COMP3500 - IntroductiontoOperating SystemsProject 1 - Using the Linux TerminalVersion 3.0 -Solved

Objectives:  

•      Get to know the Linux operating system

•      Learn basic Linux commands

•      Prepare a Linux programming environment for the future COMP3500 projects

•      Learn how to remotely access Linux servers (see Option 1 below).

•      Learn how to install VirtualBox and CentOS (see Option 2 below).

•      Compile and debug your first C program in Linux

 

1.   Setup Linux Programming Environment (10 Points)
 Important!  When you access a remote Linux machine in the Linux lab (i.e., Option 1), please don't use the "sudo" command, because you have no administrative rights. If you choose options 2-4, you may use the "sudo" command on your virtual machine or local machine where you are a system admin.

 

You should choose one of the following four options to setup your Linux programming environment.

 

1.1 Option 1: Remotely Connect to Linux Machines (Difficulty Level: ê)

Please follow the instructions specified in “Project 1 Option 1 Remotely Connect to Linux Machines.pdf” to learn how to access a remote Linux server. You must keep in mind that when you access a remote Linux machine in the Linux lab, please don't use the "sudo" command.

 

1.2 Option 2:  Install VirtualBox and CentOS (Difficulty Level: êê)

Please follow the instructions specified in “Project 1 Option 2 Install VirtualBox and CentOS.pdf” to learn a way of installing VirtualBox and CentOS in your own laptop or desktop computers.

 

1.3 Option 3: Install CentOS on a PC in the OS laboratory (i.e., Shelby 2129). (Difficulty

Level: êê)

•      Obtain a CentOS CD or download CentOS o You may stop by Dr. Qin’s office during his office hours (MWF 1:00-2:00 p.m.) to pick up a CentOS CD.

o You may download the CentOS from the following web link: http://mirrors.tummy.com/mirrors/CentOS/7/ 

•      Insert your CD and reboot the system, press direction key to enter the next booting page.

•      Enter “Welcome to centos-7-x86_64-LiveCD” page, choose install.

•      Choose “Basic Storage Devices” for the device and “Use All Space” for the partition.

•      After you reboot the computer, please follow the steps to finish the configuration.

•      Open a terminal and do “yum -y update” to update all the packages. You need to be the root to do this.   

•      Please make sure the following packages are installed: gcc, gcc-c++, vimenhanced, emacs gdb, ethtool, hdparm, file and pciutils. They most likely are already installed. You can run the following commands to confirm their availability and install as needed.

$yum -y install gcc 

$yum -y install gcc-c++ 

$yum -y install vim-enhanced  

$yum -y install emacs 

$yum -y install gdb 

$yum -y install ethtool 

$yum -y install hdparm  

$yum -y install pciutils  

$yum -y install file  

 

1.4 Option 4: Dual-boot Linux and Windows (Difficulty Level: êêê)

If you choose this option to dual boot Linux and Windows 10 on your own computer, please follow the instructions here: https://itsfoss.com/guide-install-linux-mint-16-dual-boot-windows/ 

2. The script Command
The script command line tool allows you to save a session of your terminal. In addition to saving each command per line in a text file, the script command makes a typescript of everything that happens on your Linux terminal. Screencasting tools to a desktop session(GUI) is what script is to a terminal. Let us demonstrate the usage of script through the following example:

$ script 

$Script started, file is typescript 

$ cd $ ls 

file1 file2 file3 

$ exit exit Script done, file is typescript 

Then, you may use the mv command to change the file name from typescript to any name you like. Alternatively, you may specify the name of your log file upfront as below:

$ script sample.script 

$Script started, file is typescript 

$ cd $ ls 

file1 file2 file3 

$ exit exit 

Script done, file is sample.script 

 

3.   Tasks (90 Points)
Script the following session using the script command. You may save each session  (i.e., each task below) in one script file. Using the tar command to submit a tarred and compressed file named project1.tgz (see Section 4.2 for details).

 

3.1 (Task 1: 25 points. Difficulty Level: ê) Please use the script command to create a file named “commands.script” demonstrating that you understand how to use the following basic Linux commands.

 

•      man [command] – displays the help information for the specified command.

•      cd – changes a directory.

•      pwd – displays the pathname for the current directory.

•      ls – lists the files in the current directory.

•      mkdir – makes a new directory.

•      cp – copies a file from one location to another.

•      mv – moves a file from one location to another.

•      rm – removes a file.

•      rmdir [options] directory – deletes empty directories.

•      chmod [options] mode filename – changes a file’s permissions.

•      clear – clears a command line screen/window for a fresh start.

•      top – displays the resources being used on your system. Press q to exit.

•      who [options] – displays who is logged on.

•      nproc – displays the number of cores.

 

Reference: How to Start Using the Linux Terminal https://www.howtogeek.com/140679/beginner-geek-how-to-start-using-the-linuxterminal/ 

 

 3.2 (Task 2: 10 points. Difficulty Level:    ) When you log in a Linux system, you should get to know the system in more detail. You are asked to find out your computer system’s attributes, including CPU frequency, cache size, memory size, the list of PCI devices, hard drive, network MAC address and link speed, and the devices generating interrupts. The following system commands can help you. Many of these commands are for system administration, so you should run them as root if needed.

 

$more /proc/cpuinfo 

$more /proc/meminfo 

$more /proc/interrupts 

$lspci 

 

Tip: You may pipe the output of any Linux command to a file on Linux. For example:

   #ls > test.txt 

The above command writes all files in the current directory to a file called “test.txt” instead of displaying the files on a monitor.  

 

Please store the output from the above four commands into the following four files using the pipe (see the above tip).  

