PHP | unlink() Function

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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($file_pointer, 'A computer science portal for zambiatek!'); 
fclose($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