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~~TOC~~
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//
//
<WRAP centeralign 90% bigger>
<WRAP bigger fgred>A Record of Sorts</WRAP>
<WRAP muchbigger>Ctrl-Alt-wink-wink</WRAP>
... one man's trip down the rabbit hole.
</WRAP>
<WRAP left 50%>
<WRAP info left 80% bgwhite>
You have stumbled upon Matt Cooper's web log.  This page is organized in a manner that makes it easy to stroll through many technical topics of one sort or another, mostly gathered throughout Matt's journey through the universe of computer science and information security.  Don't look for topics to bubble up to the top.  That's not how this works.  This is more of a wiki-log.  Use the navigation to the left, or visit [[documentation:linkgarden|The Lab46 Link Garden]] (highly recommended).
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=====Hi, I'm Matt=====
<WRAP centeralign 100% fgred>
Drawing on my fine command of language, I said nothing.
<WRAP rightalign 75%>- Mark Twain</WRAP>
</WRAP>

Hi, I'm Matt, small business owner, husband, father and lately, student of computer science.  I read somewhere that a computer is to computer science as the telescope is to astronomy, and I agree.

<WRAP info box bgwhite>
Here are some interesting things (you decide) about me:
  *I don't laugh at bad jokes, but dry humor is damned funny.  Like this little comic: [[http://xkcd.com/325/| Box contained bobcat]]
  *I yell at politicians on TV. (Everyone has to have that one crazy thing, this is mine.)
  *I should probably relax.
  *I referee NCAA soccer games. Yep, for fun!
  *My Lab46 Web Home is [[http://lab46.corning-cc.edu/~mcooper6/|here]].
</WRAP>
In my professional life I develop web applications and business systems for small businesses.  ([[http://www.mypluribus.com|MyPluribus.com]]).  Running a business can be pretty difficult, so I work daily to help small business owners learn to use technology to solve their problems.  I spend lots of time reading help files, writing help files and creating widgets and systems that accomplish a variety of goals.


The other side of my life revolves around my family.  I have a beautiful wife and a very bright young son.  My wife is a great wife and mother.  My son is a great kid.  When I'm not working, I'm with them.  This is my idea of a really good life.
=====Chemistry=====
A hastily-thrown-together group of information that may help you memorize some things (as it did me):
  *[[chemistry|Chemistry Resources]]
=====Computer Organization=====
  *[[m6800|m6800 Simulator (Wiki)]]
  *[[http://lab46.corning-cc.edu/~mcooper6/m6800/|m6800 Simulator (Sim)]]
=====C Programming=====
====Dealing Cards====
In the game Freecell, cards are dealt into columns.  Later, interactions take place with the cards that makes the game fun to play ... however, more interesting to me is the logic of dealing out the cards.

This first snippet deals out the tableus (that is the columns) by dealing 1 card per column for 8 columns until all 52 cards have been dealt.  This snippet uses an arbitrary check to see if the number of cards dealt has reached 52.  (Not all that complex, however it takes care of the deal pattern.)
<code>

#include <stdio.h>
#include <stdlib.h>

int main(){

        int ctDeal=0;

        int deal[8][52];

        int row, col;

// deal the cards

        for(row = 0; row < 52; row++){

                for(col = 0; col < 8; col++){
                
                        deal[col][row] = ctDeal;
                        ctDeal++;

                        if(ctDeal > 52){
                                col = 8;
                                row = 52;
                        }
                }

        }

// show the deal

        ctDeal = 0;

        for(row = 0; row < 52; row++){

                for(col = 0; col < 8; col++){

                        printf("| %d |", deal[col][row]);
                        ctDeal++;

                        if(ctDeal > 52){
                                row = 52;
                                col = 8;
                        }
                }
                printf("\n");
        }

}

</code>

Next, a short snippet that takes care of some random numbering and dealing out 13 cards from each suit:

<code>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>

int main(){

        int ctSpades = 0;
        int ctClubs = 0;
        int ctHearts = 0;
        int ctDiamonds = 0;
        int ctDeal = 0;

        srand(time(NULL));

        printf("time is %d \n", time(NULL));

        int num, num2, row, col;

        row = 0;
        col = 0;

        while(ctDeal < 52){

                num = rand() % 4+1;

                switch(num){

                        case 1:

                                if(ctClubs < 13){
                                        printf("case is Clubs ctClubs = %d -- ctDeal = %d \n", ctClubs, ctDeal);
                                        ctClubs++;
                                        ctDeal++;
                                }
                                break;

                        case 2:

                                if(ctSpades < 13){
                                        printf("case is Spades ctSpades = %d -- ctDeal = %d \n", ctSpades, ctDeal);
                                        ctSpades++;
                                        ctDeal++;
                                }

                                break;

                        case 3:

                                if(ctHearts < 13){
                                        printf("case is Hearts ctHearts = %d -- ctDeal = %d \n", ctHearts, ctDeal);
                                        ctHearts++;
                                        ctDeal++;
                                }
                                break;

                        case 4:

                                if(ctDiamonds < 13){
                                        printf("case is Diamonds ctDiamonds = %d -- ctDeal = %d \n", ctDiamonds, ctDeal);
                                        ctDiamonds++;
                                        ctDeal++;
                                }
                                break;

                }


        }
}

</code>

The process is as follows: Fist, generate a random number between 1 and 4 (I.E. the number of suits in a deck of cards); next, a switch statement is hinged upon this random number and a counter for each suit is incremented.  If the suit's counter reaches 12 then that suit is empty (that is, it has been dealt out) and a random number is redrawn.  However, note that this script outputs the cards in a highly predicable manner.  more to come.


=====Data Structures=====
  *[[http://lab46.corning-cc.edu/documentation/data|Data Structures (observations)]]

====Linked List Insert====

The linked list is a fairly complex idea that consists of a series of simple ideas.  The general idea is to implement a system whereby each element has a reference to the next and/or previous elements in a list.  The list could be ordered or unordered.  The important part is that the list knows the end of one element and/or the beginning of the beginning of the next.

<code>
/*
 * linkedlist4.c - singly linked list node insertion
 *
 */
#include <stdio.h>
#include <stdlib.h>

// The node
struct node {
        int value;
        struct node *next;
};
typedef struct node Node;

int main()
{
        Node *start, *tmp, *devnull;

        int i = 0, input = 0;

        start = tmp = NULL;

        do {
                printf("Enter a value (-1 to quit): ");
                scanf("%d", &input);

                if ((start == NULL) && (input != -1))
                {
                        start = (Node *) malloc (sizeof(Node));
                        tmp = start;
                        tmp -> value = input;
                        tmp -> next = NULL;
                }
                else if (input != -1)
                {
                        tmp -> next = (Node *) malloc (sizeof(Node));
                        tmp = tmp -> next;
                        tmp -> value = input;
                        tmp -> next = NULL;
                }
        } while (input != -1);

        tmp = start;

        printf("Linked List DISPLAY: ");
while (tmp != NULL)
	{
		printf ("(%d) %d -> ", i, tmp -> value);
		tmp = tmp -> next;
		i++;
	}
	printf ("NULL\n");

	tmp = start;
	printf("Select Node # to insert before: ");
	scanf("%d", &input);

	for (i = 0; i < (input - 1); i++)
	{
		tmp = tmp -> next;
	}

	if ((i == 0) && (input == 1))
	{
		i++;
	}

	printf("Enter value for new node: ");
	scanf("%d", &input);

