} else if ("rm".equals(command)) {
return new RmExe();
} else if ("setattr".equals(command)) {
return new SetAttrExe();
} else if ("info".equals(command)) {
return new InfoExe();
} else if ("cp".equals(command)) {
return new CpExe();
} else if ("mv".equals(command)) {
return new MvExe();
} else if ("echo".equals(command)) {