Homework #3: Full hierarchy of processes

CSE-381: Systems 2
Homework #3: Part B

Maximum Points for This Part: 25
Objective
The objective of this part of the homework is to develop 1 C++ program to:
• Print process hierarchy for a given PID (process ID)
• Gain familiarity with developing a C++ class
• Continue to gain familiarity with development and testing of C++ programs
• Continue to bolster concepts of stream/file processing.
• Review basics of string processing & problem solving
• Continue to gain familiarity with the use of std::unordered_map
Submission Instructions
This part of the homework assignment must be turned-in electronically via Canvas using the
CODE plugin. See video for using the plug-in at: https://youtu.be/P2bWUt5KqbU. Ensure your
program compiles without any warnings or style violations. Ensure you have tested operations of
your program as indicated. Once you have tested your implementation, upload the following
onto Canvas:
• Just the one C++ header file and 1 C++ source file with the naming convention
MUID_hw3.h and MUID_hw3.cpp, where MUID is your Miami unique ID.
General Note: Upload each file associated with homework (or lab exercises) individually to
Canvas. Do not upload archive file formats such as zip/tar/gz/7zip/rar etc.
Grading Rubric:
The programs submitted for this homework must pass necessary base
case test(s) in order to qualify for earning any score at all.
Programs that do not meet base case requirements will be assigned
zero score!
Program that do not compile, have a method longer than 25 lines,
or just some skeleton code will be assigned zero score.
• Base case points: 5 points
• Additional tests: 15 points
• Overall C++ class design, code quality, design, code reuse, documentation etc.: 5
points. These points are typically the hardest to earn in more advanced courses.
DUE DATE: Tue, September 18 2018 Before 11:59 PM (EST)
Page 2 of 3
Develop a C++ program to print full process hierarchy
Objective
The objective of this program (developed as a C++ class) is to print the full hierarchy of
processes (starting with /sbin/init) for a given PID (process ID, specified as a command-line
argument). The data about processes is read from a given text file (as command-line argument).
 Essentially this program automates the manual process of tracing the Linux process
hierarchy that was done as part of an earlier lab exercise. Refer to the earlier lab
exercise of using the output of ps -fe to trace processes to recollect the manual
process of tracing the process hierarchy.
Background
In Linux, processes are organized as a tree, rooted at /sbin/init, which is the first process
that the Linux kernel starts running. Each process is identified by a unique ID called PID (short
for process ID). Furthermore, each process has a PPID (short for parent process ID). The process
hierarchy can be determined manually, by recursively tracing the PPID in the output of ps -fe
command. However, this program is designed to automate this task of tracing the process
hierarchy.
Data file formats
Prior to solving any problem is important to study the supplied data. So ensure you view the data
files (yes, of course you can do this in NetBeans). The supplied data files are exactly the
output of ps -fe command, also reviewed in lab exercise(s).
Program requirements & Tips:
• This program should be developed as a C++ class with the following 2 files:
o MUID_hw3.h: This header file should contain the class declaration. You will
need 2 public methods –  a method that loads process data from a given file into
2 unordered maps (discussed below)  a method that prints the process tree for a
given PID. You may add any private helper methods as you see fit. It is up to you
to decide meaningful names for methods and their arguments.
o MUID_hw3.cpp: This source file should contain the implementation for the
methods you have defined in the header file (ensure you #include
"MUID_hw3.h" in your source file). This file will also contain the
implementation for the main method. Your main method should create an object
and calls methods on the object with suitable parameters.
• To ease printing the process hierarchy, in your class use 2 unordered_maps as
instance variables in your class to store the following:
1. pid⇔ppid information to ease look-up of parent process ID.
2. pid⇔cmd information to ease look-up the command associated with a PID.
• Use std::istringstream to process each line. Even if you don't use a specific
column of data, it is still easier to read it and simply not use it.
DUE DATE: Tue, September 18 2018 Before 11:59 PM (EST)
Page 3 of 3
• Note the order in which processes are listed in the sample output. It is top-down (and not
bottom-up)
• For printing the process hierarchy in a top-down manner, you may use an iterative or a
recursive solution as you see fit. However, the recursive solution will most likely be
shorter than an iterative solution.
Sample outputs
One you have completed your program, you can test its operation using the command shows
below and compare your output to the output shown below. Note that for the 3 column output,
each column is separated by 1 tab (i.e., "PID\tPPID\tCMD") character
Base case #1:
$ ./raodm_hw3 proc_info1.txt 1
Process tree for PID: 1
PID PPID CMD
1 0 /sbin/init
Test case #2 [Must pass to earn full points]:
$ ./raodm_hw3 proc_info1.txt 27426
Process tree for PID: 27426
PID PPID CMD
1 0 /sbin/init
949 1 /usr/sbin/sshd -D
27282 949 sshd: salvucwa [priv]
27323 27282 sshd: salvucwa@pts/31
27324 27323 -bash
27425 27324 script
27426 27425 bash -i
Test case #3 [Must pass to earn full points]:
$ ./raodm_hw3 proc_info1.txt 27535
Process tree for PID: 27535
PID PPID CMD
1 0 /sbin/init
949 1 /usr/sbin/sshd -D
25640 949 sshd: raodm [priv]
25681 25640 sshd: raodm@pts/22
25697 25681 -bash
27535 25697 ps -fe
Submit to Canvas
This homework assignment must be turned-in electronically via Canvas via the CODE Plugin.
Ensure your program compiles without any warnings or style violations and operates correctly, at
least for the base case. Once you have tested your implementation, upload just one C++ source
file via the CODE plugin.