Why is `find -depth 1` so slow to list directories?

bash performance find ls
Remi.b picture Remi.b · Jul 26, 2016 · Viewed 10.4k times · Source

I am listing directories in the current directory. Here are the two commands I am comparing:

ls -F | grep /

find . -type d -depth 1

The ls command is quasi instantaneous while the find command takes about 10 seconds. It feels like the find command is going through the content of each subdirectory while it does not seem to be required by the command.

What is find . -type d -depth 1 doing to be so slow?

Answer

Eric Renouf picture Eric Renouf · Jul 27, 2016

-depth does not stop at a single layer, you want -maxdepth for that. Instead it tells find to process the directories contents before itself, i.e., a depth first search.

Try instead

find . -maxdepth 1 -type d

it will find more than ls -F | grep / because it will also search "hidden" files, and for my example it was ever so slightly faster (0.091 seconds compared to 0.1).

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