How to add line numbers to all lines in Google Prettify?

Solution

Instead of modifying the CSS you can simply add in a line of CSS to achieve the desired behavior:

<style>

    .prettyprint ol.linenums > li { list-style-type: decimal; }

</style>  

Example

A full example might have the code below. View results via jsfiddle or see below

<link rel="stylesheet" href="//cdnjs.cloudflare.com/ajax/libs/prettify/r298/prettify.min.css" />

    <style>
        .prettyprint ol.linenums > li { list-style-type: decimal; }
    </style>

<pre class="prettyprint linenums">
 foo
 bar
 bis
 sed
 awk
 cat
</pre>


<script src="//cdnjs.cloudflare.com/ajax/libs/prettify/r298/prettify.min.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/prettify/r298/run_prettify.js"></script>

The root cause is list-style-type: none in prettify.css:

/* Specify class=linenums on a pre to get line numbering */
ol.linenums { margin-top: 0; margin-bottom: 0 } /* IE indents via margin-left */
li.L0,
li.L1,
li.L2,
li.L3,
li.L5,
li.L6,
li.L7,
li.L8 { list-style-type: none /* <<< THIS is the cause! */ }
/* Alternate shading for lines */
li.L1,
li.L3,
li.L5,
li.L7,
li.L9 { background: #eee }

You can either remove that rule or override it with:

.linenums li {
    list-style-type: decimal;
}

I like having the alternating background colors, so did it this way:

/* White background color for all even-numbered lines */
li.L0,
li.L2,
li.L4,
li.L6,
li.L8  { background-color: #fff; }
/* Light-gray background color for all odd-numbered lines */
li.L1,
li.L3,
li.L5,
li.L7,
li.L9 { background-color: #eee; }