Eric Scouten's Fall2012 Opus
I'm Eric Scouten, born and raised in Hornell, NY. I've been familiar with computers since I was a toddler due to my fathers huge interest in them; I've been working with computers on a technical level since I was 14 and built my first tower when I was 15, still using it today. My pursuits are to simply do very well in the subjects I've been taught and continue to expand my knowledge of them indefinitely. My interest in computers has brought me to want to work as a technical director for businesses, as well as a growing interest in the High-Performance Computing sector. As a side interest, I hope to also open up a radio station(broadcasting and internet) of my own for the local areas and internet.
My hobbies include video gaming, guitar, and longboarding. My favorite movie of all time is The Princess Bride. My musical interests are hard rock to melodic death metal; to instrumentals and electonica.
And I'm a proud geek.
The UNIX Philosophy
We also went over file types and file paths, which is mostly covered as my keyword. There are two different file paths, an absolute path and a relative path.
An absolute path looks like this if you change directory: cd /home/name/src
A relative path would look something like this: cd src
That relative path would only work if you were in the /home/name directory (confirming that using the pmd command)
/lib - library files/functions. Libraries hold and reference to many smaller programs. ldd - command that lists the necessary functions to perform a command.
libc is the standard C library
/media - Directory for mounting file systems on removable media like CD-ROM drives, floppy disks, and Zip drives.
/mnt - where removable devices or temporary file systems are placed upon plug-in. Such as flash drives.
“Vi (pronounce: “vee eye”, not “six”, not “vye”) is an editor. An editor is a program to edit files. Goodbye.”
To launch Vi, just use the vi command. Use vi with a filename after it to open a file, in Vi Two modes..
Here are a few commands in no special order..
The colon : is extended command mode, which has some notable commands..
This day we went over the archiving and compression commands known as tar, which is the archiver and gzip, the compressor. The neat thing about having two commands for this process, you have the option to do one or the other, or both. If you've seen a .zip file before, that is an extension that indicates it was compressed AND archived. That limitation is that you cannot have one or the other through the means of a Windows program like WinZip or 7Zip. tar by definition, saves many files together into a single tape or disk archive and can restore individual files from the archive. Some worthy extensions may include..
gzip is the compression/decompression tool that is often used after archiving a file. Use gzip [filename] to compress your file Some worthy extensions that should be used accordingly..
In class we also went over the command last and eventually learned how to get personalized information through a super incantation.
The command last lists all the logins for a complete month, in the case of this day, it listed all the logins from the month of September. This will reset once it has become October. You can imagine this being a very hectic, long list but luckily we have some ways to get the information we need.
We can use a pager command such as more which will show a “page” full of lines being generated, and you press space to move onto the next page. You can also use less to list these pages in reverse (from the beginning of the month to end).
A command with the more or less commands must be an incantation through the use of the pipe | . Which would look something like this: last|more or last|less This can be useful but we want more specific information from the last command so we created a super incantation, which is the following.. echo “You logged in `last|grep $USER|wc -l` times this month” To break this down..
On the current day (9/30/2012), this incantation displays You logged in 28 times this month. This is really cool and all, but imagine if you had to type that every time you wanted to know how many times you've logged in? Let's get lazy!
We next learned how to make any file an executable or program. We can use the incantation we created above and just type it up into a file, or you can be even lazier, and type the incantation and direct its output into a new file by using a full quotation and adding another echo, like so: echo 'echo “You logged in `last|grep $USER|wc -l` times this month”' > login
This will display our incantation into a new file known as login or overwrite the existing file login.
And finally to make this a working program, we need to change the permissions which can be viewed using ls -l.
To change permissions, use the command chmod with the corresponding numbers 744: chmod 744 login
This will make our file a program and you can just run it using ./login assuming you are in the same folder, otherwise change the path accordingly.
The Regular, Directory, and Special File Types
Unlike most keywords, this one isn't just one simple keyword. A file type is a vague term that represents files, and in order to really know what one is, they should be defined, SUCH AS:
An important consideration when we're talking files is that each file has permissions for them that determine which users can Read, Write, or Execute a file. These are formally known as access modes. These access modes are often represented in this format: Eg. drwxrwxr– or srwxr—–
ls is a command for directory listing. What this mean is it lists all the contents of the directory in a curt manner. Usually just the names of the directories, files, and their file types by color coordination.