	// Create new node
	devnull = (Node *) malloc (sizeof(Node));
	devnull -> value = input;

	if (i != 0)	// anything but the first
	{
		devnull -> next = tmp -> next;
		tmp -> next = devnull;
	}
	else	// the first node
	{
		devnull -> next = start;
		start = devnull;
	}

	tmp = start;
	i = 0;

	printf("Linked List DISPLAY: ");
	while (tmp != NULL)
	{
		printf ("(%d) %d -> ", i, tmp -> value);
		tmp = tmp -> next;
		i++;
	}
	printf ("NULL\n");

	return(0);
}
</code>

====Linked List Delete====
<code>
/*
 * linkedlist3.c - singly linked list node deletion
 *
 */
#include <stdio.h>
#include <stdlib.h>

// The node
struct node {
	int value;
	struct node *next;
};
typedef struct node Node;

int main()
{
	Node *start, *tmp, *devnull;

	int i = 0, input = 0;

	start = tmp = NULL;

	do {
		printf("Enter a value (-1 to quit): ");
		scanf("%d", &input);

		if ((start == NULL) && (input != -1))
		{
			start = (Node *) malloc (sizeof(Node));
			tmp = start;
			tmp -> value = input;
			tmp -> next = NULL;
		}
		else if (input != -1)
		{
			tmp -> next = (Node *) malloc (sizeof(Node));
			tmp = tmp -> next;
			tmp -> value = input;
			tmp -> next = NULL;
		}
	} while (input != -1);

	tmp = start;

	printf("Linked List DISPLAY: ");
	while (tmp != NULL)
	{
		printf ("(%d) %d -> ", i, tmp -> value);
		tmp = tmp -> next;
		i++;
	}
	printf ("NULL\n");

	tmp = start;
	printf("Select Node # to delete: ");
	scanf("%d", &input);

	for (i = 0; i < (input - 1); i++)
	{
		tmp = tmp -> next;
	}

	if (i != 0)	// anything but the first
	{
		devnull = tmp -> next;
		tmp -> next = devnull -> next;
	}
	else	// the first node
	{
		devnull = start;
		start = devnull -> next;
	}
	devnull -> next = NULL;
	free(devnull);

	tmp = start;
	i = 0;

	printf("Linked List DISPLAY: ");
	while (tmp != NULL)
	{
		printf ("(%d) %d -> ", i, tmp -> value);
		tmp = tmp -> next;
		i++;
	}
	printf ("NULL\n");

	return(0);
}
</code>
=====Dell Latitude D531 Wifi=====
  *[[http://lab46.corning-cc.edu/user/mcooper6/dell_latitude_d531_wifi|Dell Latitude D531 Wifi]]
=====Mac=====
  *[[http://lab46.corning-cc.edu/user/mcooper6/rescue_mac|Rescue data from a Mac that won't boot]]

=====Mathy Stuff=====
====The Lab46 Math Pages====
  *[[http://lab46.corning-cc.edu/math/start|Lab46 Math Pages]]
  *[[http://lab46.corning-cc.edu/math/3x3numbersystems|3x3 Number Systems]]
  *[[http://lab46.corning-cc.edu/math/specialproducts|Special Products in Algebra]]
====LaTeX on the Lab46 Wiki====

I asked for, and was awarded with the DokuWiki LaTeX plugin, with hopes that I would be able to find some extra time to explore some mathematic markup and ultimately find a digital den for my math notes.  Before I could start, I needed to take a short side-trip through the LaTeX documentation.

Here's an example of a matrix:

<code>
<latex>
    D_z
    = \left|
    \begin{array}{ccc}
    y_1 ... C_1\\
    \vdots \ddots \vdots\\
    y_2 ... C_2\end{array}
    \right| -> z = \frac{D_z}{D} => y = \frac{(-4)(-55)-(14)(0)}{(-4)(-12)-(14)(5)} => z = -10
</latex>
</code>

This is the output of the above LaTex:

<latex>
D_z
= \left|
\begin{array}{ccc}
y_1 ... C_1\\
\vdots \ddots \vdots\\
y_2 ... C_2\end{array}
\right| -> z = \frac{D_z}{D} => y = \frac{(-4)(-55)-(14)(0)}{(-4)(-12)-(14)(5)} => z = -10
</latex>

Here's another one showing some simple math layouts

<code>
<latex>
    \begin{array}{3}
    -5(3x - 3y + 2z = 11)\\
    \underline{+ 15x -   y  - 2z =  0}\\
    14y - 12z = -55\\
    .\end{array}\\
</latex>
</code>

This is the output of the above LaTeX

<latex>
\begin{array}{3}
-5(3x - 3y + 2z = 11)\\
\underline{+ 15x -   y  - 2z =  0}\\
14y - 12z = -55\\
.\end{array}\\
</latex>

As you can see, LaTeX isn't the easiest on the eyes.  In fact, it's a little ugly.  But it does something that can't be done easily on any platform, so you have to respect that.

===Useful Links===
  *[[http://www.tug.org/tutorials/latex2e/|A good LaTeX tutorial]]
  *[[http://www.maths.tcd.ie/~dwilkins/LaTeXPrimer/|Another good LaTeX tutorial]] 

=====Musings=====
<WRAP centeralign 100% fgred>
Diplomacy is the art of saying "Nice doggie" until you can find a rock.
<WRAP rightalign 75%>- Will Rogers</WRAP>
</WRAP>

====A Political Suggestion====

A Metaphor:

Since there are two groups:

  -Group 1 believes that every citizen is entitled to a chicken and a mule.
  -Group 2 believes that, since there are plenty of chickens and plenty of mules, then we should simply give each citizen the opportunity to earn their chicken and/or mule ... and therefore, if a citizen goes without a chicken and/or a mule, then they must not have wanted the chicken or the mule.

Further, since the laws of nature state that possession of said chickens and mules must, at some point, be earned.

Then, I suggest that the Group 1 get together and start earning chickens and mules, and then give them all away to the citizens that they believe are entitled to those chickens and mules.  I also suggest that those who belong to Group 2, each earn their own chickens and mules.
====A is for Curiosity====
Having been asked the question, 'What do you think your grade should be?' by more than one professor, I've cataloged my response here to save time in the future.  If you're one of said professors, please find my response below:

>Education is relative.  Education requires motivation.  Education shrugs off the disingenuous, and accepts only those who arrive without gimmick.  Education cannot be lured, rather it is a gift to those who find a thrill and sense of accomplishment in the pursuit.  Many seek an end to their education, others look for the newest beginning.  Yet, learning never stops, and therefore cultivation and innovation remain the accomplishments of the curious.  That is to say, the journey is the prize.

