The Subroutine

This code can be placed in a script or in a separate module.

 1: use Term::ReadKey;
 2:
 3: sub getPromptOption ($$)
 4: {
 5: 	my $prompt  = shift;
 6:	my $options = shift;
 7:	my $choice;
 8:
 9:	ReadMode 'cbreak';
10:	print $prompt;
11:	$choice = ReadKey(0) until $choice =~ m/[$options]/;
12:	ReadMode 'normal';
13:	return $choice;
14: }

Obviously, the Term::ReadKey must be loaded first (line 1). The getPromptOption() subroutine accepts two mandatory parameters as indicated by the declared prototype (line 3). Additional field-validation logic may be desired, but is omitted here for brevity. The terminal’s “read” mode is changed to cbreak, which accepts a single character as input (line 9). The prompt that was passed into the subroutine is printed on the screen (line 10) and then the program enters a loop that reads characters from keyboard input until one of the valid options is entered (line 11). Once a valid key has been pressed, the read mode is returned to normal mode (input accepted until the Enter key is pressed; line 12) and the chosen option is returned to the calling logic (line 13).

Usage

This is a very contrived routine that illustrates the use of the subroutine described above. It allows the user to increment or decrement a current value.

 1. my $i = 0;
 2. my $action = '';
 3. print "Current value: $i\n\n";
 4. until ( $action =~ m/[Xx]/ ) {
 5.	$action = getPromptOption(
 6.		"Select Action: [I]ncr, [D]ecr, or E[X]it",
 7.		"IiDdXx"
 8.	);
 9.	$i++ if ( $action =~ m/[Ii]/ );
10.	$i-- if ( $action =~ m/[Dd]/ );
11.	print "\n\nCurrent value: $i\n\n";
12. }

The iterator (“$i”) is set to an initial value of zero (line 1) and the next action flag (“$action”) set to null (line 2). The current value is printed on the screen (line 3) so that the user knows what it is. Next, the user is prompted to increment or decrement the value, or to exit the program (lines 5-8). If the user chooses to change the value by pressing the “i” key (line 9) or the “d” key (line 10), then the value is printed again on the screen for the benefit of the user (line 11). If the user presses the “x” key, the loop ends (line 4) and process control flows out to the end of the script. Please notice that both the upper- and lower-cases are valid options (line 7), but that the program is indifferent to which is used (lines 4, 9, 10).

Disclaimer: I’m sure the recipes on the sites below are great. I can’t say that I’ve ever actually made any of them. I’m showing off TiddlyWiki, not endorsing recipes.

Jackson Boyle’s Kitchen. Mr. Boyle’s blog includes a TiddlyWiki recipe book. The site is no longer around, but the recipes are still available here on the Wayback Machine.

Philosophical Gourmet Cookbook. The Philosophy department of the University of Florida once published a gourmet cookbook online. The link is now dead, but a copy can be found here on the Wayback Machine.

Hackers Handbook
Wow! A reference manual on how to hack! It’s an Android app and costs $6.99. One reviewer gave it a 3.4-star rating and explained that all of the material was available online for free.

How To Make Bouncing Polymer Balls
This three-part series explains how to make polymer bouncy balls using household products.

Notepad. Believe it or not, this ‘blog began as a TiddlyWiki…sort of. I wanted to publish my notes on a number of topics on a free “personal” page. Cobbling pages together by hand was too labor-intensive, especially when I wanted to change the look-and-feel of the whole site at one time. I wasn’t learned in CSS at the time and I tried automating the compilation of a site using flat data files, HTML templates, make, and a few other scripting utilities. All of it was taking up way too much time. TiddlyWiki was the answer. For a very good reason (which now escapes me), I decided to use ‘blog technology instead, which has worked out far better in the long run; however, I might not have made that leap without TiddlyWiki in the middle.

