void main( string arg ) {

  arg = normalize_path( arg, this_player()->query_env( "cwd" ) );

  if( arg == "" ) {
    write( "Access denied.\n" );
    return;
  }
  
  if( strlen(arg) > 1 && arg[strlen(arg)-1] == '/' ) {
    arg = arg[..strlen(arg)-2];
  }
    
  if( file_exists( arg ) != -1 ) {
    write( "Dir not found.\n" );
    return;
  }

  this_player()->set_env( "pwd", this_player()->query_env( "cwd" ) );

  this_player()->set_env( "cwd", arg );
  write( "%^BOLD%^" + this_player()->query_env( "cwd" ) + "%^RESET%^\n" );
}