| 摘要 |
<p>Multiple versions of a given system command are run on a single operating system by using one command processing program per command irrespective of its version. Each version of the command has a command definition which has the same format for all counterparts of the command. A command analyzer program (36) transforms the parameters of a command character string into the correct data form for its command processing program based on the command definition for that version of the command. Multiple sets of command definitions are place in separate storage directories called libraries (12, 14, 15). The libraries are searched based on a version identifier to find the command definition for a command. The version identifier may be specified as a program attribute, entered interactively or entered by the system. Multiple programs written with different versions of commands may be run in conjunction with each other and the system will dynamically adapt to the version of each program as it is running. Also more than one command definition library may be searched to process a command. Therefore, commands written in various versions may be embedded in the same program and the system will dynamically adapt to multiple versions of commands in a program.</p> |
