user4725: I have a version of bitcoind on my server and I can't remember which version it is.
How can I find out what version my bitcoind is ?
eg: ./bitcoind -version ..or such

user30934: curl code for achieve that (using JSON-RPC)
curl --user YOUR_USER --data-binary '{"jsonrpc": "1.0", "id":"curltest", "method": "getinfo", "params": [] }' -H 'content-type: text/plain;' http://127.0.0.1:8332/

Then it will prompt
Enter host password for user 'YOUR_USER':

Finally just hit your password and get the bitcoin server response
{"result":{"version":666,"protocolversion":666,"walletversion":666,"balance":0.00000000,"blocks":366666,"timeoffset":-9,"connections":8,"proxy":"","difficulty":72722780642.54718018,"testnet":false,"keypoololdest":1448366656,"keypoolsize":666,"paytxfee":0.00000000,"relayfee":0.00001000,"errors":"Warning: Message"},"error":null,"id":"curltest"}

You will see something like after running the command-line above where version is what you want to see
NOTE:
I'm http://127.0.0.1:8332 that means you have to 
ssh your_bitcoin_server

And also you must have your ~/.bitcoin/bitcoin.conf or /etc/bitcoin/bitcoin.conf (as a service) configuration file set to default port (8332)
Feel free to change this as required

user7412: Like GetInfo, the GetNetworkInfo RPC call provides:

version: The numeric Bitcoin Core (bitcoind) server software version (e.g. 100000)
protocolversion: The numeric Bitcoin protocol version of the software (e.g. 70002)

In addition, GetNetworkInfo provides the "subversion" user agent string (e.g "/Satoshi:0.10.0/").
Note that the GetInfo call has been deprecated and may be removed in a future version of the software (source). 

user63569: Please consider using getnetworkinfo info instead of getinfo since bitcoin 0.16.0 
bitcoin-cli getnetworkinfo
{
  "version": 160000,
  "subversion": "/Satoshi:0.16.0/",
  "protocolversion": 70015,
  "localservices": "000000000000040d",
  "localrelay": true,
  "timeoffset": 0,
  "networkactive": true,
  "connections": 5,
  "networks": [
    {
      "name": "ipv4",
      "limited": false,
      "reachable": true,
      "proxy": "",
      "proxy_randomize_credentials": false
    },
    {
      "name": "ipv6",
      "limited": false,
      "reachable": true,
      "proxy": "",
      "proxy_randomize_credentials": false
    },
    {
      "name": "onion",
      "limited": true,
      "reachable": false,
      "proxy": "",
      "proxy_randomize_credentials": false
    }
  ],
  "relayfee": 0.00001000,
  "incrementalfee": 0.00001000,
  "localaddresses": [
  ],
  "warnings": "Warning: unknown new rules activated (versionbit 28)"
}


user323: EDIT: As of 0.16.0, use getnetworkinfo to get the version of bitcoind:

getnetworkinfo: version, protocolversion, timeoffset, connections, proxy, relayfee, warnings

Send a getinfo command to the server. It shows the version of bitcoind:
{
  "version": 80400,
  "protocolversion": 70001,
  "walletversion": 60000,
  "balance": 102.2899977,
  "blocks": 104358,
  "timeoffset": 1,
  "connections": 15,
  "proxy": "",
  "difficulty": 1.0,
  "testnet": true,
  "keypoololdest": 1372886245,
  "keypoolsize": 101,
  "paytxfee": 0.0,
  "errors": ""
}


4725: <p>I have a version of bitcoind on my server and I can't remember which version it is.</p>

<p>How can I find out what version my bitcoind is ?</p>

<p>eg: <code>./bitcoind -version</code> ..or such</p>
 30934: <p>curl code for achieve that (using <a href="http://jsonrpcphp.org/" rel="nofollow">JSON-RPC</a>)</p>

<pre><code>curl --user YOUR_USER --data-binary '{"jsonrpc": "1.0", "id":"curltest", "method": "getinfo", "params": [] }' -H 'content-type: text/plain;' http://127.0.0.1:8332/
</code></pre>