School Notes. I finally broke down and bought a laptop while I was in graduate school. This allowed me to take all of my notes electronically, at least for the last couple of years in the program. I really wanted to go paperless, so I relied on scans, downloads, and other methods for keeping it all digital. I even recorded lectures on occasion. TiddlyWiki was my notebook of choice. With a wiki mindset, I would create Tiddlers for topics and then referenced them from Tiddlers containing basic outlines of both textbook chapters and lectures. Doing most of the work before hand allowed me to take minimal notes during class, which meant that I could pay more attention to the professor and participate in the discussion more fully.

Big Finish. The proverbial icing on the cake came in my capstone course. The professor (who happened to be the department chair) believed heavily in the power of organization. A student who keeps an organized and complete notebook will always do well, he would tell us often. As such, we had to turn in our class notebooks to the professor at the end of the semester – for a grade! I hadn’t done that since, oh let’s see, high school! It was degrading, but admittedly, a very wise requirement on his part. I had one little problem. I told him that I could print out the contents of my “notebook”, but with his permission I’d rather turn in a 100%-electonic copy. He agreed, so long as it was easily viewed on his PC with little effort. Everything was linked in the TiddlyWiki. I just burned the CD and wrote the instrucitons on the label: “insert into CD-ROM drive and open notebook.html”. I guess it worked, because I aced the course. He retired the next year.

The Data File

Any ASCII text file can be used with the following examples. I use “myfile.txt” for illustrative purposes, and for me, it is a twenty-line file that contains consecutive numbers on each line (line 1 is “1″, line 2 is “2″, etc.). The following code creates this data file and quickly resets it as needed.

1: open (OUT,">myfile.txt");
2: print OUT join("\n",1..20);
3: close OUT;

Basic Example

This is a very basic example for using Tie::File. It just prints the contents of an array on the screen.

1: use Tie::File;
2: my @records;
3: tie @records, 'Tie::File', "myfile.txt";
4: print join ( "\n", @records );
5: untie @records;

The module must first be loaded using the use function (line 1). Next, an array is defined that will be tied to the file (line 2). The tie command is where the magic happens (line 3). Now the lines in the file can be operated upon as though they were just elements in an array. The print/join function is a common way to print an array tot he screen (line 4). The untie function releases the file (line 5), though this is often omitted due to laziness.

Direct Access

Reading a file and printing records is only so much fun. Here’s an example of how to change a single line in the file directly.

1: use Tie::File;
2: my @records;
3: tie @records, 'Tie::File', "myfile.txt";
4: $records[9] = "foo";
5: print join ( "\n", @records );
6: untie @records;

This is the same code as before, except that line 4 has been injected. It is a simple assignment that changes the tenth line of the file to “foo”. Remember that PERL arrays are zero-based, so $records[9] is actually the tenth element in the array.

Autochomp

Notice that newlines must either be chomped on input or readded for output. This is handled automatically.

Windows Newlines

Here’s an interesting trick if you are using PERL on Windows. Consider the following code.

1: use Tie::File;
2: my @records;
3: tie @records, 'Tie::File', "myfile.txt";
4: $records[9] = "foo\nbar";
5: print join ( "\n", @records );
6: untie @records;

Adding a newline character (“\n”) to the array element value will only embed it in the string. Inspect the file afterward, and find that no new line has been created in the file, even though it appears from the screen output that one had been added. Since line endings in Windows are two characters instead of one, carriage-return and linefeed, you must prepend the other character (“\r”).

1: use Tie::File;
2: my @records;
3: tie @records, 'Tie::File', "myfile.txt";
4: $records[9] = "foo\r\nbar";
5: print join ( "\n", @records );
6: untie @records;

Now the file does show an additional line. Of course, there are much better ways of doing this.

Changing Record Separators

Much like the RS and ORS variables in AWK, the record separator can be changed to any text string. This is done when the file is tied. Only this line is presented here.

1: tie @records, 'Tie::File', "myfile.txt", recsep => 'zap';

Now, the file will be separated into records on every occurence of the string ‘zap’. I don’t want to spend the time to write and test a working example for this, as the need for this sort of thing may never arise in my work. It was just interesting to note.

Splicing

To remove one or more lines from a tied file, use the splice command.

