CI framework source code reading---------URI.php_PHP tutorial

          if (trim($path, '/') != '')

                                                                 

      }  

// As a last ditch effort lets try using the $_GET array

                      // If neither PATH_INFO nor QUERY_STRING is found, we can only use $_GET

if (is_array($_GET) && count($_GET) == 1 && trim(key($_GET), '/') != '')

                                                                 

      }  

// We've exhausted all our options...

// After the above efforts, we have not found URI, so we really can't find

$this->uri_string = '';

return;

} }

// I have rewritten it here to get uri_protocol. In fact, I think it is completely possible to get it only once. . .

$uri = strtoupper($this->config->item('uri_protocol'));

// The following is to choose different methods to obtain uri according to different methods

if ($uri == 'REQUEST_URI')

{

$this->_set_uri_string($this->_detect_uri());

return;

} }

elseif ($uri == 'CLI')

{

$this->_set_uri_string($this->_parse_cli_args());

return;

} }

// If the uri_protocol you define is outside the three methods of AUTO REQUEST_URI CLI, execute the following paragraph.

$path = (isset($_SERVER[$uri])) ? $_SERVER[$uri] : @getenv($uri);

$this->_set_uri_string($path);

}

//------------------------------------------------ -----------------------

/** 

     * Set the URI String 

     * 

     * @access  public 

     * @param   string 

     * @return  string 

     */

function _set_uri_string($str)

{

// Filter out control characters

// Filter string remove_invisible_characters function is in common.php

$str = remove_invisible_characters($str, FALSE);

// If the URI contains only a slash we'll kill it

// If the string contains only one /, clear it

$this->uri_string = ($str == '/') ? '' : $str;

}

//------------------------------------------------ -----------------------

/**

* Detects the URI

* Search uri

* This function will detect the URI automatically and fix the query string

* if necessary. Necessities

* This function will automatically find the uri and fix the query string if necessary.

*

* @access private

* @return string

*/

private function _detect_uri()

{

// If one of the two values ​​is missing, return (the two variables come from the web server. When encountering some special server programs, this may be empty.)

if ( ! isset($_SERVER['REQUEST_URI']) OR ! isset($_SERVER['SCRIPT_NAME']))

{

            return '';                                      

$uri = substr($uri, strlen($_SERVER['SCRIPT_NAME']));

} }

// The effect here is the same as above, except that $_SERVER['SCRIPT_NAME'] is replaced by

// dirname($_SERVER['SCRIPT_NAME'])

elseif (strpos($uri, dirname($_SERVER['SCRIPT_NAME'])) === 0)

{

$uri = substr($uri, strlen(dirname($_SERVER['SCRIPT_NAME'])));

} }

// This section ensures that even on servers that require the URI

// to be in the query string (Nginx) a correct correct

// URI is found, and also fixes the QUERY_STRING server var and $_GET array.

// This part ensures that the uri can be found correctly even on the Nginx server, and also fixes the QUERY_STRING server and $_GET array.

// Determine whether the first two characters of $uri are the same?/

if (strncmp($uri, '?/', 2) === 0)

{

                                      // Remove the first two characters

} } //Return the path part of this url. $uri = parse_url($uri, PHP_URL_PATH); // Do some final cleaning of the URI and return it // Replace // ../ in uri with / Return return str_replace(array('//', '../'), '/', trim($uri, '/')); } //------------------------------------------------ ----------------------- /** * Parse cli arguments * Parse cli parameters * Take each command line argument and assume it is a URI segment. * If you do this in the command line * php d:/wamp/www/CodeIgniter/index.php welcome index * _parse_cli_args() returns a string of /welcome/index * * @access private * @return string */ private function _parse_cli_args() { // Returns the parameters passed when running in command line mode. // Because the first parameter is the current file name, we want to get it starting from the second one. $args = array_slice($_SERVER['argv'], 1); //Return a string concatenated by '/' strings, because $this->uri_string is a string. return $args ? '/' . implode('/', $args) : ''; } //------------------------------------------------ ----------------------- /** * Filter segments for malicious characters * Filter illegal characters * @access private * @param string * @return string */ function _filter_uri($str) { if ($str != '' && $this->config->item('permitted_uri_chars') != '' && $this->config->item('enable_query_strings') == FALSE ) {                   // preg_quote() in PHP 5.3 escapes -, so the str_replace() and addition of - to preg_quote() is to maintain backwards backwards // compatibility compatibility as many are unaware of how characters in the permitted_uri_chars will be parsed as a regex pattern // It probably means because of PHP5.3.0 characters -increased as a need for righteousness. So when using str_replace() here, you need to add preg_quote() to escape -                                                                                                                                                                          '-'))."]+$|i", $str))                                                                   return array();       }   $retval = array(); foreach ($default as $val)