Mechanism for enabling emulation system users to directly invoke a number of host system facilities for executing host procedures either synchronously or asynchronously in a secure manner through automatically created shell mechanisms

A host system having a memory organized into shared and host memory areas and a hardware platform including a plurality of input/output drivers operatively connected for executing host system instructions and for emulating the execution of emulated system instructions by an emulator running as an application process on said host system, said plurality of input/output drivers including terminal drivers, said emulator including a number of emulated system executive service components operating in said shared memory area comprising a command handler unit and an interpreter, an emulator monitor call unit (EMCU) and server facilities operating in said host memory area, said host system further including operating system facilities for providing a number of services for host programs, said operating system facilities being coupled to said plurality of input/output drivers and to said EMCU, said host system further including a terminal based facility for invoking host system facilities by a number of terminal based dual decor commands, said terminal based facility comprising:

• a shared terminal based command handler means included within said command handler unit, said command handler means responsive to any one of said number of dual decor commands generating a special monitor call to said EMCU for causing a request input/output operation to be issued to said server facilities;
• a user table (USTBL) mechanism located in said host memory area, said USTBL mechanism having a number of locations for storing unique user description entries generated by said EMCU for emulated system users whose identities were previously validated during login;
• and,
• said server facilities including network terminal driver (NTD) server means operatively connected to said terminal drivers, said NTD server means including user security validation means, said security validation means in response to input/output request generated by said terminal based command handler means in response to one of said number of terminal based dual decor commands, performing a validation operation on said emulated system user identity by accessing said user table mechanism entry associated with said user requesting access to ascertain that said command was issued by a trusted user and would not compromise host system security.