=====Java Programming=====
  *[[/documentation/javanetworklaunchprotocol|Java Network Launch Protocol: Up and Running]]
=====PHP Programming=====
  *[[http://lab46.corning-cc.edu/~mcooper6/pi/|1 Million Bits of Pi]]

The objective of the project is simply an exercise in learning a new (to me) programming language using a simple data set.  The following .PHP file reads in a local (to Lab46) file containing a single line which holds the first million digits of pi.  The line is split into pages of 100 groups of 64 digits (that is, 6400 digits per page).  A pagination script breaks down simple links to nearby pages, allowing the user to investigate all 1 million digits.  Enjoy:

<code php>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Frameset//EN">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=MacRoman">
<title>1 Million Bits of Pi</title>

<link rel="stylesheet" type="text/css" href="pi.css">
</head>
<body>
<?php
 	$max_rows = 100; // maximum rows of output
	$chunk = 64; // size of data chunk
	$nearby = 21; // number of nearby pages
/*
 *  number of chars per page  == 
 *  	($max_rows * $chunk * $page_num > ftell(END) ? ftell(END) - ($max_rows * $chunk * $page_num) : $max_rows * $chunk)
 *
 *  number of pages == ftell(END) / ( $max_rows * $chunk )
 *  starting digit of page == $page_num * $max_rows * $chunk
 *
 *  end digit of page == 
 *	 ($max_rows * $chunk * $page_num + $max_rows * $chunk > ftell(END) ? 
 * 	$max_rows * $chunk * $page_num) + ftell(END) - ($max_rows * $chunk * $page_num)
 *	:$max_rows * $chunk * $page_num + $max_rows * $chunk);
 */

	$i = 0; // iterator
	$odd = 0; // number of odd digits per line
	$max_odd = 0;
	$even = 0;
	$max_even = 0;
	$sum = 0;
	$max_sum = 0;
	$primes = 0;

	$zeros = 0;
	$ones = 0;
	$twos = 0;
	$threes = 0;
	$fours = 0;
	$fives = 0;
	$sixes = 0;
	$sevens = 0;
	$eights = 0;
	$nines = 0;

	$file_name = "pi.txt";
	$f = fopen($file_name, "rb");
//ECHO TITLE
	echo "<div id=\"title\">1 Million Bits of Pi</div>";

// BEGIN PAGINATION (minimal use of variables)

	$p = (int)$_GET['p']; //page sought
	echo "<div id=\"pagination\">";

	// go to the place sought
	fseek($f, $chunk*$max_rows*$p);
	echo ($p > 1 ? "<div class=\"start\"><a href=\"?p=0\">Start</a></div>" : "");
	echo ($p > 0 ? "<div class=\"prev\"><a href=\"?p=" . ($p-1) . "\">Previous</a></div>" : "");

	// loop nearby previous page lines
	$n = ($p < 1 ? 0 : ($p < $nearby ? 0 : $p-$nearby ));
	$limit = $p;
	for($n; $n < $limit; $n++){
		echo "<span class=\"link\"><a href=\"?p=" . $n . "\">" . $n . "</a></span>";
	}	
	echo "<div class=\"page\">Page : " . $p . "</div>";

	// go to end
	fseek($f, -$chunk*$max_rows, SEEK_END);

	// loop nearby next page lines
	$n = $p+1;
	$limit = ($p+$nearby < round(ftell($f)/($chunk*$max_rows)+0.5) ? $p + $nearby: round(ftell($f)/($chunk*$max_rows) + 0.5));
	for($n; $n <= $limit; $n++){
		echo "<span class=\"link\"><a href=\"?p=" . $n . "\">" . $n . "</a></span>";
	}	
	echo ($p < ftell($f)/($chunk*$max_rows) ? "<div class=\"next\"><a href=\"?p=" . ($p+1) . "\">Next</a></div>" : "");
	echo ($p != round(ftell($f)/($chunk*$max_rows)+0.5) ? "<div class=\"end\"><a href=\"?p=" . round(ftell($f)/($chunk*$max_rows) + 0.5) . "\">End</a></div>":"");

// back to the place sought
	fseek($f, $chunk*$max_rows*$p);
	echo "</div>";

// END PAGINATION

	echo "<table>";
	echo "<colgroup class=\"i\"></colgroup>";
	echo "<colgroup class=\"pi\"></colgroup>";
	echo "<colgroup class=\"even\"></colgroup>";
	echo "<colgroup class=\"odd\"></colgroup>";
	echo "<colgroup class=\"primes\"></colgroup>";
	echo "<colgroup class=\"sum\"></colgroup>";

	echo "<colgroup class=\"zeros\"></colgroup>";
	echo "<colgroup class=\"ones\"></colgroup>";
	echo "<colgroup class=\"twos\"></colgroup>";
	echo "<colgroup class=\"threes\"></colgroup>";
	echo "<colgroup class=\"fours\"></colgroup>";
	echo "<colgroup class=\"fives\"></colgroup>";
	echo "<colgroup class=\"sixes\"></colgroup>";
	echo "<colgroup class=\"sevens\"></colgroup>";
	echo "<colgroup class=\"eights\"></colgroup>";
	echo "<colgroup class=\"nines\"></colgroup>";

	echo "<thead><tr>";
	echo "<th colspan=\"2\">";
	echo "<div class=\"showing\">Showing digits <strong>" . ftell($f) . "</strong> thru <strong>" . (ftell($f) + $chunk*$max_rows -1) . "</strong></div>";
	echo "</th><th colspan=\"2\"></th><th></th><th></th><th colspan=\"10\">Occurence of Each Digit</th>";
	echo "</tr><tr>";
	echo "<th>i</th><th>64 Bits of Pi</th><th>Even</th><th>Odd</th><th>Primes</th><th>Sum</th>";

	echo "<th>Zeros</th><th>Ones</th><th>Twos</th><th>Threes</th><th>Fours</th>";
	echo "<th>Fives</th><th>Sixes</th><th>Sevens</th><th>Eights</th><th>Nines</th>";

	echo "</tr></thead>";
	echo "<tbody>";
	$i = $p*$max_rows;
	while (!feof($f) && $i < ($p*$max_rows+$max_rows)) {
		$d = fread($f, $chunk);
		$a = str_split($d);
		foreach($a as $v){
			if($v % 2 == 0){
				$even++;
			}else{
				$odd++;
			}
			$sum += $v;

			switch($v){
				case 0:
					$zeros++;
					break;
				case 1:
					$ones++;
					$primes++;
					break;
				case 2:
					$twos++;
					break;
				case 3:
					$threes++;
					$primes++;
					break;
				case 4:
					$fours++;
					break;
				case 5:
					$fives++;
					$primes++;
					break;
				case 6:
					$sixes++;
					break;
				case 7:
					$sevens++;
					$primes++;
					break;
				case 8:
					$eights++;
					break;
				case 9:
					$nines++;
					break;
			}

		}
		echo "<tr>";
		echo "<td class=\"i\">" . $i . "</td>";
		echo "<td class=\"pi\">" . $d . "</td>";
		echo "<td class=\"even\">" . $even . "</td>";
		echo "<td class=\"odd\">" . $odd . "</td>";
		echo "<td class=\"primes\">" . $primes . "</td>";
		echo "<td class=\"sum\">" . $sum . "</td>";
		echo "<td class=\"zeros\">" . $zeros . "</td>";
		echo "<td class=\"ones\">" . $ones . "</td>";
		echo "<td class=\"twos\">" . $twos . "</td>";
		echo "<td class=\"threes\">" . $threes . "</td>";
		echo "<td class=\"fours\">" . $fours . "</td>";
		echo "<td class=\"fives\">" . $fives . "</td>";
		echo "<td class=\"sixes\">" . $sixes . "</td>";
		echo "<td class=\"sevens\">" . $sevens . "</td>";
		echo "<td class=\"eights\">" . $eights . "</td>";
		echo "<td class=\"nines\">" . $nines . "</td>";

		echo "</tr>";
		$odd = 0;
		$even = 0;
		$sum = 0;

		$zeros = 0;
		$ones = 0;
		$twos = 0;
		$threes = 0;
		$fours = 0;
		$fives = 0;
		$sixes = 0;
		$sevens = 0;
		$eights = 0;
		$nines = 0;
		$primes = 0;

		$i++;
	}
	echo "</tbody></table>";
	echo "<div id=\"footer\">PHP in Vi (<a href=\"http://lab46.corning-cc.edu/~mcooper6\">M</a>)</div>";
	fclose($f);
?>
</body>
</html>
</code>

=====References & Resources=====
  *[[/documentation/linkgarden|The Lab46 Link Garden]]
=====*NIX=====

====alias====
To get a list of all current alias's on the system:
<cli>
:~$ alias
</cli>

So, for example to make a change to your ls command, issue the following:
<cli>
:~$ alias ls='ls -color=auto -a'
</cli>
The previous command will cause ls to automatically show color and dot files.

