[erlang-questions] Identifying modules to load in a release file

Zoltan Lajos Kis <>
Sat Dec 19 19:29:15 CET 2009


Doug Fort wrote:
>
>
> On Sat, Dec 19, 2009 at 1:16 PM, Zoltan Lajos Kis < 
> <mailto:>> wrote:
>
>     All modules should be be grouped into applications. Mnesia is an
>     application, however ets is just a module: it is part of the
>     stdlib application.
>
>     Each application has a .app file (usually in the ebin dir) that
>     tells the version of the application and lists other applications
>     it depends on.
>     Basically if you ever have an application:start(App) in your
>     sources, it should go here.
>     An example my_app.app, that shows the app is version 0.1, and
>     depends on four applications:
>
>     {application, my_app,
>      [{description, "My Application"},
>       {vsn, "0.1"},
>       ...
>       {applications, [mnesia, sasl, stdlib, kernel]},
>       ...
>      ]
>     }.
>
>     Based on these files you should be able to gather the list of all
>     applications you would like to start, and applications they depend on.
>
>
> How do I find the applications they depend on? That's my real 
> question. I have an application that works fine in interactive mode, 
> but one of its event handlers doesn't work right in embedded mode. I 
> assume there's something I'm failing to load, but I am anumable to 
> tell what it is from the documentation.
That should result in an undefined function error for the module which 
is not loaded.
Run code:which(Module). in interactive mode; that should point you to 
the application.
>
>
>  
>
>     You can get the version of each application from the .app file (or
>     from the directory name).
>     So the 0.1 release of my_thing for R13B03 should look like:
>
>     {release, {"my_thing", "0.1"}, {erts, "5.7.4"},
>      [{my_app, "0.1"},
>       {mnesia, "4.4.12"},
>       {sasl, "2.1.8"},
>       {stdlib, "1.16.4"},
>       {kernel, "2.13.4"}
>      ]
>     }.
>
>     Regards,
>     Zoltan.
>
>     PS.: I guess kernel and stdlib is started anyway, so you don't
>     need to explicitly list them. It probably doesn't make any harm
>     though.
>
>
>     Doug Fort wrote:
>
>         How can one identify which library modules to put in the .rel
>         file? For
>         example, if a process uses the ets term storage, you must add
>         {mnesia,
>         "4.4.12"} to the release file. I suspect I'm missing something
>         obvious, but
>         I haven't found a straightforward way determine this.
>
>          
>
>
>
>
>
> -- 
> Doug Fort, Consulting Programmer
> http://www.dougfort.com



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