Php/docs/stream.streamwrapper.example-1
Example class registered as stream wrapper
The example below implements a var:// protocol handler that allows read/write access to a named global variable using standard filesystem stream functions such as fread(). The var:// protocol implemented below, given the URL "var://foo" will read/write data to/from $GLOBALS["foo"].
Example #1 A Stream for reading/writing global variables
<?phpclass VariableStream { var $position; var $varname; function stream_open($path, $mode, $options, &$opened_path) { $url = parse_url($path); $this->varname = $url["host"]; $this->position = 0; return true; } function stream_read($count) { $ret = substr($GLOBALS[$this->varname], $this->position, $count); $this->position += strlen($ret); return $ret; } function stream_write($data) { $left = substr($GLOBALS[$this->varname], 0, $this->position); $right = substr($GLOBALS[$this->varname], $this->position + strlen($data)); $GLOBALS[$this->varname] = $left . $data . $right; $this->position += strlen($data); return strlen($data); } function stream_tell() { return $this->position; } function stream_eof() { return $this->position >= strlen($GLOBALS[$this->varname]); } function stream_seek($offset, $whence) { switch ($whence) { case SEEK_SET: if ($offset < strlen($GLOBALS[$this->varname]) && $offset >= 0) { $this->position = $offset; return true; } else { return false; } break; case SEEK_CUR: if ($offset >= 0) { $this->position += $offset; return true; } else { return false; } break; case SEEK_END: if (strlen($GLOBALS[$this->varname]) + $offset >= 0) { $this->position = strlen($GLOBALS[$this->varname]) + $offset; return true; } else { return false; } break; default: return false; } } function stream_metadata($path, $option, $var) { if($option == STREAM_META_TOUCH) { $url = parse_url($path); $varname = $url["host"]; if(!isset($GLOBALS[$varname])) { $GLOBALS[$varname] = ; } return true; } return false; }}stream_wrapper_register("var", "VariableStream") or die("Failed to register protocol");$myvar = "";$fp = fopen("var://myvar", "r+");fwrite($fp, "line1\n");fwrite($fp, "line2\n");fwrite($fp, "line3\n");rewind($fp);while (!feof($fp)) { echo fgets($fp);}fclose($fp);var_dump($myvar);?>
The above example will output:
line1 line2 line3 string(18) "line1 line2 line3 "