1: use Tie::File;
2: my ( @records, @removed );
3: tie @records, 'Tie::File', "myfile.txt";
4: @removed = splice(@records,1,3);
5: print join ( "\n", @records );
6: untie @records;

Again, this is the same code we’ve been using, except an additional array has been declared (line 2) and the splice command has been introduced to remove the second, third, and fourth lines from the file (line 4). The first parameter of the splice function is the array, the second is the offset from the beginning of the array (one element), and the third is the length of the slice to be removed (three elements).

Here’s how elements can be replaced.

1: use Tie::File;
2: my ( @records, @removed );
3: tie @records, 'Tie::File', "myfile.txt";
4: @removed = splice(@records,1,3,26);
5: print join ( "\n", @records );
6: untie @records;

The same records are removed as above, but one new element has been inserted in their place with a value of 26.

Push, Pop, Shift, Unshift

All of these functions have splice equivalents, but they can be used as they normally would to manipulate the tied file.

Iteration

Random access is nice, but sometimes it is necessary to iterate through the records in a file. The following illustrates how to print the contents of the array to the screen by iteration instead of using print/join.

1. use Tie::File;
2. my ( @records, $record );
3. tie @records, 'Tie::File', "myfile.txt";
4. foreach $record ( @records ) { print "$record\n"; }
5: untie @records;

In addition to declaring the array, a record scalar is defined (line 2). The foreach iterator is used as one would expect to traverse through the array from beginning to end. A for loop could have been used just as easily.

Touareg (Moroccan Mint) Organic Green Tea. [World Market; ~$66.67] In the queue.

Observations

• I received a reading plan from my friend that listed all of the readings. I tried to find a copy online, but apparently they are only available in the E100 store. The 136-page guide costs about $10, and the daily planner is only availble in packs of 25 for just under $13 (all prices as of 12/29/2011). So as not to deprive the company of revenue, I will not directly reproduce the list here.
• The plan did contain a shortened version of The Scripture Union Bible Reading Method (SUBRM). This method is almost identical to Lectio Divina, which was developed over time (primarily) between the 4th and 12th centuries (sources vary as to events that attribute to this development, the details of which are irrelevant here).

My Narrative

The SUBRM involves reflecting upon the Scriptures, asking questions. This correlates to the Lectio Divina practice of meditatio. It recommends writing the answers in a journal or notebook. This narrative is my E100 journal. One caveat: in my experience, Lectio Divina is usually applied to much smaller passages, not one or two whole chapters at one time, so I will focus on key points each day.

Since I am starting this part late, I will have to catch up…

OLD TESTAMENT

1. God created the world and man in it. All of creation was pleasing to God, man included. He lovingly provided all that is necessary to sustain us. The whole man includes both body (dust) and soul (breath). We were made to be like God and to be with God. God asked only for us to trust in him and not in ourselves. The garden, God’s care, was given freely to man.

2. But man chose to disobey God. The result was death: not an immediate physical death, but a spiritual one. No longer a friend of God, man had forfeited God’s gifts. The protection of the garden was gone. God foreshadows that man will struggle with this choice for generations, but that an offspring of the woman will eventually conquer it.

3. As time progressed, man became so wicked that God decided to destroy his creation because of them. Only one man found favor with God on account of his righteousness. Noah obeyed God in every detail. His obedience saved not only him, but his family and other creatures from the forthcoming destruction. The flood waters came, and only the passengers of the ark were left behind.

4. When the flood waters subsided and the earth had been cleansed, Noah made an acceptable sacrifice to God. Acknowledging that it is man’s fallen nature that causes him to sin, God then made a covenant with the earth, promising that he would never again destroy creation with a devastating flood.

5. Several generations passed, and man plotted to reach heaven by building a large tower. (Jewish tradition tells us that Noah’s great-grandson, Nimrod, desired vengeance on God for the destruction of their forefathers.) Remembering his promise, God simply confused their language, preventing the completion of this ambitious and prideful project.

6. God decided to set a people apart for himself in a land of their own, beginning with a man named Abram. A special blessing is to be made upon the members of this people and a curse upon their enemies. The latter is proven true when the Egyptian Pharaoh attempts to take Abram’s wife for his own.