Home Directory
The Home Directory is basically the place that all of a user's files and folders are stored. From the home directory, one may be able to access all of their files, or just access specifically places files. The user is able to completely customize their home directory. When files and folders are in a home directory (including readable, writable, and executable files), they are only able to be accessed by the user or any other administrator on the system. That can be changed at any point, however.
Firstly, we identify where the home directory is. When you log in, you should be able to use the pwd command and boom, you it shows the absolute path of your home directory. Another way to ensure that it is YOUR home directory, you can use pwd $USER and the same result should display. Try that in another relative directory and you will get the same result every time, because $USER represents your username, which is mainly used to identify your home directory.
We can also change directory or cd to your home directory using an absolute path or a relative path if you are in the /home directory.
The home directory is the one directory where it's not recommended to even consider changing the Owner access controls.
One of the most useful things you can do related to your home directory is usage of the cd command in order to quickly return to it, from anywhere in the file system, including finding your way into another user's home directory, you can easily change back to yours with simply cd
And finally you can use ls to see what it looks like to verify that they are your directories.
Assume your username is rabidrabbit
Back to back demonstration..
lab46:~$ pwd /home/rabidrabbit lab46:~$ pwd $USER /home/rabidrabbit lab46:~$ cd / lab46:/$ cd /home/$USER lab46:~$ pwd /home/rabidrabbit lab46:~/src/submit$ cd lab46:~$ pwd /home/rabidrabbit lab46:~$ cd /home/tmong lab46:/home/tmong$ cd lab46:~$ pwd /home/rabidrabbit lab46:~$ ls Desktop Downloads Music Public Videos closet file.txt src Documents Maildir Pictures Templates archives data public_html
I notice we always archive a group of files before we compress. What would happen if we compressed these files individually first, then we archived them, would it still give us the same outcome?
I'll be using the information I learned from class to generate some sort of outcome from this, using the tar and gzip commands exclusively. Most of this information can be referred to my dated entries in this Opus.
I think that this will work normally. The archiving before compression feels like a good practice but doing it the other way feels taboo. At the end of this experiment, I think we will have the same files we created.
I plan on creating a directory for this experiment, to keep all my other stuff safe. Then I'll use the touch command to create 3 files and type in some information in them. Instead of normally using tar first, I'll proceed to compress each of these files, then I'll select them all for archiving. Once that is completed, I'll proceed to reverse this process and hopefully have the same 3 files and the information within them in tact.
lab46:~/closet$ mkdir thelab lab46:~/closet$ cd thelab lab46:~/closet/thelab$ touch file1 file2 file3 lab46:~/closet/thelab$ ls file1 file2 file3 lab46:~/closet/thelab$ vi file1 lab46:~/closet/thelab$ vi file2 lab46:~/closet/thelab$ vi file3 lab46:~/closet/thelab$ cat file1 This is file 1 lab46:~/closet/thelab$ cat file2 This is not file 1 or file 3 lab46:~/closet/thelab$ cat file3 file 3 this is. lab46:~/closet/thelab$ gzip file1 file2 file3 lab46:~/closet/thelab$ ls file1.gz file2.gz file3.gz lab46:~/closet/thelab$ tar cvf archive.tar file1.gz file2.gz file3.gz file1.gz file2.gz file3.gz lab46:~/closet/thelab$ tar tvf archive.tar -rw-r--r-- escoute1/lab46 39 2012-09-30 17:17 file1.gz -rw-r--r-- escoute1/lab46 49 2012-09-30 17:09 file2.gz -rw-r--r-- escoute1/lab46 42 2012-09-30 17:09 file3.gz lab46:~/closet/thelab$ rm file1.gz file2.gz file3.gz lab46:~/closet/thelab$ ls archive.tar lab46:~/closet/thelab$ tar xvf archive.tar file1.gz file2.gz file3.gz lab46:~/closet/thelab$ ls archive.tar file1.gz file2.gz file3.gz lab46:~/closet/thelab$ gzip -d file1.gz file2.gz file3.gz lab46:~/closet/thelab$ ls archive.tar file1 file2 file3 lab46:~/closet/thelab$ cat file1 This is file 1 lab46:~/closet/thelab$ cat file2 This is not file 1 or file 3 lab46:~/closet/thelab$ cat file3 file 3 this is.
