06-08-2013, 04:24 PM
UNIX System Structure & Architecture
AIM:-
To Study Of UNIX System Structure and System Structure.
OBJECTIVE:-
To check how operating system interacts with the underlying H/w & provide the necessary services.
RELEVANCE:
To study how kernel provide services on which all application program in unix system rely.
THEORY:-
System Structure:-
Following fig shows structure of Operating system .The H/W at center provide basic services. The O.S interact directly with H/W. The OS interact directly with the H/W ,providing the common services to programs & insulating them from H/W idiosyncrasies.
System consist of set of Layers , the O.S commonly called as System Kernel. Program such as shell & editor (ed ,vi) shown in outer layer that interact with kernel by invoking the set of system calls .System call interact with kernel & program to due various operation for calling program & exchange data between the kernel & program.
These program called as commands & also private user program may exist in this layer indicated by the program named a.out is a executable file produced by c compiler.
Other application program at outermost layer e.g standard c complier, cc, invoke c processor, complier ,assembler ,loader. Other application program can build on the top of low –level program since it is shown in outermost layer.
Conclusion:
Thus we have seen that how shell is used as interpreter between user & kernel and what is the arch. Of UNIX Operating System.