[bug-diffutils] bug#20250: bug#20250: diff by size

[Jim Meyering]

On Sun, May 8, 2016 at 9:36 PM, Jim Meyering <address@hidden> wrote:
> tags 20250 notabug
> close 20250
> done
>
> On Fri, Apr 3, 2015 at 6:20 AM, Andreas <address@hidden> wrote:
>> Dear diff-team,
>>
>> this is not a bug but an idea for a diff option in further versions:
>>
>> Idea:
>> comparison of two files by size only.
>>
>> why?
>> makes comparison extremely fast; often no need to compare file contents
>> to get a first hint whether there is a difference at all
>>
>> example:
>> - uploading a folder with a bunch of files to a slow motion cloud;
>> comparing each file by contents is very time consuming (...slow motion
>> cloud)
>> - as a first hint to find out about a possible difference could be the
>> comparison of file size for each file uploaded with the local ones
>
> Thanks for the suggestion, but diff already performs the optimization,
> when possible, of detecting when two files have different sizes,
> and in that case does not even bother to open
> (much less read/compare) them.

To clarify: the above is what happens when you use the --brief (-q) option.
It is obviously not the default.