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https://github.com/zacharyvoase/zmqc

netcat for ØMQ. Small but powerful.
https://github.com/zacharyvoase/zmqc

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netcat for ØMQ. Small but powerful.

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README 

        
# zmqc



zmqc is a small but powerful command-line interface to [ØMQ][zmq]. It allows

you to create a socket of a given type, bind or connect it to multiple

addresses, set options on it, and receive or send messages over it using

standard I/O, in the shell or in scripts. It's useful for debugging and

experimenting with most possible network topologies.



  [zmq]: http://www.zeromq.org/



## Installation



    pip install zmqc



## Usage



    zmqc [-h] [-v] [-0] [-r | -w] (-b | -c) SOCK_TYPE [-o SOCK_OPT=VALUE...] address [address ...]



### Mode





  


    Whether to read from or write to the socket. For PUB/SUB sockets, this

    option is invalid since the behavior will always be write and read

    respectively. For REQ/REP sockets, zmqc will alternate between reading and

    writing as part of the request/response cycle.

  



  
-r, --read


    
Read messages from the socket onto stdout.



  
-w, --write


    
Write messages from stdin to the socket.





### Behavior





  
-b, --bind


    
Bind to the specified address(es).


  
-c, --connect


    
Connect to the specified address(es).





### Socket Parameters





  
SOCK_TYPE


  


    Which type of socket to create. Must be one of `PUSH`, `PULL`, `PUB`,

    `SUB`, `REQ`, `REP` or `PAIR`. See `man zmq_socket` for an explanation of

    the different types. `DEALER` and `ROUTER` sockets are currently

    unsupported.

  


  
-o SOCK_OPT=VALUE, --option SOCK_OPT=VALUE


  


    Socket option names and values to set on the created socket. Consult `man

    zmq_setsockopt` for a comprehensive list of options. Note that you can

    safely omit the `ZMQ_` prefix from the option name. If the created socket

    is of type `SUB`, and no `SUBSCRIBE` options are given, the socket will

    automatically be subscribed to everything.

  


  
address


  


    One or more addresses to bind/connect to. Must be in full ZMQ format (e.g.

    `tcp://:`)

  



## Examples



    zmqc -rc SUB 'tcp://127.0.0.1:5000'



Subscribe to `tcp://127.0.0.1:5000`, reading messages from it and printing them

to the console. This will subscribe to all messages by default (you don't need

to set an empty `SUBSCRIBE` option). Alternatively:



    zmqc -rc SUB -o SUBSCRIBE='com.organization.' 'tcp://127.0.0.1:5000'



This will subscribe to all messages starting with `com.organization.`.



* * * *



    ls | zmqc -wb PUSH 'tcp://*:4000'



Send the name of every file in the current directory as a message from a PUSH

socket bound to port 4000 on all interfaces. Don't forget to quote the address

to avoid glob expansion.



* * * *



    zmqc -rc PULL 'tcp://127.0.0.1:5202' | tee $TTY | zmqc -wc PUSH 'tcp://127.0.0.1:5404'



Read messages coming from a PUSH socket bound to port 5202 (note that we're

connecting with a PULL socket), echo them to the active console, and forward

them to a PULL socket bound to port 5404 (so we're connecting with a PUSH).



* * * *



    zmqc -n 10 -0rb PULL 'tcp://*:4123' | xargs -0 grep 'pattern'



Bind to a PULL socket on port 4123, receive 10 messages from the socket

(with each message representing a filename), and grep the files for

`'pattern'`. The `-0` option means messages will be NULL-delimited rather

than separated by newlines, so that filenames with spaces in them are not

considered two separate arguments by xargs.



* * * *



    echo "hello" | zmqc -c REQ 'tcp://127.0.0.1:4000'



Send the string `hello` through a REQ socket connected to localhost on port

4000, print whatever you get back, and finish. In this way, REQ sockets can

be used for a rudimentary form of RPC in shell scripts.



* * * *



    coproc zmqc -b REP 'tcp://*:4000'

    tr -u '[a-z]' '[A-Z]' <&p >&p &

    echo "hello" | zmqc -c REQ 'tcp://127.0.0.1:4000'



First, start a REP socket listening on port 4000. The `coproc` shell command

runs this as a shell coprocess, which allows us to run the next line, tr. This

will read its input from the REP socket's output, translate all lowercase

characters to uppercase, and send them back to the REP socket's input. This,

again, is run in the background. Finally, connect a REQ socket to that REP

socket and send the string `hello` through it: you should just see the string

`HELLO` printed on stdout.



## (Un)license



This is free and unencumbered software released into the public domain.



Anyone is free to copy, modify, publish, use, compile, sell, or distribute this

software, either in source code form or as a compiled binary, for any purpose,

commercial or non-commercial, and by any means.



In jurisdictions that recognize copyright laws, the author or authors of this

software dedicate any and all copyright interest in the software to the public

domain. We make this dedication for the benefit of the public at large and to

the detriment of our heirs and successors. We intend this dedication to be an

overt act of relinquishment in perpetuity of all present and future rights to

this software under copyright law.



THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE

AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN

ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION

WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.



For more information, please refer to