Based on the data collected:
It does not matter which order you do archiving and compression, you will eventually end up with the same files you had before. The archive before compression method we use however is just a lot easier and I now understand why we don't compress first.
Today we went over the numeric based For loop and we spent all class on it. Here's an example that I've somewhat broken down:
for((i=0;i<6;i++));do
Here is a sample script we created:
echo -n "Enter a number: " read number echo -n "How many times: " read times for((i=$number;i=$times;i++));do let x=i*i echo "[$i] $x" done
We then were introduced to a few new commands such as cut, sort, and uniq.
We then went over the list based for loop or in other words, a loop that is typed out as a command/incantation
id username for user in echo -n "[$user]" id $user
This day I thought it was Monday so I wasn't actually around for the lecture, but here's what someone else learned.
mkdir -p
lab46:~/closet$ mkdir -p parent/child/seamen lab46:~/closet$ ls a_used_napkin login parent ricky seplogin cabinet loosemoose parentchildseamen script2 skeleton cake math pirate_swag script3 thelab lab46:~/closet$ cd parent lab46:~/closet/parent$ ls child lab46:~/closet/parent$ cd child lab46:~/closet/parent/child$ ls seamen
There was also a script that was created.. I'll just put that down here and interpret it later. The ^ is a reg function
#!/bin/bash # name ="`cat ${0}.conf|grep '^name='|cut -d '=' -f2 2>/dev/null`" if [-z "${name}"]; then echo -n "Who are you?" read name echo "Pleased to meet you $name" echo "name=$name">${0}.conf else echo "Welcome back, ${name}" fi
exit1: exit/return value as false exit0: exit/return value
On this day, we discussed Programming Paradigms and several types. Here's a bunch,
Lisp - great for lists
Prolog and Huskel, focuses on as or and nots
On this October day, we discussed a few common debugging strategies in reference to puzzlebox2, I have created a complete Puzzlebox2 guide way down below that entails much of the debugging strategies. We also discussed..
There is no clear definition for I/O redirection but both of these in the UNIX universe in particular are actually two components of our interface that we use at every given moment while actively using the terminal or even this browser. The Input is coming from your computer's keyboard or terminal keyboard while the Output is what you see on the monitor typically, such as in the Lab46 Terminal, the text you see is the output. In the middle of both input and output is actually where all the processing happens, this is key to the redirection as it has an effect to where the output will be directed. There are two kinds of I/O redirection, them being represented by the less than and greater than symbols ><. The less than < symbol is what does input redirection, commonly useful for when a program doesn't read files but reads from standard input, for example, you can have file1 send its contents to a mail of some sort like jackrabbit@rabies.org and the command would look something like this: mail jackrabbit@rabies.org < file1
The greater than > symbol does the “opposite” and is used in a different scenario. Say you wanted all the output you receive from issueing an ls -l command to be put into file2. Just do ls > file2 and all that output will be within the file.
Some other important concepts about I/O redirection is usage of the pipe | and the semicolon ;. The pipe and semi are used when you want to use more than one command at one time, but the difference between the two is crucial to a successful incantation. The pipe will redirect output from the initial command into the next command while the semicolon will not redirect any output into the next command, it will just perform it as if you were doing it singularly. A situation where the semicolon is crucial is if you have a cat command following your initial casting.
Now when you use the output redirect, one thing to keep in mind is that if you send another piece of output into file2 with a single >, it will overwrite the file with that new output and the old output from ls -l will no longer be there.
processes
Processes- programs or instances that operate concurrently with one another to produce a result.
List any sites, books, or sources utilized when researching information on this topic. (Remove any filler text).
