PAHO_C_SUB(1L)

🦋 PAHO_C_SUB — the paho_c_sub(1L) page, bestie edition 🦋

okay so. welcome to the manual for paho_c_sub, from the Paho C crew. pull up a chair, grab a strawberry 🍓, and let's get you subscribed.

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✨ NAME ✨

paho_c_sub — receive (subscribe to) data from an MQTT server 💌

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🌈 SYNOPSIS 🌈

paho_c_sub [topic] [-t|--topic topic] [-c|--connection connection]
[-h|--host hostname] [-p|--port portnumber] [-i|--clientid clientid]
[-u|--username username] [-P|--password password] [-k|--keepalive
keepalive-timeout] [-V|--MQTT-version 31|311|5]
[-q|--qos 0|1|2] [-R|--no-retained] [--delimiter delimiter] [--no-
delimiter]
[--quiet] [--verbose] [--trace min|max|error|protocol]
[--will-topic will-topic] [--will-payload will-payload] [--will-retain]
[--will-qos 0|1|2]
[--cafile cafile] [--capath capath] [--cert certfile] [--key keyfile]
[--keypass password] [--ciphers cipher-string] [--insecure]

no cap, that's the whole vibe right there 👑

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💖 DESCRIPTION 💖

paho_c_sub receives data from an MQTT server using the Eclipse Paho C client asynchronous library (MQTTAsync). MQTT is a protocol, operating over TCP/IP, which allows programs to easily communicate with each other through a server. Messages are published to topics and delivered to any subscribers to those topics. The corresponding publisher program paho_c_pub allows MQTT messages to be sent. it's giving pen pals but for processes 💅

The default mode of operation is to output each message to stdout terminated by the delimiter. simple. iconic. periodt ✨

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🎀 OPTIONS 🎀

so many flags bestie, but every single one is here, i promise 🫶

• -t, --topic — The MQTT topic to publish the data to.
• -c, --connection — The MQTT URI to connect to, a combination of transport prefix, host, port and for websockets, topic. To connect using TCP use the tcp prefix, for example: tcp://localhost:1883. An example using SSL/TLS: ssl://localhost:1883. An example for websockets, insecure: ws://localhost:1883/topic, and secure: wss://localhost:80/topic.
• -h, --host — The TCP/IP host name of the MQTT server to connect to. Along with the --port option, an older alternative to using --connection.
• -p, --port — The TCP/IP port number of the MQTT server to connect to. Along with the --host option, an older alternative to using --connection.
• -q, --qos — The MQTT QoS on which to publish the message. The alternatives are 0, 1 or 2.
• -V, --MQTTversion — The version of the MQTT protocol to use. Valid options are 31 (or mqttv31), 311 (mqttv311) and 5 (or mqttv5).
• --quiet — Do not print error messages.
• --trace — Print library internal trace. Valid levels are min, max, error and protocol.
• -R, --no-retained — Do not print messages which have the MQTT retained flag set.
• --delimiter — The delimiter string to append to each message when printing. Defaults to newline.
• --no-delimiter — Do not add a delimiter to each message when printing.
• --will-topic — Sets the MQTT will message topic to publish to. If the application ends without sending an MQTT disconnect, the will message will be published to this topic.
• --will-payload — Only used if will-topic is set. Sets the MQTT will message to be published.
• --will-qos — Only used if will-topic is set. Sets the MQTT QoS at which the will message is published. The alternatives are 0, 1 or 2.
• --will-retain — Only used if will-topic is set. Sets the MQTT retained flag on the will message.
• --cafile — Only used with a TLS connection. The name of a file for the OpenSSL trust store.
• --capath — Only used with a TLS connection. The name of a directory holding OpenSSL trusted certificates.
• --cert — Only used with a TLS connection. The name of a file for the TLS keystore containing a client certificate to be presented.
• --key — Only used with a TLS connection. The name of a file containing the client private key.
• --keypass — Only used with a TLS connection. The password for the client private key file, if needed.
• --ciphers — Only used with a TLS connection. A list of cipher suites that the client will present to the server during the TLS handshake.
• --insecure — Only used with a TLS connection. Don't check that the server certificate common name matches the hostname.

💀 bestie please read the --insecure one twice. it literally turns off the check that the server cert common name matches the hostname. it's a vibe, but it's a risky vibe. you've been warned 🚨

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and that's the whole page, no skips, no cuts 💜

this lil masterpiece came from http://eclipse.org/paho, dated 31 July 2018, and it's the v1.3.0 era of PAHO_C_SUB(1L). go subscribe to something cute, bestie 🧚✨