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Last active September 23, 2025 07:02
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  1. kfox revised this gist Mar 14, 2023. No changes.
  2. kfox revised this gist Mar 14, 2023. 1 changed file with 7 additions and 0 deletions.
    7 changes: 7 additions & 0 deletions README.md
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    # TCP echo server for Node.js

    ## Usage

    1. Make sure you have a modern-ish version of Node.js installed.
    2. Type `npx https://gist.github.com/kfox/1280c2f0ee8324067dba15300e0f2fd3`
    3. Connect to it from a client, e.g. `netcat` or similar: `nc localhost 9000`
  3. kfox revised this gist Mar 14, 2023. 1 changed file with 5 additions and 0 deletions.
    5 changes: 5 additions & 0 deletions package.json
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    {
    "name": "tcp-echo-server",
    "version": "1.0.0",
    "bin": "./echo.mjs"
    }
  4. kfox revised this gist Mar 14, 2023. 1 changed file with 2 additions and 0 deletions.
    2 changes: 2 additions & 0 deletions echo.mjs
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    #!/usr/bin/env node

    import net from 'node:net'

    const port = process.argv[2] || 9000
  5. kfox created this gist Mar 14, 2023.
    24 changes: 24 additions & 0 deletions echo.mjs
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    import net from 'node:net'

    const port = process.argv[2] || 9000

    const server = net.createServer((connection) => {
    const { address, port } = connection.address()
    const socket = `${address}:${port}`

    console.log(`${socket} - client connected`)

    connection.on('data', (data) => {
    console.log(`${socket} - client sent: %s`, String(data).trim())
    connection.write(data)
    })

    connection.on('end', () => {
    console.log(`${socket} - client disconnected`)
    })
    })

    server.listen({ port }, () => {
    const { address, port } = server.address()
    console.log('listening on %s:%d', address, port)
    })