One dot or two, when moving up directory tree?

bunner_bob

I've always used "../directory" to move up levels in the directory tree, but recently I've seen some paths that use just a single period - "./directory" (I noticed these in the phpMyAdmin config.inc.php file).

What's the difference? Is there a reason to use one or the other?

(I mean hey, I could save typing a couple hundred periods a year! Time to send my fingers on a vacation.)

NogDog

"." == current directory
".." == one level up

bunner_bob

Interesting - why use the dot-slash at all? I've always used "includes/file.php" (vs. ./includes/file.php) and haven't had any trouble...yet.

Should I be adding that "./"?

TheDefender

Either way works fine bunner bob...
I think it's just a bit more definitive in understanding the code when you use the "./" addition... (I tend to use Absolute instead of Relative paths personally. I use the $_SERVER globals to define my path, so it doesn't mater whether it's on my test server, or production servers...)

bunner_bob

I've read about doing absolute paths but I was concerned about moving from test to production servers.

Can tell me your process in a nutshell, or suggest a link about it?

TheDefender

Well, I assume you are using an included config file of some sort, so typically, what I do is something like this in it:

if($_SERVER['HTTP_HOST'] == "localhost") {
$root_path = "http://localhost/";
$db_host = "localhost";
$db_user = "********";
$db_password = "********";
$database = "my_local_db";

} else {
$root_path = "http://www.mydomain.com/";
$db_host = "localhost";
$db_user = "********";
$db_password = "********";
$database = "my_production_db";

}

Then, anytime I need to define a path, I use that $root_path variable. This way, I am always using absolute paths, and it doesn't matter if it's on my local machine, or production server. You can get more detailed, so you can use more than one production server, but this gives you an idea...

echo "<a href=\"".$root_path."/this_file.php\">Link</a>";

Weedpacket

On a note; the reason for the existence of "." is so that the "current directory" can be referred to using a relative path in an unambiguous manner. It makes path algebra much simpler - the way having 0 makes integer arithmetic easier.