A comparative study of four operating-systems command-language m̀acrosʹ

The Power Systems Technology Program at Oak Ridge is undertaking a project in Computer-Aided Control System Design (CACSD). The objective of the project is the specification of requirements for CACSD computer software.

The purpose of this study was to recommend a command language for CACSD software. The command language should parallel the capabilities given a user writing in the implementation language. The purpose of the command language is to allow the one-time solution of problems without requiring the detail of the implementation language. A good command language with macro capability was needed. This study was conducted considering the command languages which are applicable in CACSD packages. Four operating systems, RT-11, TOPS-10, VM/CMS and UNIX, were considered.

In order to find out about the desired command language, it was necessary to first understand the command languages of these operating systems with emphasis on combining a sequence of commands into a unit. This unit may be substituted as a 'macro' or invoked as a sub-routine, probably with parameterization. This macro facility is available with RT-11 as 'Indirect command files,' TOPS-10 as 'MIC,' with CMS as 'EXECS,' and with UNIX as 'SHELL.'

A comparison is made between these operating-system command language 'macros' or procedures.