Other useful alias commands:

Protect yourself from accidental overwrite when copying files: (-i for interactive)
<cli>
:~$ alias cp='cp -i'
</cli>

Do the same when moving files:
<cli>
:~$ alias mv='mv -i'
</cli>

And of course for removing files:
<cli>
:~$ alias rm='rm -i'
</cli>
====aptitude====
===Finding Packages===
Installing a package begins with aptitude search (that is, unless you already know the name).  So, for example, if you're looking for the MySQL package, use the following command:

<cli>
:~$ aptitude search mysql
</cli>

The above command returns a list of all packages containing the search phrase.  Regular **expreshnas** can be substituted for the search term.  Additionally, due to Debian's package manager, getting dependent packages happens automatically.

===Installing packages===

Installing packages requires the ''install'' option to be passed to the aptitude command...and since the average user doesn't have ROOT privilege, the sudo (super-user do) command is necessary.  For example:

<cli>
:~$ sudo aptitude install less

:~$ sudo aptitude install screen
</cli>
Other packages I've installed:
  *irssi
  *ngircd

The previous commands install the less and screen utilities. (which I installed during Linux class earlier this week.)

<WRAP info>
screen has many more uses than just running irssi.  For example, if you have a large file that you're downloading with wget, simply open a new screen session, start the download, detach the from the screen, go home, maybe make a snack, catch a little shut eye ... you're screen session will be plugging away, awaiting your return. 
</WRAP>
===Installing apache server===

I began by checking to see if Apache was already installed on vm34.student.lab.  In this case, it wasn't so I search for the latest package with the following command.

<cli>
:~$ aptitude search apache
</cli>

At the top of the list is Apache2 "Metapackage".  I chose that and installed it.

<cli>
:~$ sudo aptitude install apache
</cli>

After installing Apache, you can check the install using telnet.

<cli>
:~$ telnet localhost 80
</cli>

However, since telnet is not yet installed on vm34, issue the following command:
<cli>
:~$ aptitude install telnet
</cli>

Then have another go at the previous command.

===Uninstalling packages===

Uninstalling packages is only slightly different from installing:

<cli>
:~$ sudo aptitude remove nano
</cli>

The previous command uninstalls the nano editor. (not sure who ever needed this in the first place ... vi)

====Bash Scripting: Intro====
All you need to create a bash file is a text editor and a bash shell to run it.  Start by creating a file with no extension:

<cli>
:~$ nano ./home/$USER/basherific
</cli>

OR

<cli>
:~$ touch ./home/$USER/basherific
</cli>

OR

<cli>
:~$ vi ./home/$USER/basherific
</cli>

After you've created your file, open it with your favorite text editor and get ready to add your bash script.  Let's do something simple like create a variable and pass some arguments from the command line.

Begin by adding the following to your bash file:

<code bash>
#! /bin/bash

usr=`who | grep $USER`

echo $usr
</code>

This short script creates a variable (in this case, named ''who'') and assigns it the value of ''who | grep $USER''.  Notice the ''$USER''?  That's an environment variable that returns your user name.  Also note, those aren't single quotes, they're back quotes (A.K.A. ''back ticks'').  The next line echos the variable out to standard output.  Save your file when you're finished.
<WRAP info bgwhite>
What's ''#! /bin/bash'' ??  ... known as the sh-bang, this tells the interpreter what shell to use when executing the script.  Since the ''#'' symbol acts as a comment in the bash shell, programmers call this the ''sh'' ... as in "hush up compiler", and the exclamation point is known as the ''bang'' as in something exciting that just went down.  Further, had this been a Perl script this line would have read ''#! /bin/perl''  ... get it?
</WRAP>

Now simply change the file permissions and you can call your new bash script from the command line:

<cli>
:~$ chmod +x ./home/$USER/basherific

# ... $USER refers to your linux username.
</cli>

Now call it:

<cli>
:~$ ./home/$USER/basherific
</cli>

This example, while very simple, illustrates one of the many ways that users can use bash scripts to turn Linux into a multi-tasking machine.  But, what if we wanted to get a little more involved.  Wouldn't it be nice to call the script by file name, like you do any other utility.  You can.  Simply add the directory containing your script to your $PATH environment variable:

<cli>
:~$ PATH=$PATH:./home/$USER
</cli>

The dot above is very important. To make sure you got it right:

<cli>
:~$ echo $PATH
</cli>

You should see your updates at the end of the list.  Now, you can call your bash script by name, and bash will happily search through all the possible directories listed in $PATH until it finds your new utility.

<cli>
:~$ basherific
</cli>

Next, using the redirection operator ''>>'', send the output of this script to a file in the filesystem.  Add the following line to your bash script:
<cli>
echo $usr >> whoami.txt
</cli>
Save your file and run it.

<cli>
:~$ ./basherific
</cli>

Now ''cat'' the new file:

<cli>
:~$ cat ./whoami.txt
</cli>

The contents of your new file will be the results of your bash script.

Lets have one more test.  Let's have the bash script tell us if we were successful.  Add the following at the end of your bash script: 

<cli>
file ./whoami.txt && echo "Success" || echo "Fail"
</cli>

This is a programmer friendly way check to make sure that the script actually did what it was told to do.  However, as usual, there's another way.  Try this:

Comment out this line
<cli>
#file ./whoami.txt && echo "Success" || echo "Fail"
</cli>
Then add this:
<cli>
if [ -e ./whoami.txt ]; then
  echo "Success"
else
  echo "Fail"
fi
</cli>

Save and close your bash script.  Don't forget to remove your whoami.txt file, so it can be recreated:

<cli>
:~$ rm ./whoami.txt

:~$ ./basherific
</cli>

You should receive a message stating that your venture was a success.  Now, remove your file again and then comment out this line:

<cli>
#echo $usr >> whoami.txt
</cli>

Now, when the script is run, ''whoami.txt'' will not be created and the script returns "Fail".  There you have it, a simple, yet effective way to test different boolean conditions.

<WRAP info bgwhite>
The ''>''''>'' operator appends to the end of a file, while the ''>'' operator overwrites the contents of the file.  Be warned.
<cli>

##
## Append to a file
##

:~$ echo $usr >> whoami.txt

##
## Overwrite a file
##

:~$ echo $usr > whoami.txt

</cli>

</WRAP>
=== Useful Links ===
  * [[http://www.gnu.org/software/bash/manual/bashref.html|Bash Reference Manual]]
  * [[http://tldp.org/LDP/abs/html/|Advanced Bash-Scripting Guide]]
  * [[http://www.ibm.com/developerworks/library/l-bash.html|Bash by example, Part 1]]
  * [[http://www.ibm.com/developerworks/library/l-bash2.html|Bash by example, Part 2]]
  * [[http://ss64.com/bash/|An A-Z Index of the Bash command line for Linux.]]

====Bash Scripting: Practical Examples====
===Looping===
<code>

while read LINE ; do

     echo "$LINE"

done < fall2010-20100315.html

</code> 

The above lines simply tell bash to read in another line from the file, as long as there are more lines to read.  Once the file runs out of lines, the script is done.