Demonstration of the indicated keyword.
If you wish to aid your definition with a code sample, you can do so by using a wiki code block, an example follows:
/* * Sample code block */ #include <stdio.h> int main() { return(0); }
Alternatively (or additionally), if you want to demonstrate something on the command-line, you can do so as follows:
lab46:~$ cd src lab46:~/src$ gcc -o hello hello.c lab46:~/src$ ./hello Hello, World! lab46:~/src$
Can you create an incantation that is capable of make a directory, change into directory, creating two files, creating input to output into said files, rename them, change out of directory, archive it, and then compress it AND THEN decompress and extract them and cat them both as a sign of completion. And if this works, to make this better, make the incantation an application/program.
In class lectures and the O'Reilly Unix book.
The incantation itself may be correct and will execute but I feel like a runtime error is possible. Possible problems could be when creating the two files and redirecting output into them and where compression and decompress will happen, as they are back to back.
First, I'm going to do everything the normal way, normal as in typing each step out in seperate commands to get a feel for how it will look and ensuring I can assume file names when I tar and gzip. After doing that, I'll create the incantation itself and if it runs correctly, I will adjust it to be outputted into a file named “MobileCommandCenter” that will be the executable of this incantation, then I'll try running it in my practice area, then I'll move MobileCommandCenter into a seperate practice directory and do it again for consistency.
lab46:~/closet/thelab/Experiment2/Practice2$ mkdir directory ; cd directory ; touch file1 file2 ; ls -l /home/$USER > file1 ; ls / > file2 ; mv file1 listhome ; mv file2 listroot ; cd .. ; tar cf directory.tar directory ; gzip directory.tar ; rm -rf directory ; gzip -d directory.tar.gz ; tar xf directory.tar ; cd directory ; cat listhome listroot > completion
Discovered the difference between the | and the ;. Where the | expects output and applies it to the next command, the semicolon ; just does the command on the left and simply moves onto the next without the output carrying over.
lab46:~/closet/thelab/Experiment2/Practice2/directory$ echo 'echo `mkdir directory ; cd directory ; touch file1 file2 ; ls -l /home/$USER > file1 ; ls / > file2 ; mv file1 listhome ; mv file2 listroot ; cd .. ; tar cf directory.tar directory ; gzip directory.tar ; rm -rf directory ; gzip -d directory.tar.gz ; tar xf directory.tar ; cd directory ; cat listhome listroot > completion`' > MobileCommandCenter
lab46:~/closet/thelab/Experiment2$ ./MobileCommandCenter lab46:~/closet/thelab/Experiment2$ ls MobileCommandCenter directory directory.tar lab46:~/closet/thelab/Experiment2$ cd directory lab46:~/closet/thelab/Experiment2/directory$ ls completion listhome listroot lab46:~/closet/thelab/Experiment2/directory$ cat completion total 4 drwxr-xr-x 2 escoute1 lab46 6 Sep 5 14:50 Desktop drwxr-xr-x 2 escoute1 lab46 6 Sep 5 14:50 Documents drwxr-xr-x 2 escoute1 lab46 21 Sep 5 15:07 Downloads lrwxrwxrwx 1 escoute1 lab46 18 Sep 2 12:17 Maildir -> /var/mail/escoute1 drwxr-xr-x 2 escoute1 lab46 6 Sep 5 14:50 Music drwxr-xr-x 2 escoute1 lab46 6 Sep 5 14:50 Pictures drwxr-xr-x 2 escoute1 lab46 6 Sep 5 14:50 Public drwxr-xr-x 2 escoute1 lab46 6 Sep 5 14:50 Templates drwxr-xr-x 2 escoute1 lab46 6 Sep 5 14:50 Videos drwxr-x--x 3 escoute1 lab46 79 Sep 21 14:32 archives drwxr--r-- 4 escoute1 lab46 4096 Oct 3 16:21 closet lrwxrwxrwx 1 escoute1 lab46 28 Sep 7 11:25 data -> /usr/local/etc/data/escoute1 drwxr-x--- 3 escoute1 lab46 38 Oct 3 13:39 naming drwx-----x 2 escoute1 lab46 6 Aug 26 2009 public_html drwx------ 6 escoute1 lab46 84 Sep 28 16:52 src bin boot dev etc home initrd.img lib lib32 lib64 lost+found media mnt opt proc root sbin selinux srv sys tmp usr var vmlinuz
Based on the data collected:
As long as you can supply the semicolon and pipe properly, you can make your incantations as long as you please, in theory!
