URI提供了很多帮你对uri_string分段分割的方法，你可以很轻松的得到uri中某一段。如：
$this->uri->segment(n)
$this->uri->rsegment(n)
$this->uri->slash_segment(n)
$this->uri->slash_rsegment(n)
$this->uri->uri_to_assoc(n)
$this->uri->ruri_to_assoc(n)
config =& load_class('Config', 'core'); log_message('debug', "URI Class Initialized"); } //获取uri_string function _fetch_uri_string() { //$this->config->item('uri_protocol')是获取config.php中uri_protocol的配置，AUTO为默认 if (strtoupper($this->config->item('uri_protocol')) == 'AUTO') { // 命令行方式执行 if (php_sapi_name() == 'cli' or defined('STDIN')) { $this->_set_uri_string($this->_parse_cli_args()); return; } // REQUEST_URI方式，绝大部分情况都能获取 if ($uri = $this->_detect_uri()) { $this->_set_uri_string($uri); return; } // PATH_INFO方式 $path = (isset($_SERVER['PATH_INFO'])) ? $_SERVER['PATH_INFO'] : @getenv('PATH_INFO'); if (trim($path, '/') != '' && $path != "/".SELF) { $this->_set_uri_string($path); return; } // QUERY_STRING方式 $path = (isset($_SERVER['QUERY_STRING'])) ? $_SERVER['QUERY_STRING'] : @getenv('QUERY_STRING'); if (trim($path, '/') != '') { $this->_set_uri_string($path); return; } // 尝试最后一种方式，通过$_GET获取键名 if (is_array($_GET) && count($_GET) == 1 && trim(key($_GET), '/') != '') { $this->_set_uri_string(key($_GET)); return; } // 如果还没获取到uri_string ,只能返回空了 $this->uri_string = ''; return; } //其实下面很多都是把上面的东西重写了，这是根据用户在config.php中配置的 $uri = strtoupper($this->config->item('uri_protocol')); //若为REQUEST_URI方式 if ($uri == 'REQUEST_URI') { $this->_set_uri_string($this->_detect_uri()); return; } elseif ($uri == 'CLI') { $this->_set_uri_string($this->_parse_cli_args()); return; } $path = (isset($_SERVER[$uri])) ? $_SERVER[$uri] : @getenv($uri); $this->_set_uri_string($path); } // -------------------------------------------------------------------- //就是给uri_string赋值 function _set_uri_string($str) { // 防止在ASCII字符之间插入空字符，如Java script. $str = remove_invisible_characters($str, FALSE); // If the URI contains only a slash we'll kill it $this->uri_string = ($str == '/') ? '' : $str; } // -------------------------------------------------------------------- //检测URI private function _detect_uri() { //$_SERVER['REQUEST_URI']和$_SERVER['SCRIPT_NAME']两者都存在才可使用 if ( ! isset($_SERVER['REQUEST_URI']) OR ! isset($_SERVER['SCRIPT_NAME'])) { return ''; } $uri = $_SERVER['REQUEST_URI']; //去掉相同的部分，剩下有用的uri部分 if (strpos($uri, $_SERVER['SCRIPT_NAME']) === 0) { $uri = substr($uri, strlen($_SERVER['SCRIPT_NAME'])); } elseif (strpos($uri, dirname($_SERVER['SCRIPT_NAME'])) === 0) { $uri = substr($uri, strlen(dirname($_SERVER['SCRIPT_NAME']))); } //允许?/welcome/index这种格式 if (strncmp($uri, '?/', 2) === 0) { $uri = substr($uri, 2); } $parts = preg_split('#?#i', $uri, 2); $uri = $parts[0]; if (isset($parts[1])) { $_SERVER['QUERY_STRING'] = $parts[1]; parse_str($_SERVER['QUERY_STRING'], $_GET); } else { $_SERVER['QUERY_STRING'] = ''; $_GET = array(); } if ($uri == '/' || empty($uri)) { return '/'; } $uri = parse_url($uri, PHP_URL_PATH); //做最后的处理返回uri return str_replace(array('//', '../'), '/', trim($uri, '/')); } // -------------------------------------------------------------------- //解析命令行方式参数 private function _parse_cli_args() { $args = array_slice($_SERVER['argv'], 1); return $args ? '/' . implode('/', $args) : ''; } // -------------------------------------------------------------------- //过滤不合法的url字符，允许的uri是你的配置$config['permitted_uri_chars'] = 'a-z 0-9~%.:_-'; function _filter_uri($str) { if ($str != '' && $this->config->item('permitted_uri_chars') != '' && $this->config->item('enable_query_strings') == FALSE) { if ( ! preg_match("|^[".str_replace(array('\-', '-'), '-', preg_quote($this->config->item('permitted_uri_chars'), '-'))."]