problems retrieving file extension in CI - codeigniter

Question

How can I retrieve the file extension of an image while uploading?
I don't have any problems with the upload, just retrieving the files extension , which would be useful when creating thumbnails dynamically.
Thanks

Answer 1

http://codeigniter.com/user_guide/libraries/file_uploading.html
$this->upload->data()
This is a helper function that returns an array containing all of the data related to the file you uploaded. Here is the array prototype:
Array
(
[file_name] => mypic.jpg
[file_type] => image/jpeg
[file_path] => /path/to/your/upload/
[full_path] => /path/to/your/upload/jpg.jpg
[raw_name] => mypic
[orig_name] => mypic.jpg
[client_name] => mypic.jpg
[file_ext] => .jpg
[file_size] => 22.2
[is_image] => 1
[image_width] => 800
[image_height] => 600
[image_type] => jpeg
[image_size_str] => width="800" height="200"
)
So after the user has uploaded something, you probably want to store the file extension in your database along with other details about the image :-)

Answer 2

$name_of_file_with_extn = $this->upload->data('file_name')
you can change the item name from the below list
file_name Name of the file that was uploaded, including the filename extension
file_type File MIME type identifier
file_path Absolute server path to the file
full_path Absolute server path, including the file name
raw_name File name, without the extension
orig_name Original file name. This is only useful if you use the encrypted name option.
client_name File name as supplied by the client user agent, prior to any file name preparation or incrementing
file_ext Filename extension, period included
file_size File size in kilobytes
is_image Whether the file is an image or not. 1 = image. 0 = not.
image_width Image width
image_height Image height
image_type Image type (usually the file name extension without the period)
image_size_str A string containing the width and height (useful to put into an image tag)
This might help you.

Answer 3

After you uploaded the file, you can get its property by:
$saved_file_name = $this->upload->data('file_name');
// will give you the filename along with the extension
If you want to get only the file extension before uploading it, use core PHP:
$file_ext = pathinfo($_FILES["file"]["name"], PATHINFO_EXTENSION);
or to make it clean
$filename= $_FILES["file"]["name"];
$file_ext = pathinfo($filename,PATHINFO_EXTENSION);