How to use the Jungerl

Simple! You just do 'make' to build all the erlang programs.

If you want, you can add the bin/ directory to your $PATH, and use the useful programs in there. One is 'jerl', a simple wrapper around 'erl' that adds all the Jungerl applications to the code path.

If a program is giving you trouble, just put an empty file called SKIP in its top-level directory. For example, if you want to skip the 'tuntap' program, you can do: touch lib/tuntap/SKIP

If you want to compile only one program or library, you can just do 'make conf' and then type make in the lib/PROGRAMNAME directory of your choice.

How to add an application to the Jungerl

Each application has its own directory called lib/.

The absolute minimum requirement for an application is to have a Makefile in the lib/ directory with two targets:

'all' should build the program.

'clean' should delete any object files.

Realistically, your lib// dir should also have any of these subdirectories that are appropriate:

src/ containing erlang sources

ebin/ for putting compiled beam files

c_src/ containing C sources

priv/ containing files you want at runtime (e.g. built from c_src)

doc/ (not sure what this is for..)

Once you have created your application, you should edit the 'lib/' directory Makefile like this:

Add your to the "LIBS" variable.

If you depend on other applications, add a line that says so. (These are down near the bottom.)

Note that Applications in the Jungerl should be compatible with the latest released version of Erlang/OTP!

Makefile Helpers

The support/ directory contains a couple of useful include files for your Makefiles:

subdirs.mk: Intended for your lib// directory, this defines targets for 'all' and 'clean' that just cd into $(SUBDIRS) (by default c_src and src) and does the same "make" in each of them.

include.mk: This defines a bunch of useful things for building C and Erlang programs. For C it has 'configure'-detected CC and CFLAGS variables, and ERL_C_INCLUDE_DIR for /lib/erlang/usr/include/ (e.g. for writing drivers)

For Erlang it has a 'configure'-detected ERLC, an
automatically-detected list of beam files to build (../ebin/*.beam
for all *.erl files) called ERL_OBJECTS, and
automatically-detected list of headers they depend on (*.hrl and
../include/*.hrl) called ERL_HEADERS, and an implicit rule for
building ../ebin/*.beam from *.erl.

That probably wasn't very clear, but if you look at how the 'tuntap' program's Makefiles are done then it should be obvious!