PHP | unlink() Function

The unlink() function is an inbuilt function in PHP which is used to delete files. It is similar to UNIX unlink() function. The $filename is sent as a parameter that needs to be deleted and the function returns True on success and false on failure.

Syntax:

unlink( $filename, $context )

Parameters: This function accepts two parameters as mentioned above and described below: 

• $filename: It is a mandatory parameter which specifies the filename of the file which has to be deleted.
• $context: It is an optional parameter which specifies the context of the file handle which can be used to modify the nature of the stream.

Return Value: It returns True on success and False on failure.

Errors And Exception:

• The unlink() function generates an E_WARNING level error on failure.
• The web server user must have write permissions to the directory for using the unlink() function.
• The unlink() function returns Boolean False but many times it happens that it returns a non-Boolean value which evaluates to False.

Below programs illustrate the unlink() function in PHP:

Suppose there is a file named as “gfg.txt”
Program 1:

PHP

<?php
// PHP program to delete a file named gfg.txt
// using unlink() function

$file_pointer = "gfg.txt";

// Use unlink() function to delete a file
if (!unlink($file_pointer)) {
    echo ("$file_pointer cannot be deleted due to an error");
}
else {
    echo ("$file_pointer has been deleted");
}

?>

Output: 

gfg.txt has been deleted

Program 2:

PHP

<?php
// PHP program to delete a file named gfg.txt
// using unlink() function

$file_pointer = fopen('gfg.txt', 'w+');

// writing on a file named gfg.txt
fwrite($file_pointer, 'A computer science portal for geeks!');
fclose($file_pointer);

// Use unlink() function to delete a file
if (!unlink($file_pointer)) {
    echo ("$file_pointer cannot be deleted due to an error");
}
else {
    echo ("$file_pointer has been deleted");
}

?>

Output: 

Warning: unlink() expects parameter 1 to be a valid path, resource
given in C:\xampp\htdocs\server.php on line 12
Resource id #3 cannot be deleted due to an error

Reference: http://php.net/manual/en/function.unlink.php