php man page for posix_access

POSIX_ACCESS(3) 							 1							   POSIX_ACCESS(3)

posix_access - Determine accessibility of a file

SYNOPSIS
       bool posix_access (string  $file, [int  $mode = POSIX_F_OK])

DESCRIPTION
       posix_access(3) checks the user's permission of a file.

PARAMETERS
	      o $file
		- The name of the file to be tested.

	      o $mode
		-  A  mask  consisting of one or more of POSIX_F_OK, POSIX_R_OK, POSIX_W_OK and POSIX_X_OK.  POSIX_R_OK, POSIX_W_OK and POSIX_X_OK
		request checking whether the file exists and has read, write and execute  permissions,	respectively.	POSIX_F_OK  just  requests
		checking for the existence of the file.

RETURN VALUES
	Returns TRUE on success or FALSE on failure.

EXAMPLES
       Example #1

	      posix_access(3) example

	       This example will check if the $file is readable and writable, otherwise will print an error message.

	      <?php

	      $file = 'some_file';

	      if (posix_access($file, POSIX_R_OK | POSIX_W_OK)) {
		  echo 'The file is readable and writable!';

	      } else {
		  $error = posix_get_last_error();

		  echo "Error $error: " . posix_strerror($error);
	      }

	      ?>

NOTES
       Note

	      When  safe  mode is enabled, PHP checks whether the files or directories being operated upon have the same UID (owner) as the script
	      that is being executed.

SEE ALSO
       posix_get_last_error(3), posix_strerror(3).

PHP Documentation Group 													   POSIX_ACCESS(3)