command interpreter

operating system A program which reads textual commands from

the user or from a file and executes them. Some commands may

be executed directly within the interpreter itself

(e.g. setting variables or control constructs), others may

cause it to load and execute other files.

Unix's command interpreters are known as shells.

When an IBM PC is booted BIOS loads and runs the

MS-DOS command interpreter into memory from file COMMAND.COM

found on a floppy disk or hard disk drive. The commands

that COMMAND.COM recognizes (e.g. COPY, DIR, PRN) are called

internal commands, in contrast to external commands which are

executable files.

(1995-03-16)