On 17 July 2013 16:58, Christian Neukirchen <chneukirc...@gmail.com> wrote: > Calvin Morrison <mutanttur...@gmail.com> writes: > >> On 17 July 2013 16:32, Christian Neukirchen <chneukirc...@gmail.com> wrote: >>> Calvin Morrison <mutanttur...@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@ecoli:~/big_folder> time ls file2v1dir/ | wc -l >>>> 687560 >>>> >>>> real 0m7.798s >>>> user 0m7.317s >>>> sys 0m0.700s >>>> >>>> calvin@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@ecoli:~/big_folder> ls 2v1 | wc -l >> 687560 >> >> real 0m7.678s >> user 0m7.313s >> sys 0m0.579s >> >> calvin@ecoli:~/big_folder> time dc 2v1 >> 687560 >> >> real 0m0.138s >> user 0m0.055s >> sys 0m0.082s >> >> calvin@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 <chneukirc...@gmail.com> http://chneukirchen.org > >
time find 2v1 -printf x | wc -c 687561 real 0m0.531s user 0m0.264s sys 0m0.271s time ls 2v1 > /dev/null real 0m7.642s user 0m7.265s sys 0m0.375s So it seems a good deal of that time is ls
