[erlang-questions] Issue with my first program

Edwin Fine <>
Thu Sep 4 21:55:22 CEST 2008


dispatchloop is expecting a list but you are giving it a binary.

You probably want something like

dispatchloop(<<>>, Working) ->
    Working;
dispatchloop(<<$#,Rest/bytes>>, Working) ->
    callcommand(Working),
    dispatchloop(Rest, []);
dispatchloop(<<_Skip,Rest/bytes>>, Working) ->
    dispatchloop(Rest, Working).

HTH

On Thu, Sep 4, 2008 at 3:34 PM, Timothy Baldridge <>wrote:

> Well, I'm finally making the dive into Erlang programming. I have
> project at work here that I'm using to learn with. Basically this
> program will connect to a tcp server. Then it will begin to parse info
> that the server spits out. The data is in this format (plaintext):
>
> command|arg1|arg2#command2|arg2#
>
> So # separates commands and | separates phrases. Here's the code I have so
> far:
>
> -module(filemonitor).
> -export([start/1, dispatchloop/2]).
>
> start(Ip) ->
>    {ok, Socket} = gen_tcp:connect(Ip, 9442, [binary]),
>    loop(Socket, []).
>
> loop(Socket, Buffer) ->
>    receive
>        {tcp, Socket, Bin} ->
>            io:format("~p~n", [Bin]),
>            Newbuff = dispatchloop(Bin, Buffer),
>            loop(Socket, Newbuff);
>        {tcp_error, Socket, Reason} ->
>            io:format("Error ~p~n", [Reason]),
>            gen_tcp:close(Socket);
>        {tcp_closed, Socket} ->
>            io:format("Connection Terminated~n")
>    end.
>
>
>
> callcommand(Working) ->
>    io:format("~s~n", [Working]).
>
> dispatchloop([],Working) ->
>    Working;
> dispatchloop([H|T], Working) ->
>    if
>        H == "#" ->
>            callcommand(Working),
>            dispatchloop(T, []);
>        true ->
>            dispatchloop(T, Working)
>    end.
>
>
> I get this error:
>
> 4> filemonitor:start("192.168.101.170").
> <<"getattr|/#">>
> ** exception exit: function_clause
>     in function  filemonitor:dispatchloop/2
>        called as filemonitor:dispatchloop(<<"getattr|/#">>,[])
>     in call from filemonitor:loop/2
>
>
> Any ideas I'm stumped....
>
> Thanks,
>
> Timothy
> _______________________________________________
> erlang-questions mailing list
> 
> http://www.erlang.org/mailman/listinfo/erlang-questions
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://erlang.org/pipermail/erlang-questions/attachments/20080904/2a598b6c/attachment.html>


More information about the erlang-questions mailing list