function usage($error = null, $helpsubject = null)
{
global $progname, $all_commands;
$stderr = fopen('php://stderr', 'w');
if (PEAR::isError($error)) {
fputs($stderr, $error->getMessage() . "\n");
} elseif ($error !== null) {
fputs($stderr, "{$error}\n");
}
if ($helpsubject != null) {
$put = cmdHelp($helpsubject);
} else {
$put = "Commands:\n";
$maxlen = max(array_map("strlen", $all_commands));
$formatstr = "%-{$maxlen}s %s\n";
ksort($all_commands);
foreach ($all_commands as $cmd => $class) {
$put .= sprintf($formatstr, $cmd, PEAR_Command::getDescription($cmd));
}
$put .= "Usage: {$progname} [options] command [command-options] <parameters>\n" . "Type \"{$progname} help options\" to list all options.\n" . "Type \"{$progname} help shortcuts\" to list all command shortcuts.\n" . "Type \"{$progname} help <command>\" to get the help for the specified command.";
}
fputs($stderr, "{$put}\n");
fclose($stderr);
exit;
}
