Comparing version 8 and version 7 back

h1. Random Erlang Pieces of Code

See also:
* [[erlangconnect|Interconnecting Erlang Nodes]]

h2. Add directory to the binaries search path

Add these lines to your _~/.erlang_

code:add_path("/ebin").
code:add_path("/ebin").


h2. Working on the remote node

h3. Open a shell

pr@local> {Press Ctrl+G}
User switch command
 --> j
   1* {shell,start,[init]}
 --> r 'dummy@remote'
 --> j
   1  {shell,start,[init]}
   2* {dummy@remote,shell,start,[]}
 --> c 2
Eshell V5.5.4  (abort with ^G)
(dummy@remote)1> 


h3. Spawn a process

remote$ % cat dummy.erl
-module(dummy).
-export([loop/0]).

loop() ->
  receive
    {Node, Msg} ->
       io:format("~s : ~s~n", [Node, Msg]),
       loop();
     _ -> io:format('not defined~n')
  end.

remote$ erl -sdummy
dummy@remote> c(dummy).

local$ erl -sname hello
hello@local> Node = 'dummy@remote'.
hello@local> net_adm:ping(Node).
%% Format: Pid = spawn(Node, mod_name, func_name, [arg1,arg2]).
hello@local> Pid = spawn(Node, dummy, loop, []).
hello@local> Pid ! {self(), 'Hello'}.


h3. Call a procedure

hello@local> rpc:call('dummy@remote', dummy, some_func, [10, arg2]).


h2. Convert command line argument to integer

-module(dummy).
-export([main/1]).

main([Arg|_]) ->
  Val = list_to_integer(atom_to_list(Arg)),
  ...

host$ erl -noshell -s dummy main 1000 -s init stop 


h2. String2Pid

1> self().
<0.29.0>
2> list_to_pid("<0.29.0>") ! hello.


h2. for(1,N,Fun) cycle (repeat some function N times)

for(N, N, _) -> done;
for(N, J, Fun) -> Fun(J), for(N, J+1, Fun).