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Re: Fast editing of text file? [message #44476 is a reply to message #44472]

Wed, 15 June 2005 20:28

Mark Hadfield
Messages: 783
Registered: May 1995

Senior Member

andrew.cool@dsto.defence.gov.au wrote:
>
> If lines[0:10] and lines[12:*] don't change, why not hold those
> permanently
> in memory as two string arrays, array_top and array_bottom.
>
> Concoct Line 12 with your 3 new numbers,
> and then printf to a new version of the file :-
>
> printf,outlun, array_top ; lines 1..11
> printf,outlun, line12 ; line 12
> printf,outlun, array_bottom ; lines 13..end of file
>
> This way you've only got 1 read, at the very start of your program, and
> then 1 write per change of numbers.

It might be that the concatenation of these three components could be
done more quickly by a system command like Unix "cat". In other words
you would have file_top and file_bottom containing the unchanging bits;
IDl would write a new version of file_middle each time, then

spawn, "cat file_top file_middle file_bottom > file"

On the other hand it could be slower...

--
Mark Hadfield "Kei puwaha te tai nei, Hoea tahi tatou"
m.hadfield@niwa.co.nz
National Institute for Water and Atmospheric Research (NIWA)

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[Message index]

		Re: Fast editing of text file? By: R.Bauer on Sun, 19 June 2005 01:12
		Re: Fast editing of text file? By: Craig Markwardt on Thu, 16 June 2005 07:51
		Re: Fast editing of text file? By: Michael Wallace on Thu, 16 June 2005 01:05
		Re: Fast editing of text file? By: Mark Hadfield on Wed, 15 June 2005 20:28
		Re: Fast editing of text file? By: Andrew Cool on Wed, 15 June 2005 19:55
		Re: Fast editing of text file? By: marc schellens[1] on Wed, 15 June 2005 00:55
		Re: Fast editing of text file? By: Michael Wallace on Tue, 14 June 2005 21:22
		Re: Fast editing of text file? By: t_314159 on Tue, 14 June 2005 17:15
		Re: Fast editing of text file? By: Michael Wallace on Tue, 14 June 2005 16:26

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