[erlang-questions] Can werl be detached?

Daniel Goertzen <>
Wed May 25 22:30:26 CEST 2016

I have a windows app (also on R15) and this is the shortcut that launches

Target: "C:\Program Files (x86)\myprogram\erlang\erts\bin\werl.exe"
-detached -smp enable -run bootstrap"

Start in: "C:\Program Files (x86)\myprogram\erlang\erts\bin"

So, try changing the current directory first to erts/bin before running

On Tue, May 17, 2016 at 6:47 PM John R. Ashmun <>

> Perhaps my subject is not quite the correct question.  Here's my context:
> I'm beginning to recreate in Erlang on Microsoft Windows 10 a public
> domain program I used to enjoy on my Commodore Amiga:  mATC was a game in
> which the user acted as a military Air Traffic Controller.  I am using a wx
> window to draw the player's map with aircraft data blocks overlaid.  I
> don't have a use for the initial window that opens when werl is started.
> http://erlang.org/doc/man/werl.html
> says, in part, "All flags except -oldshell work as they do for the erl
> <http://erlang.org/doc/man/erl.html> command."  I don't have a UNIX-y
> system available to me to learn how they work for the erl command.  (The
> erl command as an interactive program is iffy in a Windows Command Prompt
> window.)
> In particular, the description of -detached in
> http://erlang.org/doc/man/erl.html
> would seem to be what I want:
> "Starts the Erlang runtime system detached from the system console. Useful
> for running daemons and backgrounds processes. Implies -noinput."
> I want the Erlang VM to run my game without an Erlang shell's having
> opened a window, and I want my game to be in control of its wx window.
> Further, following what I think I learned from "Erlang and OTP in Action",
> I have an OTP application being started by a boot file created from a .rel
> file.  All of this is in the setting of an ancient Erlang release:  R15B.
> If I use this Command Prompt batch file, mATC.bat:
> werl -pa ebin -pa mATC_app\ebin -detached -boot mATC -config sys
> a Windows error message window appears that says:
> "Failed to execute C:\Program Files\erl5.9\erts5.9\bin\beam.smp.dll
>  The system cannot find the file specified."
> The DLL is actually present at that location, and of course everything
> runs well when I don't use -detached.
> Please advise.
> Regards,
> John Ashmun
> _______________________________________________
> erlang-questions mailing list
> http://erlang.org/mailman/listinfo/erlang-questions
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://erlang.org/pipermail/erlang-questions/attachments/20160525/b8f92659/attachment.html>

More information about the erlang-questions mailing list