Vista - Problem with WSH Shell Exec StdOut

I'm trying to Use WSH Shell Exec to run a 'command line' program and catch
its StdOut stream in real time. I'm using Nero's NeroCmd.exe to read,
write, erase, and get info about a CD-RW in drive F:. I'm running WXP Pro
SP2. NeroCmd.exe is a command line utility included with or usable with
most versions of Nero in the past 5 or more years, including the free
versions included with many CD/DVD writers, I think.

If I create and run a .bat file with the following on a single line:
C:\WINDOWS\system32\cmd.exe /c "C:\Program Files\Nero\Nero
7\Core\NeroCmd.exe" --erase -- drivename f

then almost immediately I get a command window displaying the following:
C:\Program Files\Windows Resource Kits\Tools>%comspec% /c "C:\Pr\Nero
7\Core\NeroCmd.exe" --erase --drivename f
Erasing disc. This will take 61 seconds.

and after about a minute an "OK." message appears and the command window
closes.

The batch file runs differently if Shell Exec'ed.
Here is the script I'm currently using:
'-------------
Dim WshShell, oExec, input
Set WshShell = CreateObject("WScript.Shell")
Set oExec = WshShell.Exec("test2b.bat")

Do While True
input = "At End Of Stream!"
Do while Not oExec.StdOut.AtEndOfStream
input = Replace(input, "At End Of Stream!", "")
input = input & oExec.StdOut.Read(1)
'Display each line as it is received.
If InStr(input, vbcrlf) <> 0 Then Exit Do
WScript.Sleep 0
Loop
MsgBox "*" & input & "*"
WScript.Sleep 10
Loop
'-------------

Sorry about the endless loop. You have to abort the script by ending the
wscript.exe in windows task manager.

If I use the VBScript above to use the shell object's exec method to run the
script, and to read and display the exec method's StdOut stream in real
time, I immediately get the following:

1: a message box with two asterisks indicating a vbCrLf was received.

2: a message box containing the command:
*C:\Documents and Settings\Paul\My Documents\vbScript\Nero Command
Line>C:\WINDOWS\system32\cmd.exe /c "C:\Program Files\Nero\Nero
7\Core\NeroCmd.exe" --erase --drivename f *

3. after about a minute, I get two more message boxes:

*Erasing disc. This will take 61 seconds.*

and

*Ok.*

and an infinite number of *At End Of Stream!* messages.

To me, this indicates that I am not getting StdOut in real time; the 'this
will take 61 seconds' should have occurred almost immediately rather than
after the erase process was about done.

Is there some change I can make to the script to get the info in real time,
or is it likely that NeroCmd.exe handles StdOut differently when its batch
file is Shell Exec'ed than when run in a plain command line window, and I
just have to live with it?

Thanks for any help you can give me.

-Paul Randall

"Paul Randall" <paulr90@xxxxxx> wrote in message
news:O9DbWTyeJHA.4180@xxxxxxSince you already have a working single-line batch file, what might be the
purpose of creating a 15-line VB Script file to invoke it? If you must use a
VB Script, wouldn't it be more consistent to invoke NeroCmd.exe from within
the VB Script? It would certainly facilitate installation and maintenance!

"Pegasus (MVP)" <I.can@xxxxxx> wrote in message
news:%230$atZyeJHA.4528@xxxxxxThanks for your response.

My real script does Shell Exec indivual NeroCmds, reads the responses, and
branches accordingly, to create one or more CDs whose source files come from
2 GB flash cards. I wanted to post the simplest example that showed a
significant difference between the real-time StdOut and what appears in a
manually invoked command line box using the identical command. I'm hoping
for help in getting info from StdOut in real time. This would help with
providing progress info to the end user. Right now, they just get a blank
black command line window; I think a 'This will take 61 seconds.' message at
the start of the process would be more helpful, but only NeroCmd can give a
reasonable estimate.

-Paul Randall

On Jan 20, 1:11*pm, "Paul Randall" <paul...@xxxxxx> wrote:Redirect the output into a text file to prove that there is in fact a
CR LF combination after the

Erasing disc. This will take 61 seconds.

line of text. My guess is that its LF CR or something else.

Also, why not change this line ...