In this case, the actual iterator is LINE, so we can output that by itself to get the actual line of text, however we can't count using this line as an iterator, and wouldn't it be handy to output some line numbers while coding the solution.  To do this, add another variable inside the body of the while loop.  This variable is incremented each time the loop executes.

<code>

while read LINE ; do

     N=$(($N+1))
     echo "$N : $LINE"

done < fall2010-20100315.html

</code> 

Now the code outputs line numbers, which might or might not come in handy.
 
===numtest===
  *Obtain 4 numbers from the user; in a variable called sum, store the sum of these 4 numbers. In a variable called product, store the product. Consider utilizing “bc” to assist you.

This script uses a ''for loop'' to gather some numbers from the user.  However, you'll notice that I didn't use ''bc'', in fact I didn't do any multiplication at all.  I'll be revisiting ''bc'' this in the coming days.
 
<file bash numtest>
#!/bin/bash

product=1
for((i=0;i< 4; i++)); do
        num=0
        echo -n "Enter number $i: "
        read num
        let sum=$sum+$num
        let product=$(($product*$num))
done

echo "sum is $sum"
echo "product is $product"
</file>

===nametest===
  *Prompts the user for their name, stores it in a variable, and outputs that name along with its length in units of characters.

This bash script accepts the user's name and then outputs the name and the number of characters.  In this case, it was necessary to subtract 1 from the ''wc -l''...as ''wc -l'' returns the number of lines +1

<file bash http://lab46.corning-cc.edu/~mcooper6/downloads/bash/nametest>
#!/bin/bash

#
# a program that propts for a name, counts the characters
# and outputs the results

echo -n "Please enter your name "
read name;

chars=$((`echo $name | wc -c` - 1))

echo "Your name is $name it has $chars characters"
</file>

===numguess===
  *Write a “guess the number” game that allows the user 4 chances to guess the number.

This script generates a random number between 1 and 10.  The user is allowed to guess 4 times before the number is given.

<file bash http://lab46.corning-cc.edu/~mcooper6/downloads/bash/numguess>
#!/bin/bash

RANGE=10
rand=$(($RANDOM%$RANGE))
thisFlag=1
tries=1
while [ $thisFlag -eq 1 ]
do

        echo "Guess a number between zero and ten "
        read num

        if [ $num -eq $rand ]; then
                echo "Got it!"
                thisFlag=0
        else
                if [ $tries -gt 3 ]; then
                        echo "The number is $rand"
                        thisFlag=0
                else
                        echo "Sorry. Try again"
                fi
        fi
        tries=$(($tries+1))
done
</file>
===stringtest===
  *Prompt the user for some text, store it in a variable. Convert any uppercase letters to lowercase and store that in a separate variable. Display the before and after.

I used the ''tr'' utility in the script to translate a string to lower case.  Simply flip the ''"[:upper:]"'' and  ''"[:lower:]"'' to convert the opposite way.
<file bash http://lab46.corning-cc.edu/~mcooper6/downloads/bash/stringtest>
#!/bin/bash

echo -n "Enter a string "

read theString

lower=`echo "$theString" | tr "[:upper:]" "[:lower:]"`

echo "You entered $theString"
echo "Lower case: $lower"

</file>
===logcount===
  *Write a script that counts how many times you've logged in this month.
This script is pretty short, in fact, it was taken from timebandit (see below).  This line will provide you with the number of lines output by the ''last'' utility. (Truth be known, it's probably better to subtract one or two from this one too, as ''last'' outputs a couple additional lines)
<file bash http://lab46.corning-cc.edu/~mcooper6/downloads/bash/logcount>
#!/bin/bash

echo "You've been logged in "`last $USER | wc -l`" times"
</file>
===filejoin===
  *Create two or three sample text files, and write a script that simulates a database-y operation (like SELECT, VIEW, or JOIN– not all, just pick one and do it, commenting on what that operation should do, and how you've accomplished it)

In this case, I first created a program that creates files.  ''filemaker'' is a short script that cuts the output of ''last'' into "fields" based on the position of the colon (:).  Using the -f1 option returns field one (left side of the : ); -f2 returns field 2 and so on.  I also grepped out (using -v to invert) the "Still logged in" and "no logout" entries.  Then, write these to a file by redirecting standard out to a file with the ''>>'' operator. (''>'' overwrites)

After that, filejoin simply puts it all back together using the ''paste'' utility into a third file.
===filejoin===
<file bash http://lab46.corning-cc.edu/~mcooper6/downloads/bash/filejoin>
#!/bin/bash

paste -d- test_logfile1 test_logfile2 > test_logfile3

</file>
===filemaker===
<file bash http://lab46.corning-cc.edu/~mcooper6/downloads/bash/filemaker>
#!/bin/bash
#
# a program that makes 2 files

last | grep -v 'still logged in' | grep -v 'gone - no logout' | cut -d':' -f1 >> test_logfile1

last | grep -v 'still logged in' | grep -v 'gone - no logout' | cut -d':' -f2 >> test_logfile2

</file>
===webtest===

  *Write a script that, when run, will download a web page and compare it to an existing, but older, copy of the webpage and displays any differences OR performs a line/word count; then rename the current copy to a backup, and remove the old backup in preparation for the next run- you might want to do this on some web page whose HTML output might change somewhat regularly (digg, slashdot, google news, etc.)

This script uses ''wget'' to download a web page.  After that, the lines of that file (called index.html) are counted and stored in the variable n_count.  Then, the lines of a file called index.html.BU are gathered and counted and stored in a variable called o_count. Next, the two values are compared.  If the older file (o_count) has more lines than (-gt for greater than) the new file (n_count), it echos "More"; if it has less it echos "Less" otherwise, it must be equal.

After everything's finished, the contents of the new file (index.html) are written over the contents of the old file (index.html.BU) and the new file (index.html) is deleted.

<file bash http://lab46.corning-cc.edu/~mcooper6/downloads/bash/webtest>
#!/bin/bash

wget http://www.yahoo.com

n_count=`cat index.html | wc -l`

o_count=`cat index.html.BU | wc -l`

echo "Counting lines..."

if [ $o_count -gt $n_count ]; then

        echo "The web page has more lines now"

elif [ $o_count -lt $n_count ]; then

        echo "The web page has less lines now"

else

        echo "The web page has the same number of lines"

fi

echo "Old count is $o_count, the new count is $n_count"
echo "Backing up ..."
cat index.html > index.html.BU

echo "Cleaning up..."
rm -rf index.html

echo "Done"

</file>

===timebandit===
  *Devise and implement a simple script of your own whose purpose is well-defined, and implementation well-documented.

This scripts has some interesting points within.  This script will output the amount of time each user has been logged into Lab46 for the current month.  The script can be called from the command line by itself, or it can be called with arguments, in the form of user names.

<cli>

@lab46:~$ ./timebandit 

@lab46:~$ ./timebandit $USER

</cli>

The logic is as follows:
  *Check to see if there are command line arguments
    *If there are command line arguments, use those usernames, otherwise get a list from the home directory
  *After that, loop through the list of users and get each users days, hours and minutes.
    *Loop through the list of days, hours and minutes to compress into the smallest possible (I.E. 120 min -> 2 hours .... 48 hrs -> 2 days)
  *Next, use the final value of days, hours and minutes to control the loops that output the "chart".
  *When it's all done, reset the variables to zero and have another go at it.

