But that last may just be that I'm not used to it.
Senior Systems Programmer
Keeping the Promise of Affordable Coverage
Administrative Services Group
The information contained in this e-mail message may be privileged
and/or confidential. It is for intended addressee(s) only. If you are
not the intended recipient, you are hereby notified that any disclosure,
reproduction, distribution or other use of this communication is
strictly prohibited and could, in certain circumstances, be a criminal
offense. If you have received this e-mail in error, please notify the
sender by reply and delete this message without copying or disclosing
For IBM-MAIN subscribe / signoff / archive access instructions,
send email to ***@bama.ua.edu with the message: GET IBM-MAIN INFO
Search the archives at http://bama.ua.edu/archives/ibm-main.html