optimization ?

[HP Wei]

Thank you very much for giving various pointers.
I will pick up the tool fprof.   

I looked at the codes in file.erl in the lib/kernel/src and found
that all system file related operations are done through a file server.
The overhead perhaps explains why this function for extracting
a list of subdirectories is slow (in comparison to python's version
which calls a C-function directly as I understand).

Perhaps, if necessary, I will 
need to  study the foreign language interface in Erlang.

--HP


>According to fprof function spends most time in {file,read_link_info}:

>                             CNT  ACC
>{test,dirs,3}		     1086 2365.887
>{file,read_link_info,1}	     1010 2152.686
>{erlang,'++',2},	     1085 24.044

----------------------
>Anyway, it looks like the real culprit is file:read_link_info