How to quickly know whether a file exist or not? in PhP

teguh123

What command? File?

paulnaj

file_exists()

teguh123

Now, say I have domain name

http://domain.com

The domain correspond to ~username/public_html/

Can I know what PhP function that will allow me to know the home directory of my domain?

paulnaj

Hi,

Have a good read through the comments at the bottom of the manual page I sent you earlier. There are plenty of ideas there and one might be exactly what you want.

inotgood

there is actually no need for this ~username/public_html/

for example if your index.php is in public_html just use the following below

if(file_exist("./image.jpg")) echo "exist"; else echo "not there";

if you are targeting a file in a subdirectory then just navigate to it like the below

if(file_exist("./images/image.jpg")) echo "exist"; else echo "not there";

NogDog

The home directory of your domain is available via the $_SERVER['DOCUMENT_ROOT'] variable.

bpat1434

And even better if you're using php 5.0 you can use it with urls to see if a file exists at a URL (note, only if fopen wrappers are enabled in php.ini)

teguh123

Okay good.

Thanks.

Now say someone access http://domain.com/file.php?parameters

$_SERVER['REQUEST_URI'] will contain /file.php?parameters right?

However I should check whether /file.php exist or not

How do I get the file part of user request without the parameter? Regular expression of $_SERVER['REQUEST_URI'] or is there faster way?

bpat1434

Umm... if they're trying to access file.php, then file.php will always have to be there because that's what the server will try to find. If it's not found, the server will give you a 404 (Not Found).

inotgood

EASY

dont use $_SERVER['REQUEST_URI']

use $_REQUEST[file] //whatever the parameter is that should be in the []

for example the link is http://domain.com/file.php?file=./image.jpg

if(file_exist($_REQUEST[file])) echo "exist"; else echo "not there";

or if checking files in subdirectory just add the directories to the file parameter
and the php file exist checking code is still the same.

for example the link is http://domain.com/file.php?file=./images/image.jpg

if(file_exist($_REQUEST[file])) echo "exist"; else echo "not there";

bradgrafelman

I guess I might as well continue the pattern...

Don't use $REQUEST. Instead, use $GET (as in this situation) or the corresponding superglobal array according to where you're expecting the data to come from (more info here: [man]variables.predefined[/man]).

In addition, you should check if the index exists first, e.g. don't do:

$file = $_GET['file'];

Rather, you should do:

$file = (isset($_GET['file']) ? $_GET['file'] : '');