php man page for is_writable

IS_WRITABLE(3)								 1							    IS_WRITABLE(3)

is_writable - Tells whether the filename is writable

SYNOPSIS
       bool is_writable (string  $filename)

DESCRIPTION
	Returns  TRUE  if the $filename exists and is writable. The filename argument may be a directory name allowing you to check if a directory
       is writable.

	Keep in mind that PHP may be accessing the file as the user id that the web server runs as (often 'nobody'). Safe mode limitations are not
       taken into account.

PARAMETERS
	      o $filename
		- The filename being checked.

RETURN VALUES
	Returns TRUE if the $filename exists and is writable.

EXAMPLES
       Example #1

	      is_writable(3) example

	      <?php
	      $filename = 'test.txt';
	      if (is_writable($filename)) {
		  echo 'The file is writable';
	      } else {
		  echo 'The file is not writable';
	      }
	      ?>

ERRORS
/EXCEPTIONS
	Upon failure, an E_WARNING is emitted.

NOTES
       Note

	      The results of this function are cached. See clearstatcache(3) for more details.

       Tip

	      As  of  PHP  5.0.0,  this function can also be used with some URL wrappers. Refer to "Supported Protocols and Wrappers" to determine
	      which wrappers support stat(3) family of functionality.

SEE ALSO
       is_readable(3), file_exists(3), fwrite(3).

PHP Documentation Group 													    IS_WRITABLE(3)