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Re: Changing File Size with OPENU? [message #10215 is a reply to message #10203]

Mon, 27 October 1997 00:00

Wayne Landsman
Messages: 117
Registered: January 1997

Senior Member

William Thompson wrote:
>
> Wayne:
>
> I confirm this behaviour in IDL/v4.0.1 on a DEC Alpha workstation running
> OSF/v4, including the difference in behavior when the "print,fstat(lun)" line
> is uncommented. I can't see how a simple print statement to the terminal
> screen could be expected to affect file I/O, so it must be a bug.
>
> Have you tried writing something other than zeroes to the file? Do the bytes
> go where you expected them to, or to some other location. Is the file simply
> padded out with extra unwanted zeroes, with random values, or with data?
>
What appears to be happening is that the WRITEU statement does not
begin writing at the current position in the file, but first skips 8192
bytes. If I was working under VMS, with its complicated file
structure, I would blame this behaviour on some sort of record
boundary. But since it occurs with Unix files, there must be an
internal IDL bug in the way that WRITEU works on files opened with
OPENU.

--Wayne Landsman
landsman@mpb.gsfc.nasa.gov

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[Message index]

		Re: Changing File Size with OPENU? By: Peter Mason on Tue, 28 October 1997 00:00
		Re: Changing File Size with OPENU? By: Jack Saba on Tue, 28 October 1997 00:00
		Re: Changing File Size with OPENU? By: Peter Mason on Tue, 28 October 1997 00:00
		Re: Changing File Size with OPENU? By: Wayne Landsman on Mon, 27 October 1997 00:00
		Re: Changing File Size with OPENU? By: thompson on Mon, 27 October 1997 00:00

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