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Hi PIEBALD,
I typically use two extra (background) threads to read the output and the error streams; it works fine for me on all NT-like versions (there always were problems on Win98/Me). The alternative would be to use the OutputDataReceived and ErrorDataReceived events (available since .NET 2.0), which get handled on a ThreadPool thread.
FWIW: one should not abort a thread; it is troublesome as the outcome is unpredictable.
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Luc Pattyn wrote: one should not abort a thread
Which is part of why I don't want to use one for this; I don't expect any data coming from the error stream anyway.
Personally I have nothing against aborting a thread in such a case.
Luc Pattyn wrote: OutputDataReceived and ErrorDataReceived
But "the ErrorDataReceived event signals each time the process writes a line to the redirected StandardError stream" and I don't want to wait for complete lines, there may not be any newlines in the output -- I want non-blocking IO; if there's no data, just tell me there's no data!
And I expect it's executing on a thread which would have to be aborted in the background, so nothing is gained.
But the real mystery is why the two streams appear to behave differently.
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If you don't like the way the events operate, you'll have to use your own threads and perform some kind of Read() calls. As I said, that is what I do.
BTW: I'm not sure I believe the documentation when it says the events fire on every output/error line, there probably is some buffering going on in the child process, hiding the individual WriteLine operations. I guess it only shows if sufficient data is available (some threshold exceeded) or maybe some data + some timeout.
PIEBALDconsult wrote: But the real mystery is why the two streams appear to behave differently.
I don't remember that. Do they do that consistently? which app(s)?
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Luc Pattyn wrote: Do they do that consistently?
They seem to. Output will return 0 when there's no data, but error will block indefinitely. It could, of course, be due to output having data some times and error never does. I'd have to write a little utility that will write to error to test that out.
Luc Pattyn wrote: which app(s)?
So far, I've been testing with a utility of mine, I'll try it with FTP or something.
WTF!  FTP and telnet don't seem to be prompting when run in a Process!
NSLOOKUP prompts, but I still hang when trying to read the error stream.
modified on Tuesday, March 30, 2010 7:37 PM
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I wrote a little console app that writes its output to error rather than output and it worked fine.
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I just experimented a bit with process stream redirections and created this article[^]. It all works as I expected.
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But what if the slave uses Write rather than WriteLine?
I suppose I could download your code and try that myself...
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the way standard output & error work in .NET is optimized for line-oriented processing; I am guessing the slave process emits output/error data through some buffers, these get transferred occasionally (independent of newlines), the master gets hold of those buffers and searches for line terminators; for each one found it triggers a DataReceived event. AFAIK the underlying i.e. Win32 mechanism is not line-oriented. You not using NewLine means DataReceived events are useless for you, so you need either threads or async operations and collect and parse incoming data yourself.
the one point I have been making is output and error are handled basically the same (although I have a suspicion there may be more buffering at the sender side for stdout than there is for stderr).
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Luc Pattyn wrote: DataReceived events are useless for you
Right. I just tested it and saw what I expected.
Luc Pattyn wrote: underlying i.e. Win32 mechanism is not line-oriented
Right, and using the .BaseStream almost works -- e.g. it works for Output, but not for Error. I wonder whether or not I can get lower...
The only thing I can think of that would cause the difference in behaviour is different backing stores, but why would the two streams have different backing stores? 
P.S. I added commands:
"o" -- Out.Write
"e" -- Error.Write
"a" -- I made autowait an int; "a" decrements it, "A" increments it
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I was just poking around in the non-public fields...
Out is a System.IO.__ConsoleStream
Error is a System.IO.NullStream 
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What is the difference between "Excel 2007 Add-in" project and "Excel 2007 Workbook" project ?
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The Add-in allows you to write a plugin for Excel, and it will be loaded when Excel starts. The first is an application-level addin, the second a document-level addin.
Start here[^] 
I are Troll 
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Hi,
I have a database (access) that contains a table GALLERY.
Now i need while uploading a file to insert the path in this way to the db
"~/photo/XXX.JPG"
What i get right now is only the file's name.
This is what i used for saving the path
FileUpload1.SaveAs(Server.MapPath("~/photo/" + FileUpload1.FileName));
I've tried it with and without the Server.MapPath.
The resault without the server.mappath was "The SaveAs method is configured to require a rooted path..bla bla bla"
With the Server.MapPath it works but not the way i need it. as i said it inserts only the file's name to the DB.
Can anyone please help me with that.
Thank you,
Basil.
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Do not post to multiple forum 
I know the language. I've read a book. - _Madmatt
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What database are you using. If your database generate the problem on saving the file path. You can Encrypt the path and Then save to it.
If you can think then I Can.
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im using an ACCESS DB, what do you mean by encrypting the path
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If you are using Access DB then replace the \ to \\ and save it.
the second method is to save in database is encrypt the path.
If you can think then I Can.
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thanks for your answer, please tell me what do you mean by encrypting the path, you mean to encrypt the path string before inserting to the DB, how would i do that ?
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If your Path Name have a Special Character that database is not support. Then you can use to convert this path to a another string by using diffrent encryption method.
If you can think then I Can.
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i need you to tell me HOW to encrypt it
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My c++ dll takes as input char*.
.
bool testdata(char* data, int dataLen)
From Vb I am doing the following
Declare Function testdata Lib "\abcDLL.dll" (ByRef data As Byte(), ByVal dataLen As Integer) As Boolean
Structure Test
Public header As UInt32
Public lst As UInt32
End Structure
'
Private Function StructToByte(ByVal Struct As Object) As Byte()
Dim iStructSize As Integer = Marshal.SizeOf(Struct)
'Dim iStructSize As Integer = Len(Struct)
Dim buffer As IntPtr = Marshal.AllocHGlobal(iStructSize)
Marshal.StructureToPtr(Struct, buffer, False)
Dim btData(iStructSize - 1) As Byte
Marshal.Copy(buffer, btData, 0, iStructSize)
Marshal.FreeHGlobal(buffer)
Return btData
End Function
While calling the above function
Dim tFrom As Test
tFrom.header = 200
tFrom.lst = 200
Dim ByteArray2() As Byte
ByteArray2 = StructToByte(tFrom)
testdata (ByteArray2, 8)
PROBLEM:
The problem is that when in the dll I type cast the ata into a struc containing only 2 integer, I get incorrect values.
I am strugglign with this for the last 2 days, can anyone plese help me out
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This may be unsafe, but you can directly pass a VB String to C++ dll that take const char * & or something like that depending on whether you pass by value or reference. For that matter you can pass VARIANT or _variant_t's as well using COM.
When you want to modify the string from VBA, then you need to use a bytearray. Otherwise, it is unnecessary.
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