Mercurial/hg/Repository

• On this date, the class was first taught how to use Mercurial through linux, which will be used as revision control.
• This will allow the class to create and upload files into a database that can be updated at any time. It also allows the class to revisit a previously saved version of a file, and retrieve that file.
• I used revision control in a class before (Structured and Object Oriented Problem Solving) with Joe, but he used www.bitbucket.org, which wasn't the easiest thing to mess with.
• I find that using Mercurial through linux is much easier than in Windows and that unforgiving website, but, overall, revision control is a huge part of programming and is very, very important!

Truth Table

• On this day, we learned about the Truth Table.
• This showed me what each of the possibilities are and what they are represented by.
• I learned about this a little in SOOPS and Computer Essentials, but the new names for each of the different combinations is a first for me.
• I still need to understand what each of those new terms mean and what they represent, as well as memorize most to all of the Truth Table.

• We learned how to use VI/VIM in UNIX/Linux.
• VI (Visual) and VIM (Visual Improved) are both text editors available on UNIX.
• They are very useful because they have many different settings for modifying a file without actually typing in words. The possibilities are ENDLESS!
• With all of the different commands to edit the files through VI/VIM, I am having a difficult time learning and remembering all of the commands and their purposes. I need to practice it more, sometimes I have to resort to using nano, which works for the time being, but VI is so much better!

• In data, I first grasped the concept of Linked Nodes and the program created the previous class.
• The Linked Nodes concept is very similar to the concept of arrays. It takes multiple values and stores them in the order they were input. Linked Nodes just take more to program and make one think more about it. It requires structs, renaming of variables, all sorts of things I wasn't very familiar with before.
• By working on this, I have become more familiar with structs, renaming of variables, and the way that Linked Nodes works in general.
• The nodes themselves can have both a “name” and value or just a value. They could just have a “name”, but what is the point of that when inserting a value and that value actually having meaning? Know what I mean? Anyway, the big understanding I had with the Linked Node program was appending and removing nodes from the list.

Arrays in Shell Script: Fact or Fiction? (Are they different from arrays in C/C++?)

• According to http://www.tldp.org/LDP/abs/html/arrays.html, arrays are created in the same way that they are created in C/C++ programming: array[##]
• It also tells me that it can first introduce an array by the declare -a variable statement.
• To dereference an array, just use curly brackets: ${array[##]}
• Left in the comments were a few pointers (see what I did there?) about arrays: 1) The members of arrays don't need to be consecutive or contiguous. 2) Not all of the members of an array need to be initialized. 3) It is alright to leave gaps in the array (spaces of memory without values).

From the information I have collected, arrays are possible and very similar to arrays in C/C++.

I will create a shell script that will basically perform the same process as the Pointer Assignment Demonstration (http://lab46.corning-cc.edu/opus/fall2012/jcavalu3/part1?#phase_2), and compare the two. This will, hopefully, confirm my hypothesis and allow me to know and understand how arrays work in shell script as well as C/C++ (Nothing wrong with more refreshers!).

The following is the shell script program I created and the results:

  1 #!/bin/bash
  2 #
  3 # You know, just a shell script file for my experiment in opus1
  4 #
  5 # I will create an identical file as the one I used in the pointer
  6 # assignment and check to see if I get the same result.
  7 #
  8 # ONWARD!
  9 
 10 for((i=0;i<4;i++)); do
 11 echo -n "Enter a value (0-9): "
 12 read array1[i]
 13 echo -n "Enter a zero: "
 14 read array2[i]
 15 done
 16 echo "Array1:"
 17 for((i=0;i<4;i++)); do
 18 echo "${array1[i]}"
 19 done
 20 echo "Array2: "
 21 for((i=0;i<4;i++)); do
 22 echo "${array2[i]}"
 23 done
 24 for((i=0;i<4;i++)); do
 25 array2[i]=${array1[i]}
 26 done
 27 echo "Array1:"
 28 for((i=0;i<4;i++)); do
 29 echo "${array1[i]}"
 30 done
 31 echo "Array2: "
 32 for((i=0;i<4;i++)); do
 33 echo "${array2[i]}"
 34 done
 35 echo "Thank you for your time."
 36 exit 0

lab46:~/src/opus/opus1/experiment$ ./array.sh
Enter a value (0-9): 1
Enter a zero: 0
Enter a value (0-9): 2
Enter a zero: 0
Enter a value (0-9): 3
Enter a zero: 0
Enter a value (0-9): 4
Enter a zero: 0
Array1:
1
2
3
4
Array2: 
0
0
0
0
Array1:
1
2
3
4
Array2: 
1
2
3
4
Thank you for your time.

