Suggestion: file:is_directory

Raimo Niskanen <>
Mon Jun 17 08:54:26 CEST 2002


I'll put it on the list of things that I *might* be able to squeeze into
R9 to be released this autumn.

/ Raimo Niskanen, Erlang/OTP, Ericsson AB



 wrote:
> 
> I'm finding Erlang to be a great scripting language for things that
> I'd normally use Perl for.  One little addition to the file module
> that would be nice is file:is_dir/1.  file:list_dir/1 is great for
> getting a list of files in a directory, but then to figure out which
> of those are directories and not files themselves is verbose compared
> with Perl:
> 
> -include_lib("kernel/include/file.hrl").
> 
> is_dir(Filename) ->
>         {ok, Info} = file:read_file_info(Filename),
>         Type = Info#file_info.type,
>         case Type of
>                 directory -> true;
>                 _ -> false
>         end.
> 
> Having to bring in the hrl file is doubly ugly; I always have to look
> it up in the docs.  And it's silly to create an entire file_info
> record just to make this check.  This is very common when doing a
> recursive traversal of a directory tree.
> 
> I could probably make a case for file:size and file:exists shortcuts
> as well :)
> 
> (BTW, the R8 docs for file:read_file_info neglect to give the name of
> the file_info record.  You have to look in the hrl file to find the
> name.)



More information about the erlang-questions mailing list