Determining existence of stream?
Blitz3D Forums/Blitz3D Programming/Determining existence of stream?
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| Is there a command to determine if a variable is a valid stream (tcp in my case)? At some point in my program, my stream becomes not-a-stream, and when I go to end the app I get a mem access violation while trying to close connections. I tried to use "If Eof(stream) <> -1 Then" but it then errored on Eof saying stream was not a stream. Obviously it knows somehow, how can I access that info? I'm not seeing anything relevant in the command reference. |
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| Did the handle variable become zero? Best is, when freeing/closing something to reset the handle to zero. Ie:
file = readfile("test.txt")
closefile file: file = 0
After this, you could determine if the filestream is still valid by checking if (file<>0). |
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| Apparently it's being closed because I am calling closetcpserver right before in the list of things to do before ending the app. I thought that once the connection was handed off with accepttcpstream, they were independent. Good to know. Still, I'd like to know if there's a way to check validity of a stream. |
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| I've posted a complete example in the code-archives of a server-client system, which includes the determination if a stream has been closed or not (client disconnected for example): http://blitzbasic.com/codearcs/codearcs.php?code=2653 From the docs: Eof returns 1 if eof has been reached or, in the case of a TCP stream, the stream has been 'nicely' closed. |
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| Nice example, but I'm already checking for Eof and handling those appropriately. Eof itself errored out saying 'invalid stream'. I figured from the docs that Eof returns -1 if something has gone wrong during stream processing. would cover the variable being an invalid stream, but it does not. |
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| I haven't checked to make sure but doesn't the variable used to hold the stream reference become a positive integer if the stream is open and 0 if it's closed? If so then:
If (myStreamVariable) Then
;do stuff here
Else
;do error message
End If
Should provide the error trapping you need. |
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