A pipe opened to mosquitto_sub cannot be closed from the script that opened it

[fuxoft]

I wrote a Lua script (for Linux) that opens a pipe to "mosquitto_sub" and reads incoming data from it. This works flawlessly. But when the script ends and I want to cleanly close the pipe, my script hangs indefinitely on the "fd:close()" line. I am not sure if this is a mosquitto_sub problem but I am using Lua pipes to read outputs of various CLI commands all the time and I have never experienced this behavior before - fd:close() should never hang.

This Lua script shows that closing a pipe to another command works OK but attempt to close a pipe to mosquitto_sub hangs. This script requires local mosquitto server running with default configuration so that the script can connect to it without authentication.

#!/usr/bin/env lua
local fd

print("Opening cat pipe")
fd = io.popen("cat /dev/null")
print("Trying to close cat pipe")
fd:close()
print("Closed cat pipe")

print("Opening mosquitto_sub pipe")
fd = io.popen("mosquitto_sub -t 'nonexistent_topic'")
print("Trying to close mosquitto_pub pipe")
fd:close()
print("Closed mosquitto_pub file") --This is never printed

[ralight]

Thank you, that is now fixed in the fixes branch.