Question

Here is the include file called ‘VariablesFunctions.php’:

$currWebPage = '';
function getPageUrl( )
{
    global $currWebPage; 
    if( $_SERVER['HTTPS'] == 'on' ) $currWebPage .= 's';
    $currWebPage .= '://';
    if( $_SERVER["SERVER_PORT"] != "80" )
        $currWebPage .= $_SERVER["SERVER_NAME"].":".$_SERVER["SERVER_PORT"].$_SERVER["REQUEST_URI"];
    else $currWebPage .= $_SERVER["SERVER_NAME"].$_SERVER["REQUEST_URI"];
}  

here is the file (index.php) which calls it:

<?php include( 'VariablesFunctions.php' );
      getPageUrl( );
  echo $currWebPage;
?>

both files are saved in same directory, and when launching the index.php file the browser says undefined function (line 2 above in index.php file), why?

Answer 1

This sometimes means another include file with the same name (old or backup version) exists elsewhere in the include_path. To avoid that, use an explicit path and force it to fail reliably:

<?php require('./VariablesFunctions.php');
    getPageUrl();

The issue might also be caused by your mixed-case filenames. On BSD/Linux servers the filenames must match exactly, they are not considered case-insensitive.

Also: avoid returning results via a global variable, make it a proper return value.