PHP to determine the file type of upload file types of multiple instance code

PHP Tutorial To determine the file type of upload file multiple instance code

$array = array (' jpg ', ' gif ', ' PNG ', ' jpeg ');

$PICIMG = '/upfile/upload_pic/thumbnail_1258615556.jpg ';

$img = Strtolower ($PICIMG);

Get file name extension method one

$ext = substr ($img, Strrpos ($img, '. ') +1)//Here is the code to read the file name extension

Get file name extension method two

$ext = End (Explode ('. ', $img));

Get file name extension method Three this is supposed to be the safest, is to use PHP $_files[' type '

$ext = $_files[' file ' [' type '];

Get file name extension method four

$ext = getimagesize ($img);//This function returns an array

if (!in_array ($ext, $array))
{
Exit (' Thumbnail address error, please upload again! ');
}
Else
{
Echo (' Your uploaded file type is not allowed ');
Exit;
}

/*
  function Resolution:
  Array Array This does not say
  strtolower characters to lowercase
  substr character interception, the Chinese processing is not friendly.
  Strrpos The position where the character appears in the specified string
  explode split function, return result array
  End read Data last value
  $_files global variable file upload
  getimagesize  Get the type of picture
  In_array Determines if the variable is in an array
  exit terminates the current script run
 
*/
&NBSP