ncast

Dynamic stream multiplexer by broadcasting over a network port.

Setup

$ npm install -g ncast

💡 Alternatively, you can use npx ncast instead of ncast so that you don't even need to install it.

Usage

NAME
    ncast — Dynamic stream multiplexer by broadcasting over a network port.

SYNOPSIS
    ncast [modifiers...]

DESCRIPTION
    Listen to a network port (broadcast mode) and pipes standard input to every
    connected client or connect to that port (client mode) and pipes everything
    to standard output.

    If port is not open or is closed by the (ncast -b) server, clients persist
    and reconnect as soon as server is available again. This way server process
    can be respawned as needed.

    The options are as follows:

    -b, --broadcast
        Broadcast mode. 

    -p <port>, --port <port>  (Default 2549)
        Set network port to listen / connect to.

    -h <host>, --host <host>  (Default localhost)
        Set host name or IP to listen / connect to.

    -s, --silent
        Enable silent mode.

    -v, --version
        Show version and exit.

    -h, --help
        Show this help message and exit.
    
EXAMPLES (Broadcast mode)
    find / 2>&1 | ncast -b > logfile.txt
        Copy standard input (standard output and error of 'find /' command) to
        standard output and then pipe it to 'logfile.txt'. But listens to
        localhost:2549 and every time a new client connects, start copying the
        output to that client too. Unlimited number of clients can connect
        concurrently.

    tail -F example.log | ncast -b --silent
        Like previous example, but monitoring existing log file. It uses
        --silent to prevent sending everything to standard output.

    tail -F example.log | ncast -b --host 0.0.0.0
        Broadcast to all network interfaces.

EXAMPLES (Client mode)
    ncast
        Connect and persist to default host and port (localhost:2549) and copy
        everything received to standard output.

    ncast | grep -i '^error:'
        Like previous example but show only messages beginning with the text
        "error:" (case insensitive).

    ncast | grep -vi '^error:'
        Inverse of the previous case (text not beginning in "error").

    ncast | awk '{ if (tolower($1) == "error:") {sum += 1; print "Errors:", sum }}'
        Using awk to get a real time count.

    ncast --silent
        Does not show anything, but can be useful to monitor server
        connection/disconnection watching reports on standard error.

COPYRIGHT
    MIT License
    Copyright © 2025 Joan Miquel Torres Rigo <[email protected]>

    This is free software: you are free to change and redistribute it.  There
    is NO WARRANTY, to the extent permitted by law.