======
Erlang
======

Erlang is not your typical programming language, see:

  <https://en.wikipedia.org/wiki/Erlang_(programming_language)>

Running the tests: see:

 * ``HOWTO/TESTING.md`` in the source package,
 * https://github.com/erlang/otp/blob/15e2cf7d13ca66d024c3ca948a8ee2475e8acac0/HOWTO/TESTING.md
   (Erlang 22/buster)

.. code-block:: bash

  debuild
  export ERL_TOP=`pwd`
  ./otp_build tests

  cd release/tests/test_server
  erl -s ts install -s init stop

  # all tests (several hours)
  erl -s ts install -s ts run all_tests -s init stop

  # one module (asn1):
  erl
  1> ts:run(asn1, [batch]).

  # SSH requires port 22
  service ssh stop
  erl
  1> ts:run(ssh, [batch]).

  # It also has many errors in buster and stretch (even before ELTS)
  # Individual suites may work better
  1> ts:run(ssh, ssh_connection_SUITE, [batch]).
  2> ts:run(ssh, ssh_protocol_SUITE, [batch]).
  3> ts:run(ssh, ssh_protocol_SUITE, early_rce, [batch]).

  # quit
  2> <Ctrl+g> 
  User switch command
   --> q

An HTTP server can help browse the results:

.. code-block:: bash

  python3 -m http.server --bind 0.0.0.0 8080

The following should work but doesn't; `Failed to start CTH, see the
CT Log for details`, except there's no explanation in the CT Log.

.. code-block:: bash

  mkdir out
  ct_run -logdir out/ -suite lib/ssh/test/ssh_algorithms_SUITE.erl
  # error

  cd release/tests/test_server/
  $ERL_TOP/bin/ct_run -suite ../compiler_test/andor_SUITE -case t_orelse
  # error

Manual SSH testing:

  * ``lib/ssh/doc/src/using_ssh.xml``
  * https://www.erlang.org/doc/apps/ssh/using_ssh.html
  * Needs *RSA PRIVATE KEY* (``ssh-keygen -m pem``),
    not the newer *OPENSSH PRIVATE KEY*
  * There are some errors in the doc (missing commas, etc.)

| Copyright (C) 2025  Sylvain Beucler