While the code has been written with Windows integration in mind and the build files work to create an appropriate .dll attempts to send and receive messages had been resulting in a semaphore error.

This needs to be looked into before any support for windows can be considered

Internally raised issue

The current interface allows a user to connect to a Client using .mqtt.conn which is a wrapper around MQTTClient_connect however there isn't a mechanism to disconnect.

Exposure of the function MQTTClient_disconnect() from the Eclipse C api should allow disconnections to be handled gracefully

https://www.eclipse.org/paho/files/mqttdoc/MQTTClient/html/_m_q_t_t_client_8h.html#a1e4d90c13a3c0705bc4a13bfe64e6525

skip_cleanup was previously giving a config warning - recommended to change to cleanup

For release on another repo it printed
"Cleaning up git repository with git stash --all. If you need build artifacts for deployment, set deploy.skip_cleanup: true. See https://docs.travis-ci.com/user/deployment#Uploading-Files-and-skip_cleanup."
and caused release to fail.

Changing back now gives no warning

Issue with all Linux/OSX/Windows releases, only the .so/.dll is included

./install.sh
Detected System
* OS: linux-gnu
* TYPE: x86_64
* MACHINE TYPE: x86_64-pc-linux-gnu
ERROR: Directory 'lib' does not exist. Please run from release package

$ wget -O mqtt.tar.gz https://github.com/KxSystems/mqtt/releases/download/1.1.0/mqttkdb-linux-1.1.0.tgz
$ tar -tvf mqtt.tar.gz
drwxrwxr-x travis/travis     0 2022-01-07 11:54 ./
drwxrwxr-x travis/travis     0 2022-01-07 11:54 ./lib/
-rwxrwxr-x travis/travis 22688 2022-01-07 11:54 ./lib/mqttkdb.so

This functions as a work around:

wget -O mqtt.tar.gz https://github.com/KxSystems/mqtt/archive/1.1.0.tar.gz
tar -xzf mqtt.tar.gz
cd mqtt-1.1.0
wget -O lib.tar.gz https://github.com/KxSystems/mqtt/releases/download/1.1.0/mqttkdb-linux-1.1.0.tgz
tar -xzf lib.tar.gz
./install.sh

New docs folder wont currently be added to a release build - should be included in the future while docs are there.
.travis.yml example area
e.g.
elif [[ $TRAVIS_OS_NAME == "windows" ]]; then
7z a -tzip $FILE_NAME README.md install.bat LICENSE q examples;
elif [[ $TRAVIS_OS_NAME == "linux" || $TRAVIS_OS_NAME == "osx" ]]; then
tar -zcvf $FILE_NAME README.md install.sh LICENSE q examples;

Running q producer.q, I type '\t 100'.
It prints sending a msg every few ms.
After a while, I type '\t 0' to stop. When I do that, it seems to suddenly prints a big batch of msgs - but using a client at the same time those batch of msgs are never received. Not sure if there were actually sent, since they seem to be printed after doing the cmd to stop the sends.

Looks like a header with size and either 'a','b','c' sent across the connection in order to transmit actions.
Could be a struct with an enum instead
e.g. mqttaction {long size;action_type action)
were action_type is a new enum.
Will make the code easier to read/understand
NOTE: above code is just an example - don't need to use same variable names/etc

Report from user:

I have the interface working on a Raspberry Pi but had some issues following the instructions and using the supplied install.sh
Default kdb+ build from kx comes named q/l32arm . I needed to rename to q/l32
Otherwise error will be seen:
q)\l mqtt.q
'/home/pi/q/l32/mqtt.so: cannot open shared object file: No such file or directory
[2] /home/pi/q/mqtt.q:2: connX :mqtt 2:(connX;3);
^
[0] ()
Install.sh fails
Detected System

• OS: linux-gnueabihf
• TYPE: arm
• MACHINE TYPE: arm-unknown-linux-gnueabihf
  ERROR: OSTYPE linux-gnueabihf not currently supported by this script
  Please view README.md for installation instructions
  Issue 2 can be bypassed with: OSTYPE="linux-gnu" ./install.sh but that shows another error:
  ERROR: Directory 'lib' does not exist. Please run from release package
  The .so is located in the cmake folder

