title: What special meaning does an equal-sign have in zsh?
body: <p>In my zsh script, I had a line</p>
  
  <pre><code>echo some text ================================
  </code></pre>
  
  <p>To my surprise, an error message was issued for this line:</p>
  
  <pre><code>zsh: =============================== not found
  </code></pre>
  
  <p>Experimenting from the command line, I found that the shell gets upset when there is an equal sign:</p>
  
  <pre><code>$ echo =z
  zsh: z not found
  </code></pre>
  
  <p>But here, we have:</p>
  
  <pre><code>$ echo =echo
  /usr/bin/echo
  </code></pre>
  
  <p>From this observation, it looks, as if </p>
  
  <pre><code>=XXX
  </code></pre>
  
  <p>would be interpreted like</p>
  
  <pre><code>$(which XXX)
  </code></pre>
  
  <p>However, I didn't find anything about this "substitution" in the zsh manpage. Where is this piece of magic described?</p>