+$|i", $str)) { show_error('The URI you submitted has disallowed characters.', 400); } } // Convert programatic characters to entities $bad = array('$', '(', ')', '%28', '%29'); $good = array('$', '(', ')', '(', ')'); return str_replace($bad, $good, $str); } // -------------------------------------------------------------------- //如果你配置了url_suffix，则去掉 function _remove_url_suffix() { if ($this->config->item('url_suffix') != "") { $this->uri_string = preg_replace("|".preg_quote($this->config->item('url_suffix'))."$|", "", $this->uri_string); } } // -------------------------------------------------------------------- //用/分隔uri_string,将结果保存到segments中 function _explode_segments() { foreach (explode("/", preg_replace("|/*(.+?)/*$|", "\1", $this->uri_string)) as $val) { // Filter segments for security $val = trim($this->_filter_uri($val)); if ($val != '') { $this->segments[] = $val; } } } //这个是重建索引，将数组从下标1开始，这是为了你的使用习惯，如$this->uri->segment(1)就是获取第一段 function _reindex_segments() { array_unshift($this->segments, NULL); array_unshift($this->rsegments, NULL); unset($this->segments[0]); unset($this->rsegments[0]); } // -------------------------------------------------------------------- //获取uri中的一个片段 function segment($n, $no_result = FALSE) { return ( ! isset($this->segments[$n])) ? $no_result : $this->segments[$n]; } // -------------------------------------------------------------------- //返回确定路由后的一个uri片段 function rsegment($n, $no_result = FALSE) { return ( ! isset($this->rsegments[$n])) ? $no_result : $this->rsegments[$n]; } function uri_to_assoc($n = 3, $default = array()) { return $this->_uri_to_assoc($n, $default, 'segment'); } function ruri_to_assoc($n = 3, $default = array()) { return $this->_uri_to_assoc($n, $default, 'rsegment'); } function _uri_to_assoc($n = 3, $default = array(), $which = 'segment') { if ($which == 'segment') { $total_segments = 'total_segments'; $segment_array = 'segment_array'; } else { $total_segments = 'total_rsegments'; $segment_array = 'rsegment_array'; } if ( ! is_numeric($n)) { return $default; } if (isset($this->keyval[$n])) { return $this->keyval[$n]; } if ($this->$total_segments() < $n) { if (count($default) == 0) { return array(); } $retval = array(); foreach ($default as $val) { $retval[$val] = FALSE; } return $retval; } $segments = array_slice($this->$segment_array(), ($n - 1)); $i = 0; $lastval = ''; $retval = array(); foreach ($segments as $seg) { if ($i % 2) { $retval[$lastval] = $seg; } else { $retval[$seg] = FALSE; $lastval = $seg; } $i++; } if (count($default) > 0) { foreach ($default as $val) { if ( ! array_key_exists($val, $retval)) { $retval[$val] = FALSE; } } } // Cache the array for reuse $this->keyval[$n] = $retval; return $retval; } //很明显，它是将数组中的信息翻转成uri_string function assoc_to_uri($array) { $temp = array(); foreach ((array)$array as $key => $val) { $temp[] = $key; $temp[] = $val; } return implode('/', $temp); } //通过第二个参数看是否给uri前后加上“/”线 function slash_segment($n, $where = 'trailing') { return $this->_slash_segment($n, $where, 'segment'); } function slash_rsegment($n, $where = 'trailing') { return $this->_slash_segment($n, $where, 'rsegment'); } function _slash_segment($n, $where = 'trailing', $which = 'segment') { $leading = '/'; $trailing = '/'; if ($where == 'trailing') { $leading = ''; } elseif ($where == 'leading') { $trailing = ''; } return $leading.$this->$which($n).$trailing; } // -------------------------------------------------------------------- //返回uri片段数组 function segment_array() { return $this->segments; } function rsegment_array() { return $this->rsegments; } //计算uri片段的个数 function total_segments() { return count($this->segments); } function total_rsegments() { return count($this->rsegments); } // -------------------------------------------------------------------- //返回uri_string function uri_string() { return $this->uri_string; } function ruri_string() { return '/'.implode('/', $this->rsegment_array()); }} 