PHP is_writable() Function

The PHP is_writable() function checks whether a file exists and is writable.

Note: The results of this function are cached. Use clearstatcache() function to clear the cache.

Syntax

is_writable(filename)

Parameters

filename Required. Specify the path to the file to check.

Return Value

Returns true if the file or directory specified by filename exists and is writable, otherwise returns false.

Note: This function may return true for directories. Use is_dir() to distinguish file and directory.

Exceptions

Upon failure, an E_WARNING is thrown.

Example:

Lets assume that we have a file called test.txt in the current working directory. The example below demonstrates on using this function to check whether a file exists and is writable.

<?php
$file1 = 'test.txt';
$file2 = 'demo.txt';

//checking if $file1 is writable
if(is_writable($file1)) {
  echo "The file $file1 is writable.\n";
} else {
  echo "The file $file1 is not writable.\n";
}

//checking if $file2 is writable
if(is_writable($file2)) {
  echo "The file $file2 is writable.\n";
} else {
  echo "The file $file2 is not writable.\n";
}
?>

The output of the above code will be:

The file test.txt is writable.
The file demo.txt is not writable.

❮ PHP Filesystem Reference