title: grep json keys from output stream
body: <p>For instance I have a JSON file like this:</p>
  
  <pre><code>{
      "mac": "00:11:22:33:44:55",
      "name: "Test123",
      "ssid": "29321",
      "password": "txt",
      "data": {
          "test:": "no",
          "dev": "yes",
          "prod": false
      },
      "signals": [12, 34, 65, 93, 21],
  }
  </code></pre>
  
  <p>I'd like to grep a particular JSON key (including subkeys) from data above, but when I <code>cat</code> that file or read a JSON file from somewhere else in the output stream, ie <code>wget</code> or <code>curl</code>.</p>
  
  <p>So far I have tried only this:</p>
  
  <pre><code>cat json.txt | grep -o -E '([[:xdigit:]]{1,2}:){5}[[:xdigit:]]{1,2}'
  </code></pre>
  
  <p>This returns the <code>"mac"</code> key value, grep's it by a pattern, strips all the quotes in the output and it really works flawlessly!</p>
  
  <p>I honestly haven't tried anything regardings JSON keys, since any regular-expression system is not my stronger point and I hope you'll all help me about this.</p>
  
  <p><strong>NOTE:</strong> I'm very limited on the system where I'll be running this, so the <code>-P</code> option is not available.</p>
  
  <hr>
  
  <p><strong>EDIT:</strong> Actually, we do have root access to devices. They're running on <a href="https://www.imgtec.com/mips/" rel="nofollow noreferrer">MIPS platform</a> and we have no compilers on the system installed. All the apps we can install must be already precompiled, so I doubt I'll find <code>jq</code> or <code>jshon</code> for these devices.</p>
  
  <p>If there's another tool, that'd be helpful, probably.</p>
  
  <hr>
  
  <p><strong>EDIT 2:</strong> Issuing command: <code>akw --version</code>, we get this response:</p>
  
  <pre><code>BusyBox v1.19.‎4 (2017-03-27 19:07:06 EEST) multi-call binary.
  </code></pre>