<file bash http://lab46.corning-cc.edu/~mcooper6/downloads/bash/timebandit>
# A program that uses the last utility to determine the time that
# each student is logged on for the current month
# This program can be invoked by passing the students username as
# an arguement, which returns the logged time for that student;
# or the program can be invoked with no arguments to retrieve a
# list of all users' logged time


# check to see if the program has been invoked with arguements
# if yes, use those username, if no use the entire class list

if [ -z "$*" ];then
        users="`last | sort | sed -e 's/^\([a-z][a-z0-9]*\).*$/\1/' | uniq`"
else
        users="$*"
fi

# loop through the list to retrieve logged times
for n in $users; do

        days="`last | grep $n | grep -v 'still logged in' | grep -v 'gone - no logout' | grep '+' | sed -e 's/^.*(\(.*\)).*$/\1/' | cut -d':' -f1`"

        hours="`last | grep $n | grep -v 'still logged in' | grep -v 'gone - no logout' | sed -e 's/^.*(\(.*\)).*$/\1/' | cut -d':' -f1`"

        minutes="`last | grep $n | grep -v 'still logged in' | grep -v 'gone - no logout'| sed -e 's/^.*(\(.*\)).*$/\1/' | cut -d':' -f2`"

        # loop through the list of hours, removing leading zeros
        # and adding the remaining numbers together
        for h in $hours;do

                # check for '+' in case there's more than 24 hours
                chk=`echo $h | grep '+' | wc -l`

                #totaldays=0
                #days=0

                if [ $chk -eq 0 ]; then
                        # not more than 24 hours
                        h="`echo $h | sed -e 's/^0\([1-9][0-9]*\)/\1/'`"
                else

                        # get the number of days, then add it up as d
                        days="`echo $h | cut -d '+' -f1 | sed -e 's/^0\([1-9][0-9]*\)/\1/'`"
                        let totaldays=$totaldays+$days

                        # use the logic above to get h
                        h="`echo $h | cut -d '+' -f2 | sed -e 's/^0\([1-9][0-9]*\)/\1/'`"
                fi

                # add the hours extracted to totalhrs
                let totalhrs=$totalhrs+$h
                let totaldays=$totaldays+0
        done

        # loop through the list of minutes, removing leading zeros
        # and adding the remaining numbers together
        for m in $minutes;do
                m="`echo $m | sed -e 's/^0\([1-9][0-9]*\)/\1/'`"
                let totalmin=$totalmin+$m
        done


        # devide totalminutes by 60 to extract the number of hours
        # add hours extracted to hrs and leave the remaining minutes in min
        hrs=$(($totalmin/60))
        min=$(($totalmin-$(($hrs*60))))

        # add totalhrs to hrs
        hrs=$(($hrs+$totalhrs))

        # devide hrs by 24 to extract days from hrs, then add totaldays to get final number of  days
        days=$(($hrs/24))
        hrs=$(($hrs-$(($days*24))))
        days=$(($days+$totaldays))

        for ((nn=0; nn<$days; nn++ ));do
                dbar=$dbar"@"
        done

        for ((nnn=0; nnn<$hrs; nnn++)); do
                hbar=$hbar"#"
        done

        for ((nnnn=0; nnnn<$min; nnnn=nnnn+10 )); do
                mbar=$mbar"."
        done

        echo "-----------------+------+"

        bar="$dbar $hbar $mbar"

        printf " %-8s | %-2s : %-2s : %-2s | %-2s %-2s %-2s \n" $n $days $hrs $min $dbar $hbar $mbar

        #echo "$n | $days days : $hrs hours : $min min | $dbar $hbar $mbar"
        #echo "$n | $h"

        bar=""
        hbar=""
        dbar=""
        mbar=""
        totalmin=0
        totalhrs=0
        totaldays=0
        days=0
        hrs=0
        min=0
done

</file>

====.bashrc====

Fun may be had with the ~/.bashrc file in your home directory.  Here's my simple, yet helpful .bashrc:

<code bash>

##
## automagically ls files after CD
##

cdl()    {
  cd "$@";
  ls -Alh --color=auto;
}

alias cdl=cdl

##
## auto update in 3 chars ... remove the -y if you please
##

alias upd='sudo apt-get -y update && sudo apt-get -y upgrade'

##
## move around the file system a bit more swiftly
##

alias ..='cd ..' 
alias .2='cd ../..'
alias .3='cd ../../..'
alias .4='cd ../../../..'
alias .5='cd ../../../../..'

##
## get me home
##

alias home='cd ~/'

##
## edit those pesky priviliged files a bit faster
##

alias svi='sudo vi'

##
## give me more information ... but only when I want it
##

alias lls='ls -lAh --author --color=auto'

##
## show me what's open in a pinch
##

alias ports='netstat -tulanp'

##
## edit the hosts file
##

alias hosts='sudo vi /etc/hosts'

</code>
====IRC====
  *[[rene|Rene the Lady Bot]]

====jobs====

List all running jobs:

<cli>

:~$ jobs

</cli>


List process ID (PID) of all running jobs:

<cli>

:~$ jobs -p

</cli>


Kill all running background jobs:

<cli>

:~$ sudo kill -9 $(jobs -p)

##
## or
##

:~$ sudo kill `jobs -p`

</cli>
====Networking====
Useful network connection Commands
  *List IP address (similar to ipconfig in Windows)
<cli>
lab46:~ ifconfig
</cli>
  *Show wireless networks that are available in the area along with basic encryption information
<cli>
lab46:~ iwlist scan
</cli>
  *Show interface and driver associated with each networking device
<cli>
lab46:~ lshw -C network
</cli>
  *Show hardware connected to the pci bus
<cli>
lab46:~ lspci -nn
</cli>
  *Show USB connected hardware
<cli>
lab46:~ lsusb
</cli>
  *Additional info on USB related hardware (good for USB dongles)
<cli>
lab46:~ lshw -C usb
</cli>
  *List modules that will not be loaded by the Operating System at boot time
<cli>
lab46:~ cat /etc/modprobe.d/blacklist
</cli>
  *List currently loaded kernel modules. (Example usage - lsmod | grep ndiswrapper)
<cli>
lab46:~ lsmod
</cli>
  *List kernel IP routing table -- Good for troubleshooting problems with the gateway (netstat -rn = equivalent command)
<cli>
lab46:~ route -n
</cli>
  *Set the default gateway to 192.168.1.1
<cli>
lab46:~ sudo route add default gw 192.168.1.1
</cli>
  *Delete the default gateway setting
<cli>
lab46:~ sudo route del default gw 192.168.1.1
</cli>
  *Load the kernel module ****
<cli>
lab46:~ sudo modprobe *****

Example usage:
lab46:~ sudo modprobe ndiswrapper
lab46:~ sudo modprobe r818x
lab46:~ sudo modprobe ath_pci

</cli>
  *Unload the kernel module ****
<cli>
lab46:~ sudo modprobe -r ****

Example usage:
lab46:~ sudo modprobe -r ndiswrapper
</cli>
  *Bring up/down the interface and clears the routing table for the specified interface
<cli>
lab46:~ sudo ifup eth0

lab46:~ sudo ifdown eth0

</cli>
  *Bring up/down the interface for the specified interface
<cli>
lab46:~ sudo ifconfig eth0 up

lab46:~ sudo ifconfig eth0 down
</cli>
  *Request IP address from DNS server for specified interface
<cli>
lab46:~ sudo dhclient
</cli>
  *Release IP address associated with specified interface
<cli>
lab46:~ sudo dhclient -r
</cli>
  *List firewall rules
<cli>
lab46:~ sudo iptables -L
</cli>
  *List boot log -- good for troubleshooting problems with modules/drivers not being loaded
<cli>
lab46:~ dmesg | more
</cli>
  *Display kernel version
<cli>
lab46:~ uname -r
</cli>
  *(Feisty and pre-releases (Edgy, etc)) - /etc/udev/rules.d/70-persistent-net.rules (Gutsy) - File which assigns logical names (eth0, wlan0, etc) to MAC addresses
<cli>
lab46:~ /etc/iftab
</cli>
  *List DNS servers associated with network connections (Network Manager)
<cli>
lab46:~ cat /etc/resolv.conf
</cli>
  *File which sets or modifies dns (domain name servers) settings
<cli>
lab46:~ cat /etc/dhcp3/dhclient.conf
</cli>

  * http://ubuntuforums.org/showthread.php?t=571188
  * [[dell_latitude_d531_wifi|Dell Latitude D531 Wireless Network Setup]]
====ps & kill====
While installing a bot on Lab46, I found that I was going to have to kill the bot's processes (over and over again).  I learned that a simple ''ps'' command would lead me to the information I needed.