<p>Then it will prompt</p>

<pre><code>Enter host password for user 'YOUR_USER':
</code></pre>

<p>Finally just hit your password and get the bitcoin server response</p>

<pre><code>{"result":{"version":666,"protocolversion":666,"walletversion":666,"balance":0.00000000,"blocks":366666,"timeoffset":-9,"connections":8,"proxy":"","difficulty":72722780642.54718018,"testnet":false,"keypoololdest":1448366656,"keypoolsize":666,"paytxfee":0.00000000,"relayfee":0.00001000,"errors":"Warning: Message"},"error":null,"id":"curltest"}
</code></pre>

<p>You will see something like after running the command-line above where version is what you want to see</p>

<p><strong>NOTE:</strong></p>

<p>I'm <a href="http://127.0.0.1:8332" rel="nofollow">http://127.0.0.1:8332</a> that means you have to </p>

<pre><code>ssh your_bitcoin_server
</code></pre>

<p>And also you must have your ~/.bitcoin/bitcoin.conf or /etc/bitcoin/bitcoin.conf (as a service) configuration file set to default port (8332)</p>

<p>Feel free to change this as required</p>
 7412: <p>Like GetInfo, the <a href="https://bitcoin.org/en/developer-reference#getnetworkinfo" rel="nofollow">GetNetworkInfo</a> RPC call provides:</p>

<ul>
<li>version: The numeric Bitcoin Core (bitcoind) server software version (e.g. 100000)</li>
<li>protocolversion: The numeric Bitcoin protocol version of the software (e.g. 70002)</li>
</ul>

<p>In addition, GetNetworkInfo provides the "subversion" user agent string (e.g "/Satoshi:0.10.0/").</p>

<p>Note that the GetInfo call has been deprecated and may be removed in a future version of the software (<a href="https://bitcoin.org/en/developer-reference#getinfo" rel="nofollow">source</a>). </p>
 63569: <p>Please consider using <code>getnetworkinfo</code> info instead of getinfo since bitcoin 0.16.0 </p>

<p><strong><code>bitcoin-cli getnetworkinfo</code></strong></p>

<pre><code>{
  "version": 160000,
  "subversion": "/Satoshi:0.16.0/",
  "protocolversion": 70015,
  "localservices": "000000000000040d",
  "localrelay": true,
  "timeoffset": 0,
  "networkactive": true,
  "connections": 5,
  "networks": [
    {
      "name": "ipv4",
      "limited": false,
      "reachable": true,
      "proxy": "",
      "proxy_randomize_credentials": false
    },
    {
      "name": "ipv6",
      "limited": false,
      "reachable": true,
      "proxy": "",
      "proxy_randomize_credentials": false
    },
    {
      "name": "onion",
      "limited": true,
      "reachable": false,
      "proxy": "",
      "proxy_randomize_credentials": false
    }
  ],
  "relayfee": 0.00001000,
  "incrementalfee": 0.00001000,
  "localaddresses": [
  ],
  "warnings": "Warning: unknown new rules activated (versionbit 28)"
}
</code></pre>
 323: <p>EDIT: As of 0.16.0, use <code>getnetworkinfo</code> to get the version of bitcoind:</p>

<ul>
<li>getnetworkinfo: version, protocolversion, timeoffset, connections, proxy, relayfee, warnings</li>
</ul>

<p>Send a <code>getinfo</code> <a href="https://en.bitcoin.it/wiki/Original_Bitcoin_client/API_calls_list" rel="noreferrer">command</a> to the server. It shows the version of bitcoind:</p>

<pre><code>{
  "version": 80400,
  "protocolversion": 70001,
  "walletversion": 60000,
  "balance": 102.2899977,
  "blocks": 104358,
  "timeoffset": 1,
  "connections": 15,
  "proxy": "",
  "difficulty": 1.0,
  "testnet": true,
  "keypoololdest": 1372886245,
  "keypoolsize": 101,
  "paytxfee": 0.0,
  "errors": ""
}
</code></pre>
