Starting Erlang

[Ulf Wiger]

On Wed, 24 Apr 2002, Joe Armstrong wrote:

>Does *anybody* understand (I mean *really* understand the Erlang
>start-boot sequence). Is all this junk in the .script files
>really necessary.

I think I understand at least some of it.
And I have a serious gripe:
You cannot patch .app files, as they are read at installation
time and then copied into the boot script.

If, for example, you'd want to add an application dependency or
an included application -- or do something trivial as updating
the description field -- you must reinstall the system or perform
a full software upgrade. By contrast, changes to an erlang module
can be easily inserted as a patch into the system. "Patching" the
boot script by recompiling it in place really breaks the release
handling structure -- you are clearly not supposed to do things
like that.

One idea I've had is that the .app file attributes should become
callbacks in the application behaviour instead. I have not yet
convinced myself that it's the best solution, but I'm working on
it.


>Do you think there would be any objections if I reworked it all?

Well... I'd say that all the usual objections probably apply (:
(Don't let that deter you from exploring the matter, though.)


>Does anybody write their own .script files and make their own
>home rolled .boot files? - If so please mail me privatly.

I have mailed you privately. (:


/Uffe

-- 
Ulf Wiger, Senior Specialist,
   / / /   Architecture & Design of Carrier-Class Software
  / / /    Strategic Product & System Management
 / / /     Ericsson Telecom AB, ATM Multiservice Networks