Idiom for shelling out to $EDITOR/$PAGER?

Steven D'Aprano steve+comp.lang.python at pearwood.info
Fri Dec 23 04:44:31 EST 2011


On Fri, 23 Dec 2011 09:28:52 +0100, Peter Otten wrote:

>> -proper & efficient detection of file-change, to know whether the user
>> actually did anything
> 
> Just read the whole thing back into memory and compare the string to the
> original data. The file has to be quite long for the checksum
> calculation to be worthwhile.

I don't think so. No matter how long the file is, the checksum is always 
going to do far more work than a simple string comparison. A string 
comparison can short-circuit on the first difference; the checksum must 
always process both files in their entirety.


-- 
Steven



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