Calvin Morrison <mutantturkey_AT_gmail.com> writes:
> On 17 July 2013 16:32, Christian Neukirchen <chneukirchen_AT_gmail.com> wrote:
>> Calvin Morrison <mutantturkey_AT_gmail.com> writes:
>>
>>> Hi guys,
>>>
>>> I came up with a utility[0] that i think could be useful, and I sent
>>> it to the moreutils page, but maybe it might fit better here. All it
>>> does is give a count of files in a directory.
>>>
>>> I was sick of ls | wc -l being so damned slow on large directories, so
>>> I thought a more direct solution would be better.
>>>
>>> calvin_AT_ecoli:~/big_folder> time ls file2v1dir/ | wc -l
>>> 687560
>>>
>>> real 0m7.798s
>>> user 0m7.317s
>>> sys 0m0.700s
>>>
>>> calvin_AT_ecoli:~/big_folder> time ~/bin/dc file2v1dir/
>>> 687560
>>>
>>> real 0m0.138s
>>> user 0m0.057s
>>> sys 0m0.081s
>>>
>>> What do you think?
>>> Calvin
>>
>> What's the bottle neck here?
>
> Looking up the filenames and reading them, printing them to standard
> out and then wc parsing for all the \n characters.
>
>> (Or is your dc only faster because the directory index is in cache now...)
>
> No that's not why:
>
> calvin_AT_ecoli:~/big_folder> ls 2v1 | wc -l
> 687560
>
> real 0m7.678s
> user 0m7.313s
> sys 0m0.579s
>
> calvin_AT_ecoli:~/big_folder> time dc 2v1
> 687560
>
> real 0m0.138s
> user 0m0.055s
> sys 0m0.082s
>
> calvin_AT_ecoli:~/big_folder> time ls 2v1 | wc -l
> 687560
>
> real 0m7.672s
> user 0m7.310s
> sys 0m0.580s
How fast is find 2v1 -printf x | wc -c ?
--
Christian Neukirchen <chneukirchen_AT_gmail.com> http://chneukirchen.org
Received on Wed Jul 17 2013 - 22:58:12 CEST