Proposal: File.lstat and File.lstat! or File.stat(path,:read_link)

[Booker Bense]

Currently when there is a symlink pointing to a non-existant file, 

File.stat!(symlink) 

fails. I think this is the "right" think as it is the same result that you would get from the unix stat call or erlang's :read_file_info.

However, there is no Elixir interface to lstat or erlang :read_link_info. 

Adding File.lstat  and File.lstat! seem like the most obvious options, but you could also add an option to File.stat 

similar to the :time option ( i.e. :read_link that switches it to use :read_link_info ) 

I'm willing to write either; adding the :read_link option seems more "elixir" to me, but I don't have a strong opinions about which is "right".

- Booker C. Bense 

[José Valim]

Great suggestion. Let's go with lstat and lstat!.

José Valim

www.plataformatec.com.br

Skype: jv.ptec

Founder and Lead Developer

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[Booker Bense]

Okay, I have a related question. I had a go at implementing the :read_link option last night and 

this code failed. 

if( Keyword.has_key?(opts,:read_link), 

      do: read_info = F.read_link_info , 

      else: read_info = F.read_file_info

case read_info.((IO.chardata_to_string(path), opts) do

but this code worked. 

if( Keyword.has_key?(opts,:read_link), 

      do: read_info = F.read_link_info(IO.chardata_to_string(path), opts) , 

      else: read_info = F.read_file_info(IO.chardata_to_string(path), opts) )

case read_info do

The error message was 

==> elixir (compile)

** (UndefinedFunctionError) undefined function: :file.read_file_info/0

My best guess is that something different is required when matching a direct erlang functions to a variable, since the . convention

doesn't seem to work in this case. What's the right way to call an erlang function to matched to a variable? 

thanks, 

- Booker C. Bense 

[Paulo Almeida]

In the VM a function is identified by both name and arity.

You need to use the & operator to specify you want to capture the function, not call it.

Use read_info = &F.read_link_info/1

[Paulo Almeida]

Noticed the arity is actually 2, so that would be &F.read_file_info/2

[Booker Bense]

Doh!, obvious now that you point it out. I've gotten to used to simply assigning anonymous functions to variables. 

thanks, 

- Booker C. Bense