[erlang-questions] read_file -- binary data object

[Dan Sommers]

On 12/19/18 6:04 PM, Donald Steven wrote:

 > Taking your foo1,txt example, when I read it back
 > (file:read_file("foo1.txt"), how do I access the individual characters
 > of "Something I'll write to disk."  That is, if
 > file:read_file("foo1.txt") yields {ok,<<"Something I'll write to
 > disk.">>}, how do I read the "S", then the "o", etc.?

What is your ultimate intent with all of those individual characters?

(1) If you want to create a new list from them, then convert the binary
to a list and use a list comprehension:

     [operate_on_one_octet(Octet) || Octet <- binary:bin_to_list(Binary)]

or perhaps lists:filter, lists:foldl, lists:map, etc.

(2) If you want to run some side-effect-producing function on each one,
then use lists:foreach:

     lists:foreach(fun print_one_octet(Octet) ->
                       io:format("--> ~p <--~n", [Octet])
                   end,
                   binary:bin_to_list([Binary]))

Dan