php man page for is_readable

IS_READABLE(3)								 1							    IS_READABLE(3)

is_readable - Tells whether a file exists and is readable

SYNOPSIS
       bool is_readable (string  $filename)

DESCRIPTION
	Tells whether a file exists and is readable.

PARAMETERS
	      o $filename
		- Path to the file.

RETURN VALUES
	Returns TRUE if the file or directory specified by $filename exists and is readable, FALSE otherwise.

EXAMPLES
       Example #1

	      is_readable(3) example

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

ERRORS
/EXCEPTIONS
	Upon failure, an E_WARNING is emitted.

NOTES
	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 before PHP 5.1.5.

       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.

       Note

	       The check is done using the real UID/GID instead of the effective one.

	This function may return TRUE for directories. Use is_dir(3) to distinguish file and directory.

SEE ALSO
       is_writable(3), file_exists(3), fgets(3).

PHP Documentation Group 													    IS_READABLE(3)