Mac command line say "bad math expression: operand expected at end of string"
<p>On macbook terminal, when i hit the command TAB key after <code>ls</code>.
Terminal say error.</p>

<pre><code>$ ls
_complete:96: bad math expression: operand expected at end of string
</code></pre>

<p>This example is <code>ls</code>, but other all command has same trouble.
I rebooted mac but trouble has not cleared.</p>

<p>What's happen do you know?</p>

<hr>

<p>Mac was shutdown by himself automatically, and repaired before i knew it.</p>

<p>OS is:  OS X El Capitan.</p>