title: find all numbers next to a certain keyword
body: <p>I have a text file. It contains some texts. the text is mixed of strings and numbers. I'd like to find all numbers that occur next to a keyword.
  For example (keyword here is <code>day</code>):   </p>
  
  <blockquote>
    <p>Today is really nice <strong>32</strong> day. Tomorrow I will eat 3 pizzas with 10 of my friends next time we will take <strong>50</strong> day or <strong>19</strong> day</p>
  </blockquote>
  
  <p>(sentence is pure nonsense for anyone wondering).
  I'd like to extract numbers <strong>32</strong>, <strong>50</strong> and <strong>19</strong>.  </p>
  
  <p>Im a newbie in bash so far I can read the content from the file and extract all numbers</p>
  
  <pre><code>echo $(grep -Eo '[0-9\]+' $i)
  </code></pre>
  
  <p>edit2:
  keyword MUST be day. daylight, daynight are not allowed. sorry for misunderstading</p>