The is_uploaded_file() function in PHP is an inbuilt function which is used to check whether the specified file uploaded via HTTP POST or not. The name of the file is sent as a parameter to the is_uploaded_file() function and it returns True if the file is uploaded via HTTP POST. This function can be used to ensure that a malicious user hasn’t tried to trick the script into working on files upon which it should not be working.
Syntax:
bool is_uploaded_file($file)
Parameters Used: This function accepts single parameter $file.
- $file: It is a mandatory parameter which specifies the file.
Return Value: It returns True if the $file uploaded via HTTP POST. It returns true on success or false in failure. For proper working, the function is_uploaded_file() needs an argument like $_FILES[‘userfile’][‘tmp_name’], – the name of the uploaded file on the clients machine $_FILES[‘userfile’][‘name’] does not work.
Exceptions
- An E_WARNING is emitted on failure.
- The result of this function are cached and therefore the clearstatcache() function is used to clear the cache.
- is_uploaded_file() function returns false for non-existent files.
Below programs illustrate the is_uploaded_file() function.
Program 1:
<?php // PHP program to illustrate is_uploaded_file() function. $myfile = "gfg.txt";   // checking whether the file is uploaded via HTTP POST if (is_uploaded_file($file))     echo ("$file is uploaded via HTTP POST"); else    echo ("$file is not uploaded via HTTP POST"); ?> |
Output:
gfg.txt is not uploaded via HTTP POST
Program 2:
<?php   // checking whether the file is uploaded via HTTP POST if (is_uploaded_file($_FILES['userfile']['gfg.txt'])) {     echo "File ". $_FILES['userfile']['gfg.txt'] .                       " uploaded successfully.\n";                             // displaying contents of the uploaded file     echo "Contents of the file are :\n";     readfile($_FILES['userfile']['gfg.txt']); } else{     echo "File ". $_FILES['userfile']['gfg.txt'] .                   " not uploaded successfully.\n"; } ?> |
Output:
File gfg.txt uploaded successfully. Contents of the file are : Portal for neveropen!
Reference:
http://php.net/manual/en/function.is-uploaded-file.php
