user415: Is there a standard, or at least well-accepted, CLI tool that calculates the public key out of a private key?
I've done my homework erading How do you get a Bitcoin Public Key from a Private Key, but it's from May 2014, and hopefully tooling has improved since then.

user35577: To the best of my knowledge there is no standard CLI utility.
However, there are some tools which seem to be generally accepted, like bitcoin-bash-tools
Alternatively, you can use some script library, such as pycoin (written in Python), or bitcoinjs.
Personally I like Bitcore libraries (Bitcore is not Bitcoin Core, despite their names are similar). They are also written in Javascript.
I wrote a simple library for handling keys/addresses that can be used from the command line with the NodeJS interpreter: https://github.com/frz-dev/btcutils/blob/master/bitcore-keys-utils.js. In your case you can use the getPubKey function, passing the private key object.
Hope this helps

user26481: In fact, there are few CLI utilies that allow you this:

sx : command line Bitcoin to empower the sysadmin 
cat key| sx pubkey
pybitcointools : SImple, common-sense Bitcoin-themed Python ECC library 
pybtctool privtopub key


415: <p>Is there a standard, or at least well-accepted, CLI tool that calculates the public key out of a private key?</p>

<p>I've done my homework erading <a href="https://bitcoin.stackexchange.com/questions/25024/how-do-you-get-a-bitcoin-public-key-from-a-private-key">How do you get a Bitcoin Public Key from a Private Key</a>, but it's from May 2014, and hopefully tooling has improved since then.</p>
 35577: <p>To the best of my knowledge there is no standard CLI utility.
However, there are some tools which seem to be generally accepted, like <a href="https://github.com/grondilu/bitcoin-bash-tools" rel="nofollow noreferrer" title="bitcoin-bash-tools">bitcoin-bash-tools</a></p>

<p>Alternatively, you can use some script library, such as <a href="https://github.com/pycoin/pycoin" rel="nofollow noreferrer" title="pycoin">pycoin</a> (written in Python), or <a href="https://github.com/bitcoinjs/bitcoinjs-lib%20%22bitcoinjs%22%20(written%20in%20Javascript)" rel="nofollow noreferrer">bitcoinjs</a>.</p>

<p>Personally I like <a href="https://bitcore.io/api/lib/" rel="nofollow noreferrer">Bitcore</a> libraries (Bitcore is not Bitcoin Core, despite their names are similar). They are also written in Javascript.
I wrote a simple library for handling keys/addresses that can be used from the command line with the NodeJS interpreter: <a href="https://github.com/frz-dev/btcutils/blob/master/bitcore-keys-utils.js" rel="nofollow noreferrer">https://github.com/frz-dev/btcutils/blob/master/bitcore-keys-utils.js</a>. In your case you can use the <code>getPubKey</code> function, passing the private key object.</p>

<p>Hope this helps</p>
 26481: <p>In fact, there are few CLI utilies that allow you this:</p>

<ul>
<li><p><a href="https://github.com/Bobalot/sx" rel="nofollow noreferrer">sx</a> : command line Bitcoin to empower the sysadmin </p>

<p>cat <em>key</em>| sx pubkey</p></li>
<li><p><a href="https://github.com/vbuterin/pybitcointools" rel="nofollow noreferrer">pybitcointools</a> : SImple, common-sense Bitcoin-themed Python ECC library </p>

<p>pybtctool privtopub <em>key</em></p></li>
</ul>
