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Re: Reading files with unknown amount of data [message #1466 is a reply to message #1465]

Thu, 30 September 1993 10:47

jim
Messages: 7
Registered: August 1993

Junior Member

In article <28csjc$qde@news.aero.org> rdavis@aerospace.aero.org
(Robert Davis) writes:
> I am trying to read a data file containing an unknown amount of data into
> arrays in IDL. I know the format of the data in the file, but not the number
> of pieces of data in the file. Currently, I read the file twice; once to
> determine the amount of data in the file and then a second time to actually
> read the data into an array (now that I know the size of array needed).
> Is there a better way to do this (without having to read the file twice)?
>
> Robert Davis
> Member of Technical Staff
> The Aerospace Corporation
> rdavis@aero.org
>
I assume your data file does not have a header
which contains the information you need. If the file has fixed-length
records, you could probably deduce the number of entries from the file
size. You can get the file size using FSTAT. On a Unix box you'll get
the size in bytes, which should get you to the number of records fairly
accurately. If you are running under VMS, the result might only be
good to the nearest multiple of 512 bytes.

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[Message index]

		Re: Reading files with unknown amount of data By: pendleton on Thu, 04 November 1993 09:46
		Re: Reading files with unknown amount of data By: alans on Thu, 04 November 1993 08:09
		Re: Reading files with unknown amount of data By: zawodny on Thu, 04 November 1993 04:44
		Re: Reading files with unknown amount of data By: brau1231 on Thu, 04 November 1993 03:12
		Re: Reading files with unknown amount of data By: sterne on Thu, 30 September 1993 16:38
		Re: Reading files with unknown amount of data By: zawodny on Thu, 30 September 1993 12:27
		Re: Reading files with unknown amount of data By: pat on Thu, 30 September 1993 10:32
		Re: Reading files with unknown amount of data By: jim on Thu, 30 September 1993 10:47
		Re: Reading files with unknown amount of dat By: oet on Fri, 05 November 1993 00:28

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