7. God assured Abram through a covenant promise that his blessing was to be bestowed on his own offspring upon his death. The covenant ceremony required an animal sacrifice, signifying the fate of the one who breaks it.

8. The blessing of Abram (now called Abraham) was to be inherited by his son Isaac, despite that Abraham had an older son by a servant girl. This was God’s choice that the blessing be passed on to the son born of his wife, Sarah. God then tested Abraham’s faithfulness by telling him to sacrifice Isaac, an order that Abraham followed obediently until he was stopped by God and was given an alternate victim.

9. From Isaac, the blessing was to fall on his son, Esau; however, his younger son, Jacob, deceived Isaac and received his blessing instead. Again, this was God’s will, confirmed by the Lord himself to Jacob in a dream. Once the blessing is given, it cannot be revoked and cannot be replaced with a curse. Esau vowed vengence.

10. After some time had passed, Jacob and Esau were reconciled, though Jacob had been expecting a confrontation for he knew that Esau had murderous intentions toward him in the past. While Esau was still far off, Jacob had sent gifts as a peace-offering, but these were initially dismissed by Esau. The real confrontation had actually been with a mysterious stranger the night before his meeting with Esau. Though the stranger lost the fight, he blessed Jacob, and changed Jacob’s name to Israel, “he who has contended with divinity”. God often changes the names of men after they have reached a point of transformation in their lives.

11. Israel favored his son, Joseph, who had been born of him in his old age. Joseph was blest by God with the ability to interpret dreams. His older brothers were jealous of Israel’s favor toward Joseph and sold him into slavery. The brothers convinced Israel that his son had been killed by a wild animal.

12. Joseph fared well under God’s protection. He was placed in charge of his master’s house. His master’s wife desired him, but when he refused her on the grounds that she was tempting him to sin, she accused him of rape. He was jailed, but there too, he found favor with with the jailor and was given responsibilities. While in prison, he interpreted dreams. He predicted one prisoner’s release and asked him to appeal to the Pharaoh for his own release. When Joseph satisfactorily interpreted the Pharaoh’s dreams, he was released and put in charge of the land of Egypt.

13. Ten of Joesph’s brothers were sent to Egypt to purchase food during a famine. Benjamin was not with them. Joseph recognized them, and sold them the food they required, but he also imprisoned one of the brothers, Simeon, and made his release conditional upon the presence of all eleven brothers in Egypt. The money they paid for the food was also placed secretly in their bags, so that when they returned home, they discovered that they had not paid for the goods.

14. When the food ran out, they prepared for another journey to Egypt, taking with them Benjamin, gifts for the man in charge of the food, and enough money to pay for more food as well as the food they had taken. Simeon was released and they dined on portions from Joseph’s table, still not recognizing him. As they prepared for the journey home, Joseph planted their money amongst their things once again, as well as a silver goblet in Benjamin’s bag, and had them stopped on their way to be arrested for theft. His brother Judah pleas on Benjamin’s behalf so that the favored son may go back to his father, Israel.

15. Joseph revealed his true identity to his brothers and, with assistance from the Pharaoh, sent them back to gather his father and their people and to bring them back to settle in Egypt, where he could be near them and provide for them. So, the people if Israel came to Egypt to live, and they became a numerous people.

16. A new Pharaoh eventually came into power who did not know (or did not recognize) Joseph’s contributions to Egypt. In fear of their numbers, he oppressed the Israelites, making them slaves and ordering the deaths of their newborn boys. An Israelite boy was born and, because his mother faithfully placed him in the hands of God to protect him from infanticide, he was delivered by the water into the arms of Pharaoh’s daughter who loved him and adopted him. She was his advocate to Pharaoh, pleaing on his behalf and thereby saving him from death. She named him Moses. When Moses was grown, he killed an Egyptian for treating his Hebrew kin cruelly. He fled to a foreign land, settled there and was married.

17. God heard the cry of the Israelites. He came to Moses in a vision and called Moses to go to Egypt and lead the Israelites into the land he promised to Abraham. He showed Moses the signs he would work to show them that he was with Moses. He also sent Moses’ brother, Aaron, as a spokesman.