Now, the results from the Pointer Assignment Demonstration:

lab46:~/src/opus/opus1$ ./pa
Please input four values for the first array
1 2 3 4
Here are the values in both arrays:
Array1: 1 2 3 4 
Array2: 0 0 0 0 
Here are the results after setting 'array2' = to 'array1':
Array1: 1 2 3 4 
Array2: 1 2 3 4 

Thank you for your time.

lab46:~/src/opus/opus1$ 

Based on the data collected:

• My hypothesis was correct, I was able to create a program in shell script that performed the same operations that the original Pointer Assignment program did.
• The hypothesis was, indeed, applicable.
• The hypothesis was basically straightforward. Of course, it usually isn't the idea or concept that is different, it is the implementation that is different.
• In the experiment, the shell script was much more difficult to create the same output as the original program created. I was unsure of how to actually have it print each value out in a row, to make it look like it was one large number, as I did in the original. Also, I couldn't just point one array to another and say “You hold the same values as this array now!” I had to dereference the first array to allow the second to take the value that the specific space of memory was holding. If I didn't do that, it would just say “array2[i] = array1[i].” That just isn't what I wanted!
• Shortcomings… are non-existent… in this experiment… Everything went well! I now understand how to declare arrays in shell script, how to dereference them, and how to use pointer assignments in shell script. SUCCESS!

http://beastkong.com/wp-content/uploads/2012/05/success-baby.jpg

What can you ascertain based on the experiment performed and data collected? Document your findings here; make a statement as to any discoveries you've made.

• ON THIS TREMENDOUS DAY, WE LEARNED OF THE BEAUTY OF STACKS (aka STAXX, YO).
• Stacks are very similar to linked list, the access is the big difference.
• In a stack, you can only access the values in it working from the top of the stack to the bottom, instead of grabbing any of the values at any time.
• Stacks help keep things neat, no stabbing at the “pile” and loosing track of things this way!
• I will be working on stacks and creating my own with the help of the linked list program

• So… postfix notation… MIND BLOWN.
• As opposed to infix notation ( (1 + 7) * 6 ), postfix notation lists the operations at the end of the numbers involved. For example:
  • 1 7 + 6 *
  • 5 3 - 2 /
• We were told about this concept with the unveiling of BINARY TREE BOOM!!!!! It is used with stack-based and concatenative programming.
• It is also known as Reverse Polish Notation (RPN).

• I worked with the grep(1) command, which searches through plain text looking for lines that match a regular expression.
• This is nice when you have a file, such as an html file, that has a lot of the html commands present, but you just want what the html file is going to be displaying (The example in class where we reduced the html file from the CCC course page to just the courses and such).
• This command can be used right from the command line or in a program itself (Puzzle Box 2).
• There is another type of grep(1) function that covers extended regular expressions, which is egrep(1).

• I learned that there exists a tremendously hideous but interesting sorting algorithm called Bogo Sort.
• The way Bogo Sort works is it takes a set of numbers, basically “throws them up in the air and however they land” is your new set, if the numbers aren't in numerical order, then the set will repeat the process and check again. This is done until the set is in correct numerical order.
• This sorting algorithm is very inconvenient, can be finished within the first ten tries or never even complete, and can use up a great amount of memory.
• However, it is very interesting knowing how it works and seeing how long and how many tries it takes to find the correct sort.

I downloaded VirtualBox and Debian to run on it, but when everything was installed, the possible resolutions were not available to me. I am going to experiment with it and figure out how to fix it.

I installed it with the help of Evan Olson, but the rest of my help will come from the internet and whatever I can find. Any websites used will be listed below:

• http://www.calebscreek.com/2010/08/how-to-install-virtualbox-ose-guest-additions-in-debian-testing-squeeze/
• http://community.linuxmint.com/tutorial/view/739

I believe that I will need to install packages for the resolution. I don't think there will be much more to it, maybe some command line arguments to actually use the packages or something along those lines.

I will research VirtualBox and Debian and find how to fix the problems. I will document my research and experiment in the data section below with the use of screenshots and such!

Well, the first problem I ran into was that I wasn't a sudo user, so with your help, I made myself one by going to the terminal, going to the root command prompt, accessing the visudo file, and adding myself as a user. From there, I typed in sudo apt-get install virtualbox-ose-guest-x11, which, I think, installed the Guest Addition Driver X11. I ended up getting a larger resolution (1024 x 768) instead of the monitor's natural resolution (1600 x 900). I tried the other website's tactics, which were to update Debian, remove the OSE guest additions using sudo apt-get remove virtualbox-ose-guest* and then mounted the VBOXADDITIONS ISO by using the command sudo sh /media/cdrom/VBoxLinuxAdditions.run.

Based on the data collected:

• Yes, but it isn't working very well. I still haven't been able to use the correct resolution.
• I couldn't get past the 1024 x 768 resolution, even when I tried the things I was told to try on the websites, and I can't think anymore! I'm too tired!
• I probably could have tried more, but I am going to do that tomorrow when I come in before class starts.
• The data showed a change in resolutions, it was a better resolution than the one that I started with, but it isn't the best and I can find the best.

I can conclude that I have an extremely hard time messing around with operating systems and it is a lot harder than I thought it would be.

