I'm trying to write a simple backup script. I'd like to use wsh.exec
to run the command line Winzip to create a zip file and capture the
StdOut and write it to a log. It works just fine as long as I don't
try and capture the StdOut of the command line Winzip component. In
the script below E: is a local drive containing the folder to be
backed up. The problem is commented in the code.

Set FSO = CreateObject("Scripting.FileSystemObject")
Set Shell = CreateObject("WScript.Shell")

Set TextStream = FSO.CreateTextFile("C:\backup.txt")

TextStream.WriteLine("Backup of hostname at: " & now)
TextStream.WriteBlankLines(2)
TextStream.WriteLine("Zip operation beginning")

Zipfile = datepart("yyyy", today) & datepart("m", today) &
datepart("d", today) & ".zip"
Set Cmd = Shell.Exec("c:\Program Files\Winzip\wzzip.exe -r -p e:\" &
Zipfile & " " & folder)

' if the following line is commented out the script works.
' otherwise it hangs the script and it never completes
result = Cmd.StdOut.ReadAll()
TextStream.WriteLine(result)

set Cmd = nothing
Set Shell = nothing

TextStream.Close
set FSO = Nothing

If I try and capture the StdOut the logfile (backup.txt) is created
and contains about 10 lines of the StdOut of the command. Thinking
it's trying to capture the StdOut before completion of the script and
that's causing it to hang I tried adding a

Do While Cmd.Status = 0
Wsh.Sleep 1000
Loop

before the result = Cmd.StdOut.ReadAll() to have the script wait for
the completion of the command but no luck. The same problem happened.
Any suggestions would be greatly appreciated.

I cannot make that work with Exec. It hangs after ten
files are added to archive and I just can't seem to figure
out why. I do have a workaround using the Run method
instead ...

Set FSO = CreateObject("Scripting.FileSystemObject")
Set Shell = CreateObject("WScript.Shell")

Set TextStream = FSO.CreateTextFile("C:\backup.txt")

TextStream.WriteLine("Backup of hostname at: " & now)
TextStream.WriteBlankLines(2)
TextStream.WriteLine("Zip operation beginning")
TextStream.Close

Zipfile = Year(Now) & Month(Now) & Day(Now) & ".zip"

sCmd = """c:\Program Files\Winzip\wzzip.exe"" -r -p e:\" _
& Zipfile & " " & folder & " >>c:\backup.txt"

nRes = Shell.Run("%comspec% /c " & sCmd)

Set Shell = nothing

TextStream.Close
set FSO = Nothing
wsh.echo "Done"

Tom Lavedas
===========

>-----Original Message-----
>I'm trying to write a simple backup script. I'd like to
use wsh.exec
>to run the command line Winzip to create a zip file and
capture the
>StdOut and write it to a log. It works just fine as long
as I don't
>try and capture the StdOut of the command line Winzip
component. In
>the script below E: is a local drive containing the
folder to be
>backed up. The problem is commented in the code.
>
> Set FSO = CreateObject("Scripting.FileSystemObject")
> Set Shell = CreateObject("WScript.Shell")
>
> Set TextStream = FSO.CreateTextFile("C:\backup.txt")
>
> TextStream.WriteLine("Backup of hostname at: " & now)
> TextStream.WriteBlankLines(2)
> TextStream.WriteLine("Zip operation beginning")
>
> Zipfile = datepart("yyyy", today) & datepart("m",
today) &
>datepart("d", today) & ".zip"
> Set Cmd = Shell.Exec("c:\Program
Files\Winzip\wzzip.exe -r -p e:\" &
>Zipfile & " " & folder)
>
> ' if the following line is commented out the script
works.
> ' otherwise it hangs the script and it never completes
> result = Cmd.StdOut.ReadAll()
> TextStream.WriteLine(result)
>
> set Cmd = nothing
> Set Shell = nothing
>
> TextStream.Close
> set FSO = Nothing
>
>If I try and capture the StdOut the logfile (backup.txt)
is created
>and contains about 10 lines of the StdOut of the command.
Thinking
>it's trying to capture the StdOut before completion of
the script and
>that's causing it to hang I tried adding a
>
> Do While Cmd.Status = 0
> Wsh.Sleep 1000
> Loop
>
>before the result = Cmd.StdOut.ReadAll() to have the
script wait for
>the completion of the command but no luck. The same
problem happened.

FYI,
I've seen some odd character garbage echoed from the Winzip command line
tool when using it through telnet connections with limited telnet clients; I
don't have a good explanation, but I have found that the following seems to
usually work OK - I'm also using the latest version of the commandline
client...

on error resume next
do until exec.StdErr.AtEndofStream and exec.StdOut.AtEndOfStream
wscript.sleep 10
WScript.StdErr.WriteLine exec.StdErr.ReadLine
WScript.StdOut.WriteLine exec.StdOut.ReadLine
loop


Tom Lavedas wrote:
[..]

"Tom Lavedas" <tlavedas> wrote in message news:280a
> I cannot make that work with Exec. It hangs after ten
> files are added to archive and I just can't seem to figure
> out why.

