Re: QSH using QTEMP

[fbocch2595@xxxxxxx]

As always, thanks for the explanation.  
 
I've corrected the error and am able to display to qtemp. 
 
Frank  
 
 
-----Original Message-----
From: midrange-l@xxxxxxxxxxxxxxxx
To: midrange-l@xxxxxxxxxxxx
Sent: Wed, 18 Oct 2006 6:09 PM
Subject: Re: QSH using QTEMP



fbocch2595,

(I wish I knew what to you call you, instead of fbocch2595. Do you have a 
name?)

You see, QShell splits it's operation between two jobs.  The interactive 
job that you run the command from becomes a "terminal".  Unix programs 
(like those in QShell) interact with a terminal using 3 different data 
streams.  One for input, called STDIN, one for output called STDOUT, and a 
third one for error messages called STDERR.  When you run a QShell 
utility, your current interactive job becomes a terminal. That terminal 
takes whatever you type and sends it to the STDIN of this other, 
background, job.   Anything that background job writes out to STDOUT or 
STDERR is copied to the screen in your interactive "terminal" job.  That's 
the way QShell works.

The redirection operators change all that.  When you use "ls" by itself, 
it prints the directory list on the screen, but when you do
  "ls > /somewhere/somefile"  the LS command no longer outputs to the 
screen. Instead, it's output has been redirected to a file.  It's never 
sent to the terminal job.

When you try to redirect to QShell, as in your example

ls -c /ProgrammingArchive > /qsys.lib/qtemp.lib/myfile.file/myfile.mbr

Now you have a problem.  The background job has a DIFFERENT QTEMP than 
your foreground job, so this can't possibly work. The MYFILE file is in 
your interactive job's QTEMP, not the background job's QTEMP.  Even if you 
could find a way to make it create the file in the background job's QTEMP, 
it wouldn't do you any good because you'd have no way to retrieve the 
data from it.

So, instead of having the background job redirect it's output to QTEMP, 
you have to do it differently.  In the interactive job, you say "anything 
written to my STDOUT screen, put it in QTEMP".  In that scenario, the 
background job still thinks it's writing to the terminal, so it still 
forwards it to the interactive job.  In the interactive job, you have to 
use OVRDBF to redirect the output.

In other words, this WON'T WORK:

QSH CMD('ls -C /programmingArchive > 
/qsys.lib/qtemp.lib/test.file/test.mbr')

However, THIS WILL:

OVRDBF FILE(STDOUT) TOFILE(QTEMP/TEST)
QSH CMD('ls -C /programmingArchive')
DLTOVR FILE(STDOUT)

If you continue to use the > charcter to do the redirection, the data is 
never sent to the terminal job, so there's no way it'll ever work.

I hope that makes more sense.  I don't know how to explain it better. 
But, rest assured, it DOES work, I use it every day.