programming erlang ch6 - andstudy/forge GitHub Wiki

    > code:get_path().
    > code:add_patha(Dir).
    > code:add_pathz(Dir).
    > code:all_loaded().
    > code:clash().
    -----------------------------------------------------
    $ erl -pa Dir1 -pa Dir2 ... -pz DirK1 -pz DirK2

    -module(hello).
    -export([start/0]).
    
    start() ->
        io:format("Hello world~n").

    [bt22d@fog:/user1/bt22d/STUDY/erlang 11 ] erl
    Erlang (BEAM) emulator version 5.6.3 [source] [smp:4] [async-threads:0] [hipe] [kernel-poll:false]
    
    Running Erlang DIR(erlang)
    Eshell V5.6.3  (abort with ^G)
    1> c(hello).
    {ok,hello}
    2> hello:start().
    Hello world
    ok

    [bt22d@fog erlang]$ erlc hello.erl
    [bt22d@fog erlang]$ erl -noshell -s hello start -s init stop
    Hello world
    [bt22d@fog erlang]$

    #!/usr/bin/env escript
    
    main(_) ->
        io:format("Hello world\n").

    [bt22d@fog erlang]$ chmod u+x hello
    [bt22d@fog erlang]$ ./hello
    Hello world
    [bt22d@fog erlang]$

    -module(fac1).
    -export([main/1]).
    
    main([A]) ->
        I = list_to_integer(atom_to_list(A)),
        F = fac(I),
        io:format("factorial ~w = ~w~n",[I, F]),
        init:stop().
    
    fac(0) -> 1;
    fac(N) -> N*fac(N-1).

    # leave these lines alone
    .SUFFIXES: .erl .beam .yrl
    
    .erl.beam:
        erlc -W $<
    
    .yrl.erl:
        erlc -W $<
    
    ERL = erl -boot start_clean
    
    # 컴파일 하려는 얼랭 모듈들의 목록
    # If the modules don't fit onto one line add a \ character
    # to the end of the line and continue on the next line
    
    # Edit the lines below
    MODS = module1 module2 \
           module3 ... special1 ...\
           ...
           moduleN
    
    # The first target in any makefile is the default target.
    # If you just type "make" then "make all" is assumed (because
    #   "all" is the first target in this makefile)
    
    all: compile
    
    compile: ${MODS:%=%.beam} subdirs
    
    ## special compilation requirements are added here
    
    special1.beam: special1.erl
        ${ERL} -Dflag1 -W0 special1.erl
    
    ## run an application from the makefile
    
    application1: compile
        ${ERL} -pa Dir1  -s application1 start Arg1 Arg2
    
    # the subdirs target compiles any code in
    # sub-directories
    
    subdirs:
        cd dir1; make
        cd dir2; make
        ...
    
    # remove all the code
    
    clean:
        rm -rf *.beam erl_crash.dump
        cd dir1; make clean
        cd dir2; make clean

    [bt22d@fog:/user1/bt22d 49 ] erl -pa "/user1/bt22d/STUDY/erlang"
    Erlang (BEAM) emulator version 5.6.3 [source] [smp:4] [async-threads:0] [hipe] [kernel-poll:false]
    
    Running Erlang
    Eshell V5.6.3  (abort with ^G)
    1> code:clash().
    ** /user1/bt22d/STUDY/erlang/a.beam hides ./a.beam
    ** Found 1 name clashes in code paths
    ok
    2>

    2> help().
    ** shell internal commands **
    b()        -- display all variable bindings
    e(N)       -- repeat the expression in query <N>
    f()        -- forget all variable bindings
    f(X)       -- forget the binding of variable X
    h()        -- history
    ...