Do While True

to

Do While oExec.Status = 0

I'd also consider reading the text into a character variable which is
displayed after each cycle through the inner Do loop, something like
this ...

set oCON = createobject("scripting.filesystemobject").open("con",8)

Do While True
input = "At End Of Stream!"
Do while Not oExec.StdOut.AtEndOfStream
input = Replace(input, "At End Of Stream!", "") ' why not just "" ?
c = oExec.StdOut.Read(1)
oCON.Write c
'input = input & c
'Display each line as it is received.
If ASC(c) = 10 or ASC(c) = 13 Then Exit Do
WScript.Sleep 10 ' was this a typo?
Loop
'MsgBox "*" & input & "*"
WScript.Sleep 10
Loop

Run this from the command prompt with CSCRIPT.exe to test.

Tom Lavedas
***********
http://there.is.no.more/tglbatch/

"Paul Randall" <paulr90@xxxxxx> wrote in message
news:OsENNqyeJHA.4180@xxxxxxAFAIK you can't display real time output using the exec method because your
script will not move beyond the line
Set oExec = WshShell.Exec("test2b.bat")
until test2b.bat has finshed its job. When erasing a CD, this will take some
60 seconds.

"Pegasus (MVP)" <I.can@xxxxxx> wrote in message
news:ek$sphzeJHA.4124@xxxxxxThanks for your response. I appreciate your interest in this.

I think I disproved the theory that 'your script will not move beyond the
line ...', when I stated:The echoing of the batch file's command indicates that the StdOut stream is
making that much immediately available. What I don't understand is why none
of NeroCmd.exe's output to StdOut is available until the process ends, if
the batch file or the complete NeroCmd statement is started through WSH
Shell exec. It is all displayed in real time when the batch file or NeroCmd
statement is started manually.

I wish I knew of a native WXP command line utility example that would take a
significant period over which to execute but which only sends a line of
output occasionally, so we could have a VBScript display each line from
StdOut as it occurs. Perhaps you know of something?

-Paul Randall

"Tom Lavedas" <tglbatch@xxxxxx> wrote in message
news:688e9959-bc5c-4c7d-a0b5-2f76f3b903a6@xxxxxx
On Jan 20, 1:11 pm, "Paul Randall" <paul...@xxxxxx> wrote:Redirect the output into a text file to prove that there is in fact a
CR LF combination after the

Erasing disc. This will take 61 seconds.

line of text. My guess is that its LF CR or something else.

Also, why not change this line ...

Do While True

to

Do While oExec.Status = 0

I'd also consider reading the text into a character variable which is
displayed after each cycle through the inner Do loop, something like
this ...

set oCON = createobject("scripting.filesystemobject").open("con",8)

Do While True
input = "At End Of Stream!"
Do while Not oExec.StdOut.AtEndOfStream
input = Replace(input, "At End Of Stream!", "") ' why not just "" ?
c = oExec.StdOut.Read(1)
oCON.Write c
'input = input & c
'Display each line as it is received.
If ASC(c) = 10 or ASC(c) = 13 Then Exit Do
WScript.Sleep 10 ' was this a typo?
Loop
'MsgBox "*" & input & "*"
WScript.Sleep 10
Loop

Run this from the command prompt with CSCRIPT.exe to test.

Tom Lavedas
***********
http://there.is.no.more/tglbatch/

------------------------------------------------------------
Thanks, Tom
I will try your ideas and get back with my results.
My silly 'Do While True' is just a cut and paste from one of the VBScript
examples in the scripting help file.

-Paul Randall

On Jan 20, 3:30*pm, "Paul Randall" <paul...@xxxxxx> wrote:Pegasus' statement that 'your script will not move beyond the
line ...' is, indeed, incorrect. However, there are many other
processes that will block progress. One of them is a Readline or
ReadAll, which you have avoided. I have encountered many situations
where I just could not get 'real time' data out of the Exec method, no
matter how hard I tried. I usually abandon the project, with the
vague hope of investigating further at a later date (which almost
never comes).

One other possibility is that the application is posting its output,
or some of it, to the StdErr rather to StdOut. But, I don't think
your symptoms suggest that. I don't have Nero on this machine, but do
have it on my machine at home. I'll see if I can get a few minutes
tonight to play with this.

