title: printf command inside a script returns "invalid number"
body: <p>I can't get <code>printf</code> to print a variable with the %e descriptor in a bash script. It would just say</p>
  
  <pre><code>#!/bin/bash
  a=14.9
  printf %e 14.9;
  </code></pre>
  
  <p>I know this is likely a very easy question, but I'm fairly new to bash and always used <code>echo</code>. Plus I couldn't find an answer anywhere.</p>
  
  <hr>
  
  <p>when run i get</p>
  
  <pre><code>$ ./test.text
  ./test.text: line 3: printf: 14.9: invalid number
  0,000000
  </code></pre>
  
  <p>therefore my problem is the locale variable LC_NUMERIC: it is set so that i use commas as decimal separators. Indeed, it is set to an european localization:</p>
  
  <pre><code>$ locale | grep NUM
  LC_NUMERIC="it_IT.UTF-8"
  </code></pre>
  
  <p>I thought I set it to en_US.UTF-8, but evidently I didn't. Now the problem switches to find how to set my locale variable. Simply using</p>
  
  <pre><code>$ LC_NUMERIC="en_US.UTF-8"
  </code></pre>
  
  <p>won't work.</p>