Filename extension

ts10

Is there a way to test a filename to get the extension? Such as see if a file is a PDF file?

Thanks!

jordy

Im not quite sure what you mean.. just to test the extention is not quite hard:

<?
print_r(pathinfo("/www/htdocs/index.html"))
?>

To really test the file if the extention is correct is a bit harder.. its possible with ceveral libs.. like getimagesize for images:

<?
print_r(getimagesize("myimage.ext"))
?>

You can use libpdf to test if its a pdf file etc. etc. etc.

TheDefender

If all you want to know is if it has a PDF extension, you could use basename() and pull just the last three characters to compare with.

$file = "path/to/file/name.pdf";
$confirm = (substr(basename($file), -3) == "pdf") ? "Yep, the extension is a PDF all right!" : "Nope, doesn't have PDF extension";
echo $confirm;

You could do it without the basename() function and just use the substr, but I personally like to narrow it down to just the file's name before I manipulate it with substr... It's a personal preference thing.

jordy

basename() sometimes has some trouble with files with more than one dot in it.. like: this.is.my.file.ext

I usually use:

function get_extension($filename){
$x=explode(".",strrev($filename));
return strrev($x[0]);
}

TheDefender

I personally haven't had any issues with basename(), but I know what you are referring to... You aren't the first to bring that up. The point of the bottom of my post is that you can use substr() to pull just the extension anyhow... If all you are trying to find is "pdf", then you only need to offset -3 anyhow. It's probably better to just put it into an array anyhow, because you can search the array for any value that equals pdf.

A file called something.pdf.txt could give a positive to show the file could be a pdf renamed with a .txt extension... I guess it depends on how ts10's trying to implement the script.