Add workaround for long keys= in mqtt-publisher

docs/src/man/man1/mqtt-publisher.1.adoc

@@ -36,9 +36,15 @@ debian this is available from the `python3-paho-mqtt` package.
 
 == OPTIONS
 
-**keys=**__pin1_[,_pin2_,...]_::
-  The name of HAL pins, signals and other values to publish using MQTT.
-  The names are also used as the JSON keys in the MQTT message published with the broker.
+*keys*=_pin1[,pin2,...]_::
+
+    The name of HAL pins, signals and other values to publish using
+    MQTT.  The names are also used as the JSON keys in the MQTT
+    message published with the broker.
+
+    NOTE: HAL lines are truncated to 255 characters. To work around this
+    limit with long lists of keys, use multiple keys= tokens. The lists
+    will be merged. 
 
 *--dryrun*::
   Do not set up MQTT connection, only print message to stdout.
@@ -84,27 +90,28 @@ The loop reading HAL values and publishing MQTT messages.
 
 == EXAMPLE
 
-Any set of HAL pins and signals can be published.
-This setup might be a useful starting point:
-
-----
-loadusr -W mqtt-publisher [MQTT]DRYRUN --mqtt-broker=[MQTT]BROKER
-  --mqtt-user=[MQTT]USERNAME --mqtt-password=[MQTT]PASSWORD
-  keys=halui.axis.a.pos-feedback,halui.axis.b.pos-feedback,
-  halui.axis.c.pos-feedback,halui.axis.u.pos-feedback,
-  halui.axis.v.pos-feedback,halui.axis.w.pos-feedback,
-  halui.axis.x.pos-feedback,halui.axis.y.pos-feedback,
-  halui.axis.z.pos-feedback,halui.estop.is-activated,
-  halui.joint.0.is-homed,halui.joint.1.is-homed,halui.joint.2.is-homed,
-  halui.joint.3.is-homed,halui.joint.4.is-homed,halui.joint.5.is-homed,
-  halui.joint.6.is-homed,halui.joint.7.is-homed,halui.joint.8.is-homed,
-  halui.machine.is-on,halui.max-velocity.value,halui.mode.is-auto,
-  halui.mode.is-manual,halui.mode.is-mdi,halui.mode.is-teleop,
-  halui.program.is-running'
-----
-
-Note: The list of keys can not include space after comma.
-      The lines are appear broken only to avoid too long lines in the documentation.
+Any set of HAL pins and signals can be published.  This setup might be
+a useful starting point:
+
+  loadusr -W mqtt-publisher [MQTT]DRYRUN --mqtt-broker=[MQTT]BROKER
+      --mqtt-user=[MQTT]USERNAME --mqtt-password=[MQTT]PASSWORD
+      keys=halui.axis.a.pos-feedback,halui.axis.b.pos-feedback,
+      halui.axis.c.pos-feedback,halui.axis.u.pos-feedback,
+      halui.axis.v.pos-feedback,halui.axis.w.pos-feedback,
+      halui.axis.x.pos-feedback,halui.axis.y.pos-feedback,
+      halui.axis.z.pos-feedback keys=halui.estop.is-activated,
+      halui.joint.0.is-homed,halui.joint.1.is-homed,halui.joint.2.is-homed,
+      halui.joint.3.is-homed,halui.joint.4.is-homed,halui.joint.5.is-homed,
+      halui.joint.6.is-homed,halui.joint.7.is-homed,halui.joint.8.is-homed
+      keys=halui.machine.is-on,halui.max-velocity.value,halui.mode.is-auto,
+      halui.mode.is-manual,halui.mode.is-mdi,halui.mode.is-teleop,
+      halui.program.is-running
+
+Note, the list of keys cannot include space after comma.  The lines
+are only broken here to avoid too long lines in the documentation.
+
+HAL limits option length to 255 characters. To work around this multiple keys=
+options can be used if necessary.
 
 == SEE ALSO
 

src/hal/user_comps/mqtt-publisher.py

@@ -116,7 +116,7 @@ def usage():
     @staticmethod
     def main():
         from optparse import Option, OptionParser
-        keys={}
+        keys=[]
         options = [
             Option( '--dryrun', dest='dryrun', action='store_true',
                     help='Dryrun, only collect HAL pin values, do not send them to MQTT.'),
@@ -147,7 +147,7 @@ def main():
 
         for extra in args:
             if 0 == extra.find('keys='):
-                keys = extra.split('=')[1].split(',')
+                keys.extend(extra.split('=')[1].split(','))
 
         h = LinuxCNC2MQTT(opts.mqttbroker, opts.mqttport, opts.mqttprefix,
                           opts.mqttuser, opts.mqttpassword, dryrun=opts.dryrun)