Question

I need to update a constant defined in a PHP file. The constants.php file is quite simple:

<?php
$firstConstant = "abcd";
$third = "abcd";

$updatedOn = "23 April 2001";
?>

Now what I need is for my C# application to update the $updatedOn constant in this file to the present date.

How can I accomplish this? Thanks in advance!

Answer 1

You could write a regular expression which matches $updatedOn = "23 April 2001";, generate the replacement line to go in the file and then use the String.Replace method to replace your entire line with the new one you have created. Here’s a regex to get you started:

\$updatedOn = \"([A-Za-z\W0-9]+)\"

For something a bit more flexible, you could write a simple parser which understands a subset of PHP – i.e. code tags and assignments/string constants – parse the file, put the key/value pairs into a dictionary, update the relevant values, and write it back out again.

Some Regular Expression resources:

• 30 minute regex tutorial
• Regex in C#
• An example of using sub groups