Apparently StdOut has an 8000 byte buffer size limit. In order to get
anything more than that from it you need to pull from it before it
fills up. If the buffer fills up it hangs whatever process is writing
to StdOut. It's detailed in this newsgroup post
http://groups.google.com/groups?hl=e...%40tkmsftngp05
and this msdn article
http://msdn.microsoft.com/library/de...ng11132000.asp
(search for amazing). The workaround is to do what Alex outlined below
which is to constantly read from StdOut until the process is finished.
I haven't gotten it to work yet but if I do I'll post working code.
This is VERY frustrating.

Mark DuPrey

I had been exploring the issue of reading the output
incrementally. The part I missed was that Wzzip.exe spews
unprintable characters to StdErr that need to be processed
to keep that buffer from overflowing as well.

With that bit of knowledge, I've constructed something
that works for me ...

Set FSO = CreateObject("Scripting.FileSystemObject")
Set Shell = CreateObject("WScript.Shell")

Set TextStream = FSO.CreateTextFile("C:\backup.txt")

TextStream.WriteLine("Backup of hostname at: " & now)
TextStream.WriteBlankLines(2)
TextStream.WriteLine("Zip operation beginning")

Zipfile = Year(Now) & Month(Now) & Day(Now) & ".zip"
folder = "."
sCmd = "c:\Program Files\Winzip\wzzip.exe -r -p c:\" _
& Zipfile & " " & folder
set Cmd = Shell.Exec(sCmd)

Do Until Cmd.StdOut.AtEndofStream
result = result & Cmd.StdOut.Read(1)
if Not Cmd.StdErr.AtEndofStream Then _
result = result & Cmd.StdErr.Read(1)
Loop

TextStream.Write result

set Cmd = nothing
Set Shell = nothing

TextStream.Close
set FSO = Nothing

wsh.echo "Done"

I think this could still run into trouble in some instance
because the 'read loop' is NOT fast enough to keep the
buffer empty. That is, some text remained in the StdOut
buffer after the Exec process was ended. The procedure
above reads it all, but quite a few bytes remained in the
buffer after the Wzzip.exe process had ended in my testing
in a folder with 201 short text files.

In addition, the script above puts all of the StdErr text
into the Result stream. Change the .StdErr.Read(1) to a
Skip(1) to see the difference.

Tom Lavedas
===========

>"Tom Lavedas" <tlavedas> wrote in
message news:280a
>> I cannot make that work with Exec. It hangs after ten
>> files are added to archive and I just can't seem to
figure
>> out why.
>
>Apparently StdOut has an 8000 byte buffer size limit. In
order to get
>anything more than that from it you need to pull from it
before it
>fills up. If the buffer fills up it hangs whatever
process is writing
>to StdOut. It's detailed in this newsgroup post
>[..]
8&selm=uVGoh2gRBHA.1904%40tkmsftngp05
>and this msdn article
>[..]
url=/library/en-us/dnclinic/html/scripting11132000.asp
>(search for amazing). The workaround is to do what Alex
outlined below
>which is to constantly read from StdOut until the process
is finished.
>I haven't gotten it to work yet but if I do I'll post
working code.
[..]

am 24.11.2003 17:30 sprach Mark DuPrey dieses:


> I'm trying to write a simple backup script. I'd like to use wsh.exec
> to run the command line Winzip to create a zip file and capture the
> StdOut and write it to a log. It works just fine as long as I don't
> try and capture the StdOut of the command line Winzip component. In
> the script below E: is a local drive containing the folder to be
> backed up. The problem is commented in the code.

On Win98 my scripts used to hang for some Exec.StdOut.ReadAll()-Operations,
mostly those using command.com /c <some_cmdlinetool>.
While others - mostly Win32-CmdLine Exes- like ping.exe - worked well

ReadAll() expects an EndOfStream-Signal otherwise it will eternally
hang, waiting for EOF, even if the WshExec is terminated (status == 1).
To my opion there is a bug in signaling the EndOfStream-Signal
from command.com to the WshExec-TextStream.

If you're running your script on NT or later, of course, this can not be
the reason.

On the other hand "wzzip.exe" seems to use special streams, since you can't
pipe an "Enter" into its StdIn-Stream if you're using the unregistered
version, which displays an "This is shareware, please Register and press any
key"-Screen before starting the zip operation (This results in a hanging
script aswell, because Exec.Stdin.Write <any char> won't work.
wzzip somehow realizes that the key is send programmatically, not manually)
I switched to winrar for unzipping zipped F-Prot signatures, because
rar.exe doesn't display nasty Shareware-Reminders before doing work ;-)

BTW, I just looked at the output to the StdErr from Wzzip.exe. The
utility is sending a 'Searching ..." progress message followed by some
"blinking" periods to the console to denote progress and then erasing
the output using backspaces when it finds what it is searching for.
It makes sense, but was unexpected (by me, at least).

Tom Lavedas
===========

PS. Alex, is this what you were asking about over in .vbscript?

"Tom Lavedas" <tlavedas> wrote in message news:280a
[..]

Yes, this was what I was thinking about when I clicked the wrong thread. :)

I tend to redirect output/error to a single file and then read it back using
the Escape() function when I run into situations like that, just to figure
out what the dickens those characters are. Takes some work until you get a
boilerplate script going with it, but then it's fast.


Tom Lavedas wrote:
[..]