<cli>
:~$ ps
</cli>

The ''ps'' command retrieves a list of all the processes currently running under your account.  To find all the processes on the system, use the ''aux'' option:

<cli>
:~$ ps aux
</cli>

With list in hand (or in terminal) I picked out the process ID (PID) of my unsuspecting bot and pulled the trigger:

<cli>
:~$ kill <pid>
</cli>

====screen====
A few tricks in ''screen'' that make it easier to debug applications.  When using multiple screen processes, it's not a bad idea to name each processes.  Do this with the following line:

<cli>
# ...replace <name> with ... well ... a name
:~$ screen -S <name>
</cli> 

The above command opens a new screen session containing a second bash shell.  Now, with multiple screens open, after you detach using ''ctrl + a + d'' you can list your open screen sessions with the following command:

<cli>
:~$ screen -ls
</cli>

Reattach as you normally would, except now give screen the name of the session you seek:

<cli>
:~$ screen -r <name>
</cli>

Handy.

====sudoers====
After users have been added, it's helpful to give some users a little extra access.  This can be done with sudo.  To give a user sudo access, edit the sudoers file with the command visudo.  visudo is a special utility that allows root to manage the sudoers file with a little bit of back-end syntax checking to make sure that you don't make a mistake. (visudo's default editor is nano, though it can be changed to us vi ... as its name would imply.)
<cli>
:~$ visudo
</cli>
Adding the following line to the sudoers file will give a user root privileges, except that they cannot change the root password.
<cli>
user ALL = (ALL) ALL, !/usr/bin/passwd root
</cli>
===Useful Links===
  * [[http://aplawrence.com/Basics/sudo.html|Using Sudo]]
====useradd====
Adding users requires the following command: (again with sudo)
<cli>
:~$ sudo useradd -gadm -gunix -pxxxx -d/home/$USER -m $USER
</cli>
(where $USER is your desired username)

The above command adds a user to the groups (-g) adm and unix.  There is a difference between capital G and lowercase g, as the capital G will not actually add you to the desired group.  However, you can manually add yourself to groups by directly editing the file etc/group.  However, since most users don't have root access, this again requires sudo:

<cli>
:~$ sudo vi etc/group
</cli>

Once open, find the ''adm'' and ''unix'' entries and add your new user's name to the end of the list. (no points for being first)

<WRAP warning>
Using the -p option of the useradd command doesn't encrypt your password in the etc/shadow file.  Additionally, if the password is not encrypted, the system doesn't like to let you authenticate.
</WRAP>
To see what I mean, issue the following command: (you may want to pipe this to less)
<cli>
:~$ sudo cat etc/shadow | less
</cli>
Scroll through the file and see that the password you entered with the -p option of the useradd command is there in plain text for all to see.  Whoops.  Now, attempt to authenticate with the following command:

<cli>
:~$ su $USER
</cli>
You will be prompted for your password.  No dice huh?  To fix this, as ROOT, issue the following command:
<cli>
:~$ sudo passwd $USER
</cli>
Again, substitute $USER with your new user's name.  You will then be prompted for the new password, and, once complete, the NEW password will be hashed.

=====VMWare=====

If you've ever locked yourself out of a box, you've probably used single user mode to recover the password.  As easy as this is with bare metal, it is less so inside a VMWare virtual machine ... particularly if you happen to be running Ubuntu server which speeds happily past the boot menu upon startup.  This trick is helpful:

<cli>

##
## edit the .vmx file for your VM adding the following
##

:~$ vi /vmdk/volumes/datastore1/<vm folder>/<vm name>.vmx

##
## add this line to slow down the boot to give you time to hit F2 or whatever needs hitting
##

bios.bootDelay = "15000"

</cli>

Now, hit your F2 and **select recovery mode**.  From here, mount the drive in read/write mode. (this works in all Linux recovery mode situations)

<cli>

##
## remount the drive in read/write mode
##

:~$ mount -o remount,rw /

##
## you are now root
##


</cli>

====CLI====

You need to enable ssh before using the CLI within ESXi. Currently, the only way I know of doing this remotely is throught the VMWare vSphere client (Windows/Mac OS X). (See vim-cmd hostsvc disable_ssh for a method of turning this off remotely)

From the client: click the host -> click the configuration tab -> click security profile -> under services click properties -> highlight ssh -> click options -> click start.

You can now ssh into the ESXi host.

===Restart a VM===

Begin by listing the running VM processes

<cli>

:~$ esxcli vm process list

##
## Likely output ... shows 2 VMs running ... note the World ID
##

ubuntu-vm
   World ID: 1361123
   Process ID: 0
   VMX Cartel ID: 1361122
   UUID: 56 4d 20 bb dd 70 c4 80-e0 c6 f7 a6 ee 51 ee 25
   Display Name: ubuntu-vm
   Config File: /vmfs/volumes/509298eb-d48bf52f-d03d-842b2b5c1eb7/ubuntu-vm/ubuntu-vm.vmx

debian-vm
   World ID: 1341691
   Process ID: 0
   VMX Cartel ID: 1341690
   UUID: 56 4d 18 73 98 73 59 c3-3e 71 44 ff 15 58 17 1e
   Display Name: debian-vm
   Config File: /vmfs/volumes/509298eb-d48bf52f-d03d-842b2b5c1eb7/debian-vm/debian-vm.vmx

</cli>

Next, use ''vim-cmd'' to restart any given VM using the path to its .vmx file.  (This can also use the VM's world ID)

<cli>

:~$ vim-cmd vmsvc/power.reboot /vmfs/volumes/datastore1/ubuntu-vm/ubuntu-vm.vmx

</cli>

===Clone a VM===

<cli>

:~$ vmkfstools -i /vmfs/old/path.vmdk -d thin /vmfs/new/path.vmdk

</cli>

Next, to register the VM in the datastore, first copy the .vmx file into the newly created VM directory.