Instead of using install.sh I just did copies manually:
cp q/mqtt.q $QHOME/
cp cmake/mqtt.so $QHOME/l32/

Create travis file for builds on different platforms

Ref:
https://www.eclipse.org/paho/files/mqttdoc/MQTTClient/html/_m_q_t_t_client_8h.html#aaa8ae61cd65c9dc0846df10122d7bd4e
https://www.eclipse.org/paho/files/mqttdoc/MQTTClient/html/struct_m_q_t_t_client__connect_options.html#a9f1cdffc99659fd4e2d20e6de3c64df0

Currently theres a dict for username/password.
Could add other options and document them, that correlate to the options on the above links.

NOTE: different options can have different datatypes

Looks like a message could potentially arrive before the subscription table created (could be altered to setup prior to the event)
https://github.com/KxSystems/mqtt/blob/master/examples/consumer.q

https://eclipse.github.io/paho.mqtt.c/MQTTClient/html/_m_q_t_t_client_8h.html#a9c1c28258f0d5c6a44ff53a98618f5f3
Document, allow to be user configurable if not ideal.

May want to support other options.
Ref:
https://www.eclipse.org/paho/files/mqttdoc/MQTTClient/html/_m_q_t_t_client_8h.html#aaa8ae61cd65c9dc0846df10122d7bd4e
https://www.eclipse.org/paho/files/mqttdoc/MQTTClient/html/struct_m_q_t_t_client__connect_options.html#a9f1cdffc99659fd4e2d20e6de3c64df0

When I tried to connect to the solace mqtt broker, it gave me an error 4.
Temp adding in the following to the 'conn' function allowed it to work (replacing the username/password with my actual user/pass)

conn_opts.keepAliveInterval = 20;
conn_opts.cleansession = 1;
conn_opts.username = " my username ";
conn_opts.password = " my password ";

Could potentially pass in a dict to the function to allow the end user to provide a range of supported options & any addition ones in the future.

newer version has fixes for keep alive
https://github.com/eclipse/paho.mqtt.c/milestone/19?closed=1
example of previous upgrade change
898ab72

For the producer.q - may be handy to print topic being used or provide a topic
Quickly ran the example with the solace subscriber & took a min to figure out the topic I should be subscribing to, in order to see the data.

Example running, just for show:
q producer.q
(msgsent;1) (msgsent;2)
(`msgsent;3)

subscribing to topic2

Message received

payload | "2020.05.07D11:51:58.142589000;topic2_0"
dest | `topic2
isRedeliv| 0b
isDiscard| 0b
isRequest| 0b
sendTime | 2000.01.01D00:00:00.000000000

Message received

payload | "2020.05.07D11:51:58.344448000;topic2_1"
dest | `topic2
isRedeliv| 0b
isDiscard| 0b
isRequest| 0b
sendTime | 2000.01.01D00:00:00.000000000

Various connections options supported e.g.

Build config validation

deploy: deprecated key skip_cleanup (not supported in dpl v2, use cleanup)
root: missing dist, using the default xenial
root: missing os, using the default linux
deploy: key api_key is an alias for token, using token
root: key matrix is an alias for jobs, using jobs

As per KxSystems/solace#156

When trying to build on redhat7.6 it doesn't seem possible (easy) to install cmake3

Clean install

sudo yum install libGL libGLU libX11 vim netstat bind-utils tcpdump lsof telnet
sudo yum install net-tools wget libpng fontconfig zip unzip bzip2 rsync unixODBC
sudo yum install  java-11-openjdk
sudo yum install compat-openssl10
sudo yum install libXcomposite libXcursor libXi libXtst libXrandr alsa-lib mesa-libEGL libXdamage mesa-libGL libXScrnSaver

-- installed Anaconda
./Anaconda3-2022.05-Linux-x86_64.sh

sudo yum install git gcc g++ cmake make vim wget dos2unix autoconf automake libtool

mkdir github
cd github/

sudo yum install git gcc g++ cmake make vim wget dos2unix autoconf automake libtool
sudo yum -y install openssl-devel

git clone https://github.com/KxSystems/mqtt
git clone https://github.com/eclipse/paho.mqtt.c.git
cd paho.mqtt.c/
make
sudo make install
cd ../mqtt/

mkdir build && cd build
cmake ..

