The OS is a program that uses various data structures. Like 
all programs in execution, you can determine the 
performance and other behavior of the OS by inspecting its 
state - the values stored in its data structures. In this 
part of the assignment, we study some aspects of the 
organization and behavior of a Linux system by observing 
values of kernel data structures exposed through the /proc 
virtual file system. 
The /proc virtual file system: 
Linux uses the /proc file system to collect information 
from kernel data structures. The /proc implementation 
provided with Linux can read many different kernel data 
structures. If you cd to /proc on a Linux machine, you will 
see a number of files and directories at that location. 
Files in this directory subtree each corresponds to some 
kernel data structure. The subdirectories with numeric 
names contain virtual files with information about the 
process whose process ID is the same as the directory name. 
Files in /proc can be read like ordinary ASCII files. You 
can open each file and read it using library routines such 
as fgets() or fscanf(). The proc (5) manual page explains 
the virtual files and their content available through 
the /proc file system. 
Requirements in detail: 
In this part, you are asked to write a program to report 
the behavior of the Linux kernel. Your program should run 
in two different versions. The default version should print 
the following values on stdout: 
•	Processor type
•	Kernel version
•	The amount of memory configured into this computer
•	Amount of time since the system was last booted
A second version of the program should run continuously and 
print lists of the following dynamic values (each value in 
the lists is the average over a specified interval): 
•	The percentage of time the processor(s) spend in 
user mode, system mode, and the percentage of time the 
processor(s) are idle
•	The amount and percentage of available (or free) 
memory
•	The rate (number of sectors per second) of disk 
read/write in the system
•	The rate (number per second) of context switches in 
the kernel
•	The rate (number per second) of process creations 
in the system
If your program (compiled executable) is called proc_parse, 
running it without any parameter should print out 
information required for the first version. Running it with 
two parameters "proc_parse <read_rate> <printout_rate>" 
should print out information required for the second 
version. read_rate represents the time interval between two 
consecutive reads on the /proc file system. printout_rate 
indicates the time interval over which the average values 
should be calculated. Both read_rate and printout_rate are 
in seconds. For instance, proc_parse 2 60 should read 
kernel data structures once every two seconds. It should 
then print out averaged kernel statistics once a minute 
(average of 30 samples). The second version of your program 
doesn't need to terminate.