<cli>

##
## copy the .vmx file
##

:~$ cp /vmfs/old/path.vmx /vmfs/new/path.vmx

##
## register the VM
##

:~$ vim-cmd solo/registervm /vmfs/new/path.vmx

</cli>

===Regenerate a Missing (corrupted) .vmdk===

Given a vm named slugworth, and a missing .vmdk file or corrupted ... here's how to regenerate:

First, identify the size of the file slugworth-flat.vmdk

<cli>

##
## navigate to the directory of ...
##

:~$ cd /vmfs/volumes/datastore1/slugworth


##
## determine its size
##

:~$ ls -l 

-rw-------    1 root     root     17179869184 Feb  4 14:10 slugworth-flat.vmdk  <---- FROM THIS LINE ... 17179869184
-rw-------    1 root     root          8684 Feb  4 14:10 slugworth.nvram
-rw-------    1 root     root           493 Feb  4 14:09 slugworth.vmdk
-rw-r--r--    1 root     root             0 Nov  1 19:42 slugworth.vmsd
-rwxr-xr-x    1 root     root          2746 Feb  4 14:10 slugworth.vmx
-rw-r--r--    1 root     root          3423 Nov  5 19:13 slugworth.vmxf
-rw-r--r--    1 root     root        124730 Jan  4 13:12 vmware.log

</cli>

Identify the type of SCSI controller the virtual disk is using by opening the .vmx file ...

<cli>

##
## determine the SCSI controller ... vitrualDev
##

:~$ cat slugworth.vmx | grep -i scsi

scsi0.present = "TRUE"
scsi0.sharedBus = "none"
scsi0.virtualDev = "lsilogic"  <---- THIS LINE
scsi0:0.present = "TRUE"
scsi0:0.fileName = "ubuntu.vmdk"
scsi0:0.deviceType = "scsi-hardDisk"
scsi0.pciSlotNumber = "16"
scsi0:0.redo = ""

</cli>

Use the vmkfstools command to create a new virtual disk:

<cli>

##
## create a new disk
##

:~$ vmkfstools -c 17179869184 -a lsilogic -d thin temp.vmdk



##
##    -c size
##
##        This is the size of the virtual disk.
##
##    -a virtual_controller
##
##        Whether the virtual disk was configured to work with BusLogic, LSILogic (for both lsilogic and lsilogic SAS) or IDE.
##
##    -d thin
##
##        This creates the disk in thin-provisioned format.
##

</cli>


Delete the un-needed temporary flat.vmdk

<cli>

:~$ rm -rf temp-flat.vmdk

</cli>

Edit the new temp.vmdk and change the name of the .flat file to match the orphaned .flat file, and find and remove the line ddb.thinProvisioned = "1" if the original .vmdk was not a thin disk. If it was, retain this line.

<cli>

:~$ vi temp.vmdk

# Disk DescriptorFile
version=1
CID=fb183c20
parentCID=ffffffff
createType="vmfs"

# Extent description
RW 8388608 VMFS "temp-flat.vmdk"  <--- CHANGE THIS LINE

# Extent description
RW 8388608 VMFS "slugworth-flat.vmdk"  <--- TO THIS LINE


# The Disk Data Base
#DDB

ddb.virtualHWVersion = "4"
ddb.geometry.cylinders = "522"
ddb.geometry.heads = "255"
ddb.geometry.sectors = "63"
ddb.adapterType = "lsilogic"
ddb.thinProvisioned = "1"  <---- REMOVE THIS LINE IF NOT THIN PROVISIONED

</cli>

Optionally, check the disk consistency

<cli>

##
## check disk consistency ... esxi 5.0 or later
##

:~$ vmkfstools -e filename.vmdk
Disk chain is consistent

##
## check disk consistency ... esxi 5.0 or earlier
##

:~$ vmkfstools -q test.vmdk
test.vmdk is not an rdm

</cli>

Now start the VM.

Instructions taken from: [[http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1002511|Recreating a missing virtual machine disk (VMDK) descriptor file]]

===vim-cmd===

<cli>

##
## Options available under vim-cmd
##

hbrsvc/       internalsvc/  solo/         vmsvc/        
hostsvc/      proxysvc/     vimsvc/       help

</cli>

==vmsvc==

<cli>

##
## other options available under vim-cmd vmsvc/
##

acquiremksticket                 get.snapshotinfo                 
acquireticket                    get.spaceNeededForConsolidation  
connect                          get.summary                      
convert.toTemplate               get.tasklist                     
convert.toVm                     getallvms                        
createdummyvm                    gethostconstraints               
destroy                          login                            
device.connection                logout                           
device.connusbdev                message                          
device.disconnusbdev             power.getstate                   
device.diskadd                   power.hibernate                  
device.diskaddexisting           power.off                        
device.diskremove                power.on                         
device.getdevices                power.reboot                     
device.toolsSyncSet              power.reset                      
device.vmiadd                    power.shutdown                   
device.vmiremove                 power.suspend                    
devices.createnic                power.suspendResume              
disconnect                       queryftcompat                    
get.capability                   reload                           
get.config                       setscreenres                     
get.config.cpuidmask             snapshot.create                  
get.configoption                 snapshot.dumpoption              
get.datastores                   snapshot.get                     
get.disabledmethods              snapshot.remove                  
get.environment                  snapshot.removeall               
get.filelayout                   snapshot.revert                  
get.filelayoutex                 snapshot.setoption               
get.guest                        tools.cancelinstall              
get.guestheartbeatStatus         tools.install                    
get.managedentitystatus          tools.upgrade                    
get.networks                     unregister                       
get.runtime                      upgrade 

</cli>

==solo==

<cli>

##
## Options available under vim-cmd solo/
##

connect          environment      logout           querycfgoptdesc  
disconnect       login            querycfgopt      registervm

</cli>

==hbrsvc==

<cli>

##
## Options available under vim-cmd hbrsvc/
##

vmreplica.abort                  vmreplica.pause                  
vmreplica.create                 vmreplica.queryReplicationState  
vmreplica.disable                vmreplica.reconfig               
vmreplica.diskDisable            vmreplica.resume                 
vmreplica.diskEnable             vmreplica.startOfflineInstance   
vmreplica.enable                 vmreplica.stopOfflineInstance    
vmreplica.getConfig              vmreplica.sync                   
vmreplica.getState

</cli>

==hostsvc==

<cli>

##
## Options available under vim-cmd hostsvc/
##

advopt/                   enable_ssh                refresh_services          
autostartmanager/         firewall_disable_ruleset  reset_service             
datastore/                firewall_enable_ruleset   runtimeinfo               
datastorebrowser/         get_service_status        set_hostid                
firmware/                 hostconfig                standby_mode_enter        
net/                      hosthardware              standby_mode_exit         
rsrc/                     hostsummary               start_esx_shell           
storage/                  login                     start_service             
summary/                  logout                    start_ssh                 
vmotion/                  maintenance_mode_enter    stop_esx_shell            
connect                   maintenance_mode_exit     stop_service              
cpuinfo                   pci_add                   stop_ssh                  
disable_esx_shell         pci_remove                task_list                 
disable_ssh               queryconnectioninfo       updateSSLThumbprintsInfo  
disconnect                querydisabledmethods      
enable_esx_shell          refresh_firewall

</cli>

==internalsvc==

<cli>

##
## Options available under vim-cmd internalsvc/
##

perfcount/          host_mode_lock      refresh             set_log_level       
vprobes/            login               refresh_consolenic  shutdown            
access_address      loglist             refresh_datastores  throw_exception     
cold_quit           logout              refresh_gateway     use_fds             
connect             redirect_stderr     refresh_network     
disconnect          redirect_stdout     refresh_pnic

</cli>

==proxysvc==

<cli>

##
## Options available under vim-cmd proxysvc/
##

add_np_service   disconnect       port_info        
add_tcp_service  login            remove_service   
connect          logout           service_list

</cli>

==vimsvc==

<cli>

##
## Options available under vim-cmd vimsvc/
##

auth/             license           property_dump     task_info         
connect           login             task_cancel       task_list         
disconnect        logout            task_description

</cli>


====Resources====
  *[[http://www.vm-help.com/esx40i/|Managing ESXi without the VI client]]