First we started with a file dubbed minecraft.jar but do not be fooled, this is not what it seems! NO MINECRAFT FOR YOU!
Anyway so we check to see what file type this really is using the file command and are returned with information regarding the file.
lab46:~/closet/thelab/puzzlebox2/Opus$ file minecraft.jar minecraft.jar: 7-zip archive data, version 0.3
As you can see, it tells us of a 7-zip archive file so that must mean that this file is expected to have a .7z file extension in order to be operated upon correctly. So we use the mv command to rename the minecraft.jar file to minecraft.7z and use ls to double check that it is indeed what we want.
lab46:~/closet/thelab/puzzlebox2/Opus$ mv minecraft.jar minecraft.7z lab46:~/closet/thelab/puzzlebox2/Opus$ ls minecraft.7z
Now we need to get the content out of this 7zip archive using the 7za command with the e option.
lab46:~/closet/thelab/puzzlebox2/Opus$ 7za e minecraft.7z 7-Zip (A) 9.04 beta Copyright (c) 1999-2009 Igor Pavlov 2009-05-30 p7zip Version 9.04 (locale=en_US,Utf16=on,HugeFiles=on,2 CPUs) Processing archive: minecraft.7z Extracting ls -l/result Extracting ls -l Everything is Ok Folders: 1 Files: 1 Size: 878 Compressed: 765 lab46:~/closet/thelab/puzzlebox2/Opus$ ls ls -l minecraft.7z result
As you can see, we now have a directory known as ls -l and a result file. The directory has nothing in it, perhaps some sort of hint, I dont even know but the main show is in the return file. Lets cat this file.
lab46:~/closet/thelab/puzzlebox2/Opus$ cat result #!/bin/b@ntehuiOUXUXUX@ash # # result - s@OUEUEIPYEDEYP@cript to finish up the task # echo -n "[p@OEUIDYPYDD@uzzlebox] " if [ -x "${0@DPY445dyp.pd@}" ]; then echo -n @EUEOUEDUIDUIDIUED@"1 " if [ -L @EIDUIDIUDUIEDUID@"${0}" ] && [ "${0#**/}" = "solution" ]; then echo@UIDUIDIUDUIDUIEDUI@ -n "2 " if [@%>PI$F%DYP$F%DYPF$%@ "`tail -1 ${0} | grep \"^#${USER}:.*$\" | wc -l`" -eq 1 ]; then @EUIOUIPD>YDYPH%@echo -n "YES, here is your token: " @IDD6d64464665hyph@md5sum "${0}" | cut -d' ' -f1 else@uideuydtnhiud@ @uidiuedud@echo "Very close." @iudiudiudiudui@exit 1 fi@uiduiduidiud@ else@uiduiduiduidiu@ echo@thndhtndthnth@ "Closer." exit@ngyncnycgcgcg@ 1 fi@dhni887ngccg@ else@gf8y778utguddu@ echo "No@uidhu7h6hf@t yet." exit 1@h7pp6h6h6h7@ fi@fhy890idu908@ exit 0@iuedidiuduid@ #username:@crg56rdhinthntiu@Fill out the previous field as appropriate
Holy craziness batman! Look at all that junk, what's a pattern however? Notice the @ signs and that in every instance of the @ sign, we have a bunch of junk. So we want to just remove all of the content inside these @ signs and the signs themselves in vi. result should now look like this when cated, I'm displaying it in script as it is going to be a script file of sorts.