(base) [kxlm@kxlmukdev01 build]$ cmake ..
CMake Error at CMakeLists.txt:4 (cmake_minimum_required):
  CMake 3.1 or higher is required.  You are running version 2.8.12.2


-- Configuring incomplete, errors occurred!

(base) [kxlm@kxlmukdev01 build]$ cmake --version
cmake version 2.8.12.2

(base) [kxlm@kxlmukdev01 build]$ sudo yum -y install cmake3
Failed to set locale, defaulting to C
Loaded plugins: langpacks, product-id, search-disabled-repos
Resolving Dependencies
--> Running transaction check
---> Package cmake3.x86_64 0:3.17.5-1.el7 will be installed
--> Processing Dependency: cmake3-data = 3.17.5-1.el7 for package: cmake3-3.17.5-1.el7.x86_64
--> Processing Dependency: librhash.so.0()(64bit) for package: cmake3-3.17.5-1.el7.x86_64
--> Processing Dependency: libuv.so.1()(64bit) for package: cmake3-3.17.5-1.el7.x86_64
--> Processing Dependency: libzstd.so.1()(64bit) for package: cmake3-3.17.5-1.el7.x86_64
--> Running transaction check
---> Package cmake3-data.noarch 0:3.17.5-1.el7 will be installed
--> Processing Dependency: /usr/bin/python3 for package: cmake3-data-3.17.5-1.el7.noarch
---> Package libuv.x86_64 1:1.44.2-1.el7 will be installed
---> Package libzstd.x86_64 0:1.5.2-1.el7 will be installed
---> Package rhash.x86_64 0:1.3.4-2.el7 will be installed
--> Processing Dependency: /usr/bin/python3 for package: cmake3-data-3.17.5-1.el7.noarch
--> Finished Dependency Resolution
Error: Package: cmake3-data-3.17.5-1.el7.noarch (epel)
           Requires: /usr/bin/python3
 You could try using --skip-broken to work around the problem
 You could try running: rpm -Va --nofiles --nodigest

Tried various tests/installs to get python installed but still can't yum install cmake3

cmake --version
  161  sudo yum -y install python3 cmake3 ## No lnonger in 7.6
  162  sudo yum -y install rh-python36 cmake3
  163  sudo yum -y install rh-python36
  164  sudo yum -y install cmake3 ## Still fails
  165  scl enable rh-python36 bash
python3 -V
which python  ## installed in /opt/rh/rh-python36/root/usr/bin/python3

Some work done on #44 - thanks to walshphilip86 - windows not building with change (may be due to pragmas in src for windows)

Ref:
https://www.eclipse.org/paho/files/mqttdoc/MQTTClient/html/struct_m_q_t_t_client___s_s_l_options.html
http://www.steves-internet-guide.com/mosquitto-tls/

Need to check use with and without ssl (and without any installed ssl libs)...may need to create separate client libs.
Various fixes in newer paho mqtt lib - may upgrade also.

Build using libpaho-mqtt3a, paho-mqtt3as, paho-mqtt3c, paho-mqtt3cs - shouldnt need all these.

Ref: https://github.com/eclipse/paho.mqtt.c#libraries

Running without any SSL lib installed (nor wanting to use SSL)...

q ./mqtt/examples/consumer.q
'libssl.so.1.0.0: cannot open shared object file: No such file or directory
  [5]  /mqttq/q/mqtt.q:3: connX:`mqttkdb 2:(`connX;3);

Relates to #44 mentioning use of libs

Add details to README.md on how to run examples & what they do.
Can either add to main README.md or have a link to a new examples/README.md

From main org screen, noticed it wasn't showing up with a license (e.g. apache2)