•      cpuinfo.txt 

•      meminfo.txt 

•      lspci.txt 

•      interrupts.txt 

 

3.3 (Task 3: 30 points. Difficulty Level: êê) With the computer up and running, you should give it a try to see if you can use the utilities on the system. For a system programmer, these include at least the editor, the compiler, the libraries, and the debugger. You are asked to do the following

3.3.1.      Using your favorite editor, code a program (simple.c) that processes an array of 10 numbers, calculates the average of their square roots, and prints it out. I recommend either emacs or vim (a.k.a., vi) as an editor for COMP 3500. If you are not yet proficient with either of them, you should be able to type the simple.c program without too much effort.

 

3.3.2.      The GNU compile is the default open source compiler on Linux. You should check a little on what gcc you have, and then compile your program as follows. Please do not forget the flag ‘-g’ for using debugger in Step 4.  

             

                        $gcc -v 

          $gcc -g -lm -o simple simple.c 

 

3.3.3        Practice the command ldd, and understand the libraries on which your program is dependent upon for execution.

             

                        $man ldd 

          $ldd simple 

 

3.3.4        The debugger is a friend you must get acquainted with to be a good programmer. Here is a little trick in using the GNU gdb debugger.  

(1)  First run your program, simple, alone

(2)  Prepare a file name as .gdbinit in the current directory with the following content:

 

file simple break main break sqrt info registers 

 

(3)  Run the gdb debugger and then type these characters (‘r’, ‘s’, ‘n’, and ‘c’), one at a time complete the program

 

# gdb 

# r 

# n 

# s 

# c 

 

3.3.5 Your project report should include the source program, and the output from Steps (1)-(4).

  

3.4  (Task 4: 25 points. Difficulty Level: êê    ) Now you should learn how to use git – a version control system - to manage your software development conducted by your future groups. An online book focusing on git can be found here: https://gitscm.com/book/en/v2.

Note Important! : You must make use of the script command (see Section 2 page 3) to save a session for task 4. The script file name should be “git.script”.  

 

3.4.1  Install git  

 Important!  This step is required for Options 2, 3, and 4 only. If you choose option 1, please skip this step and directly go to 3.4.2.

$ sudo yum install git 

 

Reference: https://www.linode.com/docs/development/version-control/howto-install-git-on-linux-mac-and-windows/ 

 

 Important!  Please refer to the following webpage for detailed instructions on Steps 3.4.2-3.4.9.

https://git-scm.com/book/en/v2/Git-Basics-Recording-Changes-to-the-Repository 

 

3.4.2  Initializing a Repository in an Existing Directory. We assume that you have created a directory “comp3500/project1” in your home directory.

$cd ~/comp3500/project1 

 

If you want to start version-controlling existing files (as opposed to an empty directory), you should probably begin tracking those files and do an initial commit. You can accomplish that with a few git add commands that specify the files you want to track, followed by a git commit:

$git init 

$touch cpu.c 

$touch driver.c 

$touch file.c 

$git status 

$git add *.c 

$git status 

$git commit -m 'Initial project 1' 

$git status 

$rm cpu.c 

$ls 

$git checkout cpu.c 

$git checkout -b master2 

$touch cpu2.c 

$git add cpu2.c 

$git commit -m ‘cpu2 is added into master 2’ 

$git branch 

$ls 

$git checkout master 

$ls 

$git clone -b master . ../new_project1 $cd .. 

$ls 

$cd new_project1 

 

3.4.3 Cloning an Existing Repository

You clone a repository with git clone <url>. For example, if you want to clone the Git linkable library called libgit2, you can do so like this:

$git clone https://github.com/libgit2/libgit2 

 

That creates a directory named libgit2, initializes a .git directory inside it, pulls down all the data for that repository, and checks out a working copy of the latest version. If you go into the new libgit2 directory that was just created, you’ll see the project files in there, ready to be worked on or used. If you want to clone the repository into a directory named something other than libgit2, you can specify the new directory name as an additional argument:

 

$git clone https://github.com/libgit2/libgit2 mylibgit 

 

3.4.4 Checking the Status of Your Files:

$git status 

 

3.4.5 Tracking New Files

In order to begin tracking a new file, you use the command git add. To begin tracking the README file, you can run this:

$git add README 

 

3.4.6 Staging Modified Files

Now we change a file that was already tracked. If you change a previously tracked file called CONTRIBUTING.md and then run your git status command again.

 

 

3.4.7 Viewing Your Staged and Unstaged Changes

If the git status command is too vague for you — you want to know exactly what you changed, not just which files were changed — you can use the git diff command.

 

$git diff 

 

3.4.8 Committing Your Changes

Now that your staging area is set up the way you want it, you can commit your changes. Remember that anything that is still unstaged — any files you have created or modified that you haven’t run git add on since you edited them —  won’t go into this commit. They will stay as modified files on your disk. In this case, let’s say that the last time you ran git status, you saw that everything was staged, so you’re ready to commit your changes. The simplest way to commit is to type git commit:

 

$git commit 

 

3.4.9 Viewing the Commit History

The most basic and powerful tool to do this is the git log command.

 

$git log 


  

4.1  A single File
Please submit your project report with needed contents as specified in the questions (see Section 3). You must submit your report through Canvas (no e-mail submission is accepted.  Please report any problems you have solved when you learn Linux commands and git.

 

The file name should be formatted as:  

                   “project1.pdf”  

 

4.2  Multiple Script Files
If you have generated multiple script files, please save all the script files in one directory say (project1). Then, you should achieve all the script files along with your report and the source code (i.e., simple.c) into a single tarred and compressed file. Assume that the script files and your report are located in ~/comp3500/project1, then you can follow the instructions below to prepare a single compressed file.

 

%tar vfcz project1.tgz ~/comp3500/project1