#!/bin/bash # # result - script to finish up the task # echo -n "[puzzlebox] " if [ -x "${0}" ]; then echo -n "1 " if [ -L "${0}" ] && [ "${0#**/}" = "solution" ]; then echo -n "2 " if [ "`tail -1 ${0} | grep \"^#${USER}:.*$\" | wc -l`" -eq 1 ]; then echo -n "YES, here is your token: " md5sum "${0}" | cut -d' ' -f1 else echo "Very close." exit 1 fi else echo "Closer." exit 1 fi else echo "Not yet." exit 1 fi exit 0 #username:Fill out the previous field as appropriate
As you can see, we can easily recognize this as a script of some sort, waiting to be executed. But the file is a “normal readable file”, what do we do? Let's do the chmod command followed with 744 result to activate Owner's Executable with Read and Write, while Groups and World remain at Read. Now that our result file is now executable, we now run it with ./result (assuming you are in the directory it is in.
lab46:~/closet/thelab/puzzlebox2/Opus$ chmod 744 result lab46:~/closet/thelab/puzzlebox2/Opus$ ls ls -l minecraft.7z result lab46:~/closet/thelab/puzzlebox2/Opus$ ./result [puzzlebox] 1 Closer.
Our new result script seems to stop at our second if statement, let's disect what might be the cause of the intrusion, as we definately assume we have not reached our end with this puzzlebox. I pose the first question that you should wonder right away: What does the ${0} stand for? What does it mean? Well, take note that the $ indicates it is a variable. To what value or string is it? How do we find this out you may ask? Why not, echo our variables to see what they hide! Be sure to enter them before any if statement in order to prevent some issues. Of course, we edit in vi. ALSO notice that there are two variables.
lab46:~/closet/thelab/puzzlebox2/Opus$ vi result lab46:~/closet/thelab/puzzlebox2/Opus$ cat result #!/bin/bash # # result - script to finish up the task # echo -n "[puzzlebox] " echo -n "${0} " echo -n "${0#**/} " if [ -x "${0}" ]; then echo -n "1 " if [ -L "${0}" ] && [ "${0#**/}" = "solution" ]; then echo -n "2 " if [ "`tail -1 ${0} | grep \"^#${USER}:.*$\" | wc -l`" -eq 1 ]; then echo -n "YES, here is your token: " md5sum "${0}" | cut -d' ' -f1 else echo "Very close." exit 1 fi else echo "Closer." exit 1 fi else echo "Not yet." exit 1 fi exit 0 #username:Fill out the previous field as appropriate
And we run result once again..
lab46:~/closet/thelab/puzzlebox2/Opus$ ./result [puzzlebox] ./result result 1 Closer.
Ah now that is interesting! We have been returned a (dot)/result and a result for our output along with the resulting if statement's output. That must mean that our variable {0} is the executable version of result, whilst our other variable is the file itself.
Now lets look at where we are getting our 1 Closer. Here's a better view of what if statement we are speaking of.
if [ -L "${0}" ] && [ "${0#**/}" = "solution" ]; then echo -n "2 "
Assuming you've done some research on the [ using the man, we would recognize the -L as a symbolic link. So the first part is a symbolic link of the executable result. The && indicates an AND operator, indicating this symbolic link is to fulfill both the executable and the file itself based on the second variable, and then we see an = “solution”, meaning it is looking for a symbolic link that is named solution that points to the result data file. With all that in mind, what do you think we should do? CREATE a symbolic link! (AYUAYAYAHAY!) We do this using ln -s [TARGET FILE] [SYMBOLIC LINK NAME] then we shall run our new symbolic link solution
lab46:~/closet/thelab/puzzlebox2/Opus$ ln -s result solution lab46:~/closet/thelab/puzzlebox2/Opus$ ls ls -l minecraft.7z result solution lab46:~/closet/thelab/puzzlebox2/Opus$ ./solution [puzzlebox] ./solution solution 1 2 Very close.
NOTICE that our variable's values have changed in this instance? The symbolic link simply replaces the return name in all instances when ran from the symbolic link solution, so any variable that means to point at result is pointing at solution (or what I'd call, pseudo-result).