In general, I try to avoid Exec, except when I want to execute
something in the console session running the script. Otherwise, I
generally stick to the Run method.

Tom Lavedas
***********
http://there.is.no.more/tglbatch/

Paul Randall schrieb:
[...][...]
I used:

-- sleeper.vbs
Option Explicit
Dim nCount : nCount = 5
Dim nSleep : nSleep = 500
If 0 < WScript.Arguments.Count Then nCount = CInt( WScript.Arguments( 0 ) )
If 1 < WScript.Arguments.Count Then nSleep = CInt( WScript.Arguments( 1 ) )
Do Until 1 > nCount
WScript.Echo "Sleeper", nCount, Now
nCount = nCount - 1
WScript.Sleep nSleep
Loop

-- sleeper.bat
@cho off
echo sleeper.bat start
cscript sleeper.vbs %1 %2
echo sleeper.bat end

-- testsleeper.vbs
Option Explicit

Const WshRunning = 0
Const WshFinished = 1

Dim oWSH : Set oWSH = CreateObject( "WScript.Shell" )
Dim sCmd : sCmd = "cscript sleeper.vbs"
sCmd = "sleeper.bat 5 1000"
Dim oExec : Set oExec = oWSH.Exec( sCmd )
Do Until oExec.Status = WshFinished
WScript.Echo "testSleeper", Now, oExec.StdOut.ReadLine()
Loop

to get

testSleeper 20.01.2009 22:32:44 Sleeper 5 20.01.2009 22:32:44
testSleeper 20.01.2009 22:32:44 Sleeper 4 20.01.2009 22:32:45
testSleeper 20.01.2009 22:32:45 Sleeper 3 20.01.2009 22:32:45
testSleeper 20.01.2009 22:32:45 Sleeper 2 20.01.2009 22:32:46
testSleeper 20.01.2009 22:32:46 Sleeper 1 20.01.2009 22:32:46
testSleeper 20.01.2009 22:32:46
testSleeper 20.01.2009 22:32:47
testSleeper 20.01.2009 22:32:47

resp.

cscript testsleeper.vbs
testSleeper 20.01.2009 22:30:48
testSleeper 20.01.2009 22:30:48 C:\wis\_vbs\0506\dev\forum
testSleeper 20.01.2009 22:30:48 echo sleeper.bat start
testSleeper 20.01.2009 22:30:48 sleeper.bat start
testSleeper 20.01.2009 22:30:48
testSleeper 20.01.2009 22:30:48 C:\wis\_vbs\0506\dev\forum
testSleeper 20.01.2009 22:30:48 cscript sleeper.vbs 5 1000
testSleeper 20.01.2009 22:30:48 Sleeper 5 20.01.2009 22:30:48
testSleeper 20.01.2009 22:30:48 Sleeper 4 20.01.2009 22:30:49
testSleeper 20.01.2009 22:30:49 Sleeper 3 20.01.2009 22:30:50
testSleeper 20.01.2009 22:30:50 Sleeper 2 20.01.2009 22:30:51
testSleeper 20.01.2009 22:30:51 Sleeper 1 20.01.2009 22:30:52
testSleeper 20.01.2009 22:30:52
testSleeper 20.01.2009 22:30:53 C:\wis\_vbs\0506\dev\forum
testSleeper 20.01.2009 22:30:53 echo sleeper.bat end
testSleeper 20.01.2009 22:30:53 sleeper.bat end
testSleeper 20.01.2009 22:30:53
testSleeper 20.01.2009 22:30:53
testSleeper 20.01.2009 22:30:53

I *think* that shows that Exec.StdOut.Read* gets the data as soon as
possible (even if you use an intermediate .bat file).

"ekkehard.horner" <ekkehard.horner@xxxxxx> wrote in message
news:49764409$0$30239$9b4e6d93@xxxxxx-online.net...Yes, I agree that is what it shows. Which implies that NeroCmd does send
its output to StdOut properly when run manually but has a problem when run
within Shell.Exec.

Thanks you for this suite of scripts that demonstrates how nicely StdOut can
work.

-Paul Randall