Introduction

Abstract

The Unix time-sharing system is rapidly becoming one of the most popular computer operating systems ever designed. Its unique popularity may be the result of portability; Unix systems are available for various different computers, while practically all other operating systems are tied to specific machines. Whether for this reason or any other, the Unix system is becoming universal, much as Fortran became the universal language in its day. And just as Fortran influenced the style of other programming languages, so Unix software characteristics are becoming visible—both by emulation and deliberate avoidance—in other operating systems. For computer users, some acquaintance with the Unix system is therefore taking on increasing importance.