So, What are the outstanding features of a UNIX Operating System?
• UNIX system kernel is a minimalist approach — the kernel is a single layer of well-chosen primitives (about 64 system calls) which exploit the machine’s resources • It is highly portable — the system call interface is a set of universal rules from which all UNIX systems derive. This means a program or library of programs written on one UNIX system can be easily ported to another UNIX system, which by definitio n must observe the same set of rules. • Built upon the shell are many “small languages” and other “tools” which are designed as “mini-solutions” — building blocks which can be combined and recombined to handle different kinds of system tasks by shell scripts (programs written to be execu ted at the shell level). The shell is the glue for recombining commands and languages. • UNIX provides the user the ability to use the output of one program as input to another. • Since UNIX is written in C, the programmer can request Operating System services from within C programs • It