Redirecting Windows command ouput to vDosXy [LONG!]

[Carl Distefano cld@xxxxxxxx]

Preamble: To skip over the technical detail and just see what I've been
up to, click on the video link at the bottom of this post.

As you may know from my recent posts and videos about running XyWrite in
various virtual machines, my ongoing quest has been to integrate
XyWrite, particularly XyWrite 4, as closely as possible with the host
64-bit Windows operating system. I've demo'd a way (which I've yet to
document, but will) -- using a folder shared by the host OS and the VM
-- to launch and switch to Windows programs and to issue DOS commands to
the host OS. I've also developed (but not yet shown) a way to redirect
command or program output back to XyWrite. ("Output", of course, means
plain-text output.) This method, which I've dubbed "Xyagra", depends on
having a BATch file running continuously (and harmlessly) on the host
Windows system. Xyagra works well for XyWrite 4 in Oracle VirtualBox
(running either 32-bit Win 7 or W2K), and I've recently shown to my own
satisfaction (but not shared here) that it also works in vDosXy.

That said, I've also documented on the list that vDosXy has internal
hooks that allow Windows commands and programs to be launched directly
from the XyWrite command line:

http://www.freelists.org/post/xywrite/vDosXy-on-second-display,2

So it seemed to me that vDosXy, sans Xyagra, should be potent enough on
its own to redirect 64-bit command and program output -- including Long
Filename output, such as DIR listings -- back to XyWrite. I've been
experimenting with various possibilities -- and experiencing a lot of
frustration along the way. The penny finally dropped, but the solution
was not exactly obvious. Here's a (much-compressed) summary of my trial-
and-error journey to the desired result:

1. DOS

At the vDos command prompt I tried various comands with varying results,
including:

Command : DIR C:\ > C:\DIR.OUT
Result : 8.3 DIR listing in C:\DIR.OUT

Command : CMD.EXE /C DIR C:\ > C:\DIR.OUT
Result : Empty C:\DIR.OUT

Command : CMD.EXE /C "DIR C:\ > C:\DIR.OUT"
Result : Long DIR listing C:\DIR.OUT

The last result was encouraging. Naively, I expected that if I issued
the same command from the XyWrite CMline, LFN output should be directed
to DIR.OUT and it should be possible to get that output into XyWrite by
CAlling DIR.OUT. So...

2. XyWrite 4

In Xy4 I tried many commands similar to the above, often with surprising
-- and disappointing -- results, including the following:

Command : DOS/NV/Z /C DIR C:\ > C:\DIR.OUT
Result : 8.3 DIR listing in C:\DIR.OUT with Ascii-10 newlines(??)

Command : DOS/NV/Z /C CMD.EXE /C DIR C:\ > C:\DIR.OUT
Result : Empty C:\DIR.OUT

And this -- which worked in DOS:
Command : DOS/NV/Z /C "DIR C:\ > C:\DIR.OUT"
Result : 8.3 DIR listing in C:\DIR.OUT with Ascii-10 newlines

Also this:
Command1: DOS/NV/Z /C CMD.EXE /C START DIR C:\ > C:\DIR.OUT
Command2: DOS/NV/Z /C CMD.EXE /C START "DIR C:\ > C:\DIR.OUT"
Result : Empty C:\DIR.OUT (DIR listing scrolls in external window)

In short, no dice. The command that directed the LFN dir listing to a
file at the DOS prompt produced only an 8.3 DIR listing or an empty file
when launched from XyWrite.

Then a light bulb went on, and I tried burying the command in a BATch
file:

Command : DOS/NV/Z /C CMD.EXE /C CDIR.BAT, where CDIR.BAT contains:
     rem start
     @echo off
     cmd.exe /c "DIR C:\ > C:\DIR.OUT"
     exit
     rem end
Result : Long DIR listing in C:\DIR.OUT, editable in XyWrite

At last, success! It's not clear to me why the BATch file works where
the bare command doesn't, but there you have it.

Generalizing from the last example:

Command : DOS/NV/Z /C CMD.EXE /C MYCMD.BAT [Win_command] [args]
     where MYCMD.BAT contains:
     rem start
     @echo off
     cmd.exe /c "%1 %2 %3 %4 %5 %6 %7 %8 %9 > C:\OUTPUT.TXT"
     exit
     rem end
Result : Output of [command] [args] in C:\OUTPUT.TXT

Example A:
DOS/NV/Z /C CMD.EXE /C MYCMD.BAT dir/s f:\*.txt
Output in C:\OUTPUT.TXT:
DIR listing of all .TXT files on drive F:

Example B:
DOS/NV/Z /C CMD.EXE /C MYCMD.BAT tasklist.exe /?
Output in C:\OUTPUT.TXT:
Help screen for Windows tasklist.exe command

Example C (note use of carats to "escape" double-quotes in command):
DOS/NV/Z /C CMD /C MYCMD.BAT tasklist /FI ^"sessionname eq console^"
Output in C:\OUTPUT.TXT:
List of "Console" processes running in the host Windows system.

The technique works not only with CMD.EXE commands, but also with
Windows program output (though it's often necessary to insert a START
command before the program name within the BATch file):

Example D:
DOS/NV/Z /C CMD /C MYCMD.BAT C:\Locate32\locate.exe -lf -R -t jpg
Output in C:\OUTPUT.TXT:
List of all .JPG files on the hard drive

The implications of this technique are ... interesting. For one thing,
it means that you can issue commands to the 64-bit Windows host system
-- using native drive and path names and LFNs, irrespective of whether
those drives and directories are shared with vDos -- and view the
results in XyWrite, without ever leaving XyWrite. (The BATch file and
output file must be on a shared drive, however.)

For another, it means that you can CAll, edit, and SAve files in
XyWrite, again using native Windows paths and long filenames.

I've been working on a suite of U2 routines for Xy4 that proves the
concept and, in my testing so far, works well in practice. Here's a
short video, which I hope you'll enjoy:

http://youtu.be/oG39SdAMHRA

--
Carl Distefano
cld@xxxxxxxx