I have an UPS which have a proprietary protocol, so my only option is to take their 8-year old 32bit program and pipe it through an awk-script. ups_status produces a screen like this every two seconds or so.
----------===-----Welcome to ups_manager System!-----===-----
Copyright(C) 2004 Richcomm Technologies, Inc. May 16 2013 ver 1.1
+-----------------------------------------------------------------------------+
| UPS Factory: UPS Model: UPS Version: |
|---------------------------------++------------------------------------------|
| UPS Type : StandBY || UPS Input Voltage: 227.00 Volt |
| UPS Rating Voltage : 220.00 Volt|| |>>>>>>>>>>>>>>>>>>>>>>>-|----|----|----|
| UPS Rating Current : 3.00 || 180 190 200 210 220 230 240 250 |
| UPS Line Frequency : 50.00 Hz || |
| Communication Port : 2 || UPS Output Voltage: 229.00 Volt |
| || |>>>>>>>>>>>>>>>>>>>>>>>>|----|----|----|
| Input AC Power : Normal || 180 190 200 210 220 230 240 250 |
| Battery Status : Normal || |
| UPS Status : Normal || UPS Power Loading: 18.00 |
| Boost/Buck : Buck || |>>>>|----|----|----|----|----|----|----|
| UPS Temperature: 30.80 || 0 20 40 60 80 100 120 140 |
| UPS Self-Test : Normal || |
| Beeper Status : ON || UPS Battery Level: 100.00 |
| || |>>>>>>>>>>>>>>>>>>>>>>>>>----|----|----|
| || 0 20 40 60 80 100 120 140 |
| || |
| || UPS Input Frequency : 49.00 Hz |
| ACfail Shutdown Delay : 3600 s || |>>>>>>>>>>>>>>>>>>>>>>>>|----|----|----|
| UPS Turn Off Delay : 2 min|| 0 10 20 30 40 50 60 70 |
+---------------------------------++------------------------------------------+
I do ups_status | awk -f parseUPS.awk
parseUPS.awk parse the values and produce a json-string (named out) and do
/Turn Off/ {
out=sprintf(....);
print out | "mosquitto_pub -h mqtt.local.net -t ups -l"
}
This works for a day or so, then mosquitto_pub switches to returning 4, invalid user or password.
If I restart the command, it functions correctly.
What could be happening?
Also could I capture the errorcode from the pipe, exit awk and put the line into a do while true -loop?
Ed Morton pointed me in the right direction of putting mosquitto_pub in the pipe instead of in awk.
I tried ups_status |gawk -f parse.awk|mosquitto_pub -h mqtt.local.net -t ups2 -l
This only gave output to mqtt after 4096 characters.
Aha, buffering. So I added fflush("/dev/stdout"); after the printf in awk
This resulted in the output came two lines at a time. Cause: buffering between ups_status and awk.
The unbuffer-command from the expect package solved that.
Final command:
unbuffer ups_status |gawk -f parse.awk|mosquitto_pub -h mqtt.local.net -t ups2 -l
This gives a nice mqtt-message every 3 seconds.