Lets move onto our next and last if statement to our final prize!
if [ "`tail -1 ${0} | grep \"^#${USER}:.*$\" | wc -l`" -eq 1 ]; then echo -n "YES, here is your token: " md5sum "${0}" | cut -d' ' -f1
The only part of this if statement we need to focus on is what tail -1 means. What does it indicate? It indicates or points to the end of the file result(or solution). So why don't we look at the end?
#username:Fill out the previous field as appropriate
Seems meaningless, but read what it says. We need to fill out the field(placeholder username) with our username, more specifically whatever username is connected to your personalized $USER, we figure this from the if statement itself where it greps for the $USER. So for this scenario, let's use jackrabbits as the username, just remember to use YOUR username or whatever is logged in when running this program.
#jackrabbits:Fill out the previous field as appropriate
Now that we filled that out, lets run our symbolic link solution.
lab46:~/closet/thelab/puzzlebox2/Opus$ ./solution [puzzlebox] 1 2 YES, here is your token: 0a9563f07993a814e860c2c616db0413
Viola! The puzzlebox is solved! Congrats! I helped you cheat!
This is a sample format for a dated entry. Please substitute the actual date for “Month Day, Year”, and duplicate the level 4 heading to make additional entries.
As an aid, feel free to use the following questions to help you generate content for your entries:
Remember that 4 is just the minimum number of entries. Feel free to have more.
This is a sample format for a dated entry. Please substitute the actual date for “Month Day, Year”, and duplicate the level 4 heading to make additional entries.
As an aid, feel free to use the following questions to help you generate content for your entries:
Remember that 4 is just the minimum number of entries. Feel free to have more.
This is a sample format for a dated entry. Please substitute the actual date for “Month Day, Year”, and duplicate the level 4 heading to make additional entries.
As an aid, feel free to use the following questions to help you generate content for your entries:
Remember that 4 is just the minimum number of entries. Feel free to have more.
This is a sample format for a dated entry. Please substitute the actual date for “Month Day, Year”, and duplicate the level 4 heading to make additional entries.
As an aid, feel free to use the following questions to help you generate content for your entries:
Remember that 4 is just the minimum number of entries. Feel free to have more.
Let's talk.
talk is a program that provides visual communication between two parties via text through the terminal. ( talk person ) Using this command alone will prompt the second party with the following message:
At this point, the terminal will be now a chat window between the two parties. Both parties can type at the same time since their text appears in different parts of the window. To exit the window, use CTRL + C
ytalk is a program that provides visual communication between multiple parties via text through the terminal. It's basically the same program as talk, only it allows for multiple connections. ( ytalk [-s] [-Y] [-E] [-i] [-q] [-v] [-h hostname_or_ip] username… )
The username portion can be formatted in the following ways:
You can also specify multiple usernames on the command line with ytalk ( ytalk george fred@hissun.edu marc@grumpy.cc )
Say hello to the options:
More to be added with more awesome details to come.
Tail
The tail command allows you to grab the last line(s) from the output of a previous command or from a file. Unless you specify the number of lines that you would like the command to grab, it will default to return the last ten lines. In order to specify the the number of lines, add -# (# being the actual number if lines you want to grab) to the command.
List any sites, books, or sources utilized when researching information on this topic. (Remove any filler text).
Demonstration of the indicated keyword.
If you wish to aid your definition with a code sample, you can do so by using a wiki code block, an example follows:
/* * Sample code block */ #include <stdio.h> int main() { return(0); }
Alternatively (or additionally), if you want to demonstrate something on the command-line, you can do so as follows:
lab46:~$ cd src lab46:~/src$ gcc -o hello hello.c lab46:~/src$ ./hello Hello, World! lab46:~/src$
What is the question you'd like to pose for experimentation? State it here.
Collect information and resources (such as URLs of web resources), and comment on knowledge obtained that you think will provide useful background information to aid in performing the experiment.
Based on what you've read with respect to your original posed question, what do you think will be the result of your experiment (ie an educated guess based on the facts known). This is done before actually performing the experiment.
State your rationale.
How are you going to test your hypothesis? What is the structure of your experiment?
Perform your experiment, and collect/document the results here.
Based on the data collected:
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.