• On this day, I learned about head and tail.
• Both are regular expressions used to access different areas of a file.
• The expression head is used to access the top of a file, it can be manipulated with other commands to access certain amounts of the beginning.
• The expression tail is used to access the bottom of a file, it can also be manipulated with other commands but it will access specific amounts in the bottom.
• One can also use them together to access even more specific data in a file.

• We were told more in-depth about Makefiles.
• Makefiles are used to make compiling, copying the directory and other useful command line activities easier by typing in one or two words on the command line.
• Some of the commands are copy, make, make debug, make poop (NOT), many other funstuffs!
• It is a script file that just reads the file names in the directory in a lot of cases and puts them in for compiling, copying, etc.

• The GD LIBRARY!!!!
• The gd Library is used to create some sort of graphic output using programming languages and compiling those files.
• The file given to us was a pac-man like image with a border, a rectangle on the bottom and a web-URL. With that, we were able to manipulate it and create a CCC logo just the other day.
• There are many functions available to programmers, but the only relevant ones that I have used so far are the arc function, rectangle function, and line function.

• Binary Tree Fun Stuff!
• The binary tree is used to sort a queue of values in numerical order.
• There are multiple ways of implementing the binary tree, we are tasked with creating an iterative method, recursive method, and stack method of sorting. Each will probably use the left-parent-right method.
• The left-parent-right method: taking values in a queue, comparing them along the list, then moving all the way to the left and inputting the value into that node. Next, it will move to the parent node and input the next largest value. From there, it will move to the right and input the next largest value. The program will then shift back to the left, input the next largest value, then to the parent, then to the right, until it hits the middle of the queue, then it will move to the right, then the left and input the next largest value there, then to the parent, input the value, until the end of the queue is reached.

For my final experiment of the semester, I took a computer from the LAIR and put all of the necessary parts back into it (hard drive, RAM) so I could have a computer of my own to work with during the upcoming semesters.

I received help from Tom and Evan when I put the computer together. I put my desktop computer together during the summer of 2011, but I received help from a good friend of mine and I didn't really pay much attention to what went where and how it all worked, which is why I wanted to do this, so I could get a better understanding of how things go inside of a computer.

I believe that this will be a good learning experience for me. Like I had previously stated, I need to understand the inner workings of a computer more and I feel as if this is a good start.

I am going to take a computer down in the LAIR that doesn't have all of the necessary components to run and fix it up so that it can. (The computer already has a CPU inside of it and, seeing as how I accidentally messed up my old desktop's CPU when trying to clean it out, I figure that I won't bother taking it out and putting it back in, I'll just explain its purpose without showing its installment).

The modern computer begins with the computer case. Every computer has a case to protect it from dust, dirt, fur, getting kicked, holds the power supply, motherboard in most cases comes with a usb port or two, and any other drives like the CD/DVD drive, floppy disk drive, etc.

The following is a picture of the case opened up:

The next piece of hardware that should be installed is the power supply. The power supply, as you probably could have guessed, gives all of the other hardware inside of the case power so that it can function. Power supplies range in the amount of power they put out.

The following is a picture of the power supply already installed:

Next, the motherboard should be installed into the case. The motherboard connects the circuit between all of the hardware in the case. In many cases, motherboards can come with integrated graphics, networking, audio, although the integrated hardware is not as powerful as the card counterparts (graphics cards, sound cards, network cards, etc.)

Directly connected to the motherboard are the CPU and the RAM.

• The CPU is what performs the basic arithmetic, logical and input/output operations of the instructions of the computer programs being run.

The following is a picture of the CPU covered with a heat sink which cools the CPU due to all of the processes and currents running through the CPU:

• The RAM is used to access memory in any storage location at any time quicker than hard drives, CDs, etc.

The following is a picture of RAM connected to the motherboard:

The hard drive is the final necessary piece of hardware for the computer to run correctly. The hard drive is the storage for the computer and allows the RAM to access it whenever it is needed.

The following is a picture of the installed hard drive:

With all of the hardware installed, the computer did work, however, I found a better computer and I am using it now, so I uninstalled the hardware for others to use. But here is a picture of the hard drive and RAM before it was installed:

Based on the data collected:

• I learned more about how the hardware is installed and it was a grand 'ol time!
• I had a bit of an understanding of the computer hardware from classes I have taken and when I put together my own computer, but it was nice to have a quick refresher on the hardware and it's purpose.
• Due to the computer having a few things like the power supply, a floppy disk drive, the motherboard and the CPU already installed, I didn't actually get to install everything myself, but since I described each piece of hardware's function, I know more about it all.
• I wanted to check the hard drive and see if there was an operating system on it or anything but the new computers came in and I didn't get that far before I picked another computer.

What can you ascertain based on the experiment performed and data collected? Document your findings here; make a statement as to any discoveries you've made.

• Not only do I find programming to be enjoyable, but now I realize that I am interested in the separate pieces of the computer itself and not just the programs that run it. I really want to experiment more with computers and get more of an understanding of all of it.