Need an idea for stripping info

jkurrle

Anybody have a quick idea how to strip some info of the back of a variable? One of my server variables is SCRIPT_URI. I would like to strip the filename from the end of this variable and use the remaining directory information to check it against a security database.

I would assume that I could read the variable from right to left and delete everything from the last / on, but the mechanics escape me.

Any help would be greatly appreciated. Thanks

John K

bladx

Check out substr_replace()

http://us3.php.net/substr_replace

planetsim

Why not use basename()

bladx

Hey cool,
that's a useful function,
i was using substr for something like that earlier today, didn't realize there was a more specific function... cool

planetsim

PHP is full of these wonderful functions 😃

bladx

LOL, yeah it is!
thanks again for the pointer

jkurrle

I actually needed a function that does not rely on a specific number to count back from. I need to use this function throughout my directory tree and the file name will be different character lengths throughout.

My goal is to set up a security app, which is tied to a MySQL database, which has permissions for various directories. If a person tries to directly type the URL to a file, the server side includes will have a php script that will determine what directory the person is trying to access, then check it against the security database, to see if they are allowed.

I am looking at something like array_pop(explode('/', $fpath)); but how do I drop the last value of the array, and then reconstitute it? I realize this may seem relatively simple to you gurus, but I'm crash-learning php and haven't gotten too far yet. Unfortunately, I'm expected to produce results yesterday. :-(

Any constructive advice would be greatly appreciated.

Thanks,
John

jordy

okay little example:

string is: 1.2.3.4

$str = "1.2.3.4";

// Example

// make a array of the string splitted by dot
$arr = explode(".",$str);

$lastelement = array_pop($arr);

// loop through the array and
for ($n=0; $n != sizeof($arr); $n++) {
if ($n != 0) // don't start the string with a dot
$strnew .= "."; // place a dot
$strnew .= $arr[$n]; // append the value
}

echo $strnew; // returns 1.2.3
echo $lastelement; // returns 4

jkurrle

That's exactly what I wanted. I just substituted "/" for "." and I'm set.

Thanks.

John K

Weedpacket

Well, if you only needed to find the last /, then [man]strrpos[/man] would have found it for you.

jordy

Weedpacket:

how do I drop the last value of the array, and then reconstitute it?

This is a way to do this.. and yes there is a way to include strpos in the code..

jkurrle

This is the code I ended up adapting and writing...

=====
<?php
function whatdir($directory)
{

// make a array of the string splitted by a slash
$arr = explode("/",$directory);

// take the filename from the end of the array
$lastelement = array_pop($arr);

// loop through the array and
for ($n=0; $n != sizeof($arr); $n++)
{
if ($n != 0) // don't start the string with a slash
$strnew .= "/"; // place a slash
$strnew .= $arr[$n]; // append the value
}

return $strnew; //sends info back to calling program
}

?>

Then I could run the following script:

=====
<?php
$fpath = $_SERVER['SCRIPT_URL'];
echo whatdir($fpath); // returns 1/2/3/...

?>

and it will display the working web directory. If I used SCRIPT_URI instead of SCRIPT_URL I could get a full directory listing, but for my needs SCRIPT_URL works just fine.