Here is an example of an erlang program:
<![CDATA[%%%----------------------------------------------------------------------
%%% File : count_chars.erl
%%% Author : Claes Wikstrom <klacke@erix.ericsson.se>
%%% Purpose : Count the x chars in a file
%%% Created : 20 Oct 1998 by Claes Wikstrom <klacke@erix.ericsson.se>
%%%----------------------------------------------------------------------
-module(count_chars).
-author('klacke@erix.ericsson.se').
-export([file/1, file1/1, file2/1]).
file(Fname) ->
case file:open(Fname, [read, raw, binary]) of
{ok, Fd} ->
scan_file(Fd, 0, file:read(Fd, 1024));
{error, Reason} ->
{error, Reason}
end.
scan_file(Fd, Occurs, {ok, Binary}) ->
scan_file(Fd, Occurs + count_x(Binary), file:read(Fd, 1024));
scan_file(Fd, Occurs, eof) ->
file:close(Fd),
Occurs;
scan_file(Fd, _Occurs, {error, Reason}) ->
file:close(Fd),
{error, Reason}.
%% Count the number of 'x' chars in a binary
count_x(Bin) ->
count_x(binary_to_list(Bin), 0).
count_x([$x|Tail], Ack) ->
count_x(Tail, Ack+1);
count_x([_|Tail], Ack) ->
count_x(Tail, Ack);
count_x([], Ack) ->
Ack.
file1(File) ->
F = fun(Bin, Int) ->
{more, count_x(Bin) + Int}
end,
klib:with_file(File, F, 0).
file2(File) ->
{ok,B} = file:read_file(File),
lists:foldl(fun($x, Ack) ->
1 + Ack;
(_, Ack) ->
Ack
end, 0, binary_to_list(B)).
]]>
Erlang is a well known and fun programming language to learn. We should further study this language, so that we can get some type of understanding how languages differ from each other.
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