$1.(15)$ Briefly describe the semantics of the Unix system calls listed below. Place your descriptions in a

plain text file named syscalls.txt

a$.$ getpid$()$;

b$.$ getppid$()$;

c$.$ open$()$;

d$.$ read$()$;

e$.$ write$()$;

f$.$ close$()$;

g$.$ chmod$()$;

$2.(20)$ Write a program that uses each of the above system calls at least once. Comment your code and

submit it in a file named syscalls.cpp

$3.(20)$ Consider the evolution of computers in general and the increase in processor speed in particular.

Suppose we were to design a system with a processor that is clocked at $3$GHz$.$ Further, let us suppose

that signals in our system can propagate at $80\%$ of the speed of light. Determine the maximum

distance between the CPU and Memory $($or Cache$)$ if we want to access data within one processor

cycle. Provide your answer and a description of how you arrived at this answer in a plain text file

named length.txt$.$

$4.(45)$ Write a small program that copies data from a file A to a file B$.$ For different file sizes $1$KB $128$MB

$($doubling the file size in each step$).$ So$,$ you will create $18$ different files with files sizes $1$KB$,2$KB$,4$ KB$,$

$8$KB and so on$.$ Record the time your program requires to complete the copy when using read$()$ and

write$()$ system calls for each byte that is being copied. Generate a graph that depicts the program

performance $($you can create a graph in excel$).$ In the graph, x$-$axis should be different number of file

sizes and y$-$axis should be the total time $($in seconds$)$ to complete copying files.

Briefly describe what you observe and investigate if you can improve the program$$s performance. For

this program it is imperative that file A and file B are located on the local disk. For submission,

a$)$ Provide your source code in a file named copying.cpp

$$ Note: you must use system calls $($read and write$)$ otherwise you will not get the points.

$$ Your program should take file names $($source and destination$)$ from the command line

and do not hard code the file names.

$$ Add error handling codes such as file not available, error opening files etc.

$$ Add comments in your code.

b$)$ Provide your graph in a file named copying.jpg

c$)$ Provide your description in a file named copying.txt

Note that you may use truncate command in Linux to create dummy files with specific file sizes. Also,

you can use time command in Linux to collect exact time taken by your program to complete

execution.