php include with ".." before file path

Question

I recently was watching a php video tutorial and the author was showing how to do include a file. He was using XAMPP for the demonstrations and had many files.

When he was showing how to include a file, he mentioned something about putting two dots (..) in front of the file path (/xampp/content/example.html) because of something having to do with where the files were located, assuming that I already had knowledge of this principle. But i don't.

Can anyone explain what is up with having one dot or two dots in front of file paths?

What is the difference between include("/xampp/content/example.html");, include("./xampp/content/example.html");, and include("../xampp/content/example.html");

Answer 1

In Linux / Unix environment,

/xampp/content/example.html means absolute path

./xampp/content/example.html means relative path of current directory

../xampp/content/example.html means relative path of parent directory

For the folder structure: /var/www/xampp/content/example3.html:

If your current folder is /var/www/...

• ../ (goes up 1 level) will be /var/
• ./ (in current level) will be /var/www/
• / will be / (in Linux, / means the root of the server, the outermost structure of the filesystem)
• ../../ (goes up 2 level) will be /

There are 2 types of paths: Relative Path & Absolute Path.

For Relative path, it's relative to your current directory. For absolute path, it's not related to your current directory.