18. The might of God was displayed in a series of plagues imposed upon Egypt. At first, the Pharaoh’s magicians could replicate these miracles (or at least claimed to be able to do so), but when they (admittedly) could no longer do the things that God was doing through Moses, Pharaoh recognized that these were the works of God. God not only proved his identity, but also his dominion over man and nature. Moreover, by some of his wonders, God set his people apart from the Egyptians. Nonetheless, Pharaoh remained obstinate.

19. Before the Israelites were delivered out of Egypt, so that they might prepare, God marked the head of their calendar and established and mandated an annual memorial sacrifice. The victim had to be an unblemished lamb, its blood used to signify the sanctity of the place of sacrifice, and its meat eaten as part of a meal along with bread and herbs. The meat was to be consumed in the first day, but the partaking of the bread was to continue for seven. This time was reserved for sacred assemblies and the preparation of the needed food. One who disobeyed in the celebration of this custom thus separated himself from the people of Israel. Indeed, the Israelites performed the sacrifice as perscribed and anyone who did not suffered the loss of the firstborn in the household, including the Egyptians. This loss was too great, and Pharaoh granted permission for the Israelites to leave Egypt.

20. Pharaoh changed his mind and pursued the Israelites into the desert. Through Moses, God delivered the Israelites across the Red Sea by parting its waters that they may walk acrosson dry land. When the Egyptians followed, God covered them with the sea, killing them all. His people were blessed, their foes cursed, just as God had promised Abraham.

21. Having delivered the Israelites from bondage in Egypt, he made a covenant bond with them: the people of Israel would be God’s most precious treasure on Earth if they obey him completely. They would be a “kingdom of priests”, a consecrated people set apart for God, making a sacrifice of themselves in dedication to him. He then told Moses to prepare the people for his coming down to the mountain. They were to sanctify themselves and wait for the confirmation of their new relationship with God signified in the sounding of a trumpet. The people were not to approach the holy, but remain faithful to their earthly spiritual leader through whom God chose to reveal himself. Indeed, through Moses he gave them ten words, rules by which they were to live their lives. After witnessing the events on the mountain, God speaking to Moses in lightening and thunder, they accepted Moses as their mediator to the divine.

22. Moses spoke with God for some time on the mountain, and the people forgot about their promise of obedience. They made a statue that they idolized as an image of God (Aaron built an altar in front of it and procalimed the next day to be a feast day of the Lord). This angered God and he wished to destroy them, but Moses interceded on their behalf, reminding God of his great love toward them and their fathers. The sin of the people did not go unpunished. Due to their zeal, the tribe of Levi was chosen and consecrated to perform ritual services for the Lord. Their first task, by which they were ordained, was to put to death many of the idolators. Moses set up a tent from which he conversed with God. No person could see God, for he hid himself in a column of cloud; but when the cloud stood outside of Moses’ tent, the people revered his presence with solemn bows. Because Moses had found favor with him, God agreed to go before the people on their journey to the land promised to Abraham and his descendants. God gave to Moses the ten words again and emphasized that the prescribed feasts were to be kept. Because he spoke with God, Moses’ face shone.

23. Moses was succeeded by his aide, Joshua. God promised to be with Joshua and urged him to observe the law he had given them, reciting it day and night. Joshua commanded his officers to prepare the people to occupy the land on the other side of the Jordan river from where they were camped. The two tribes that were already in the land apportioned for them pledged to aid their brethren in the occupation effort, to obey Joshua as they had obeyed Moses.

24. The tablets that bore the ten words of God had been placed in a container called an ark which the Levite priests would carry ahead of the people. As God had done through Moses at the Red Sea, when the feet of the priests touched the Jordan waters, it ceased to flow, allowing the people to cross on dry ground. At God’s command, Joshua had representatives from the twelve tribes mark the spot of the crossing with stones from the riverbed.

25. Jericho was the first city to be conquered. Joshua was approached by a warrior who made himself known as the commander of the Lord’s army. The Israelites had besieged Jericho and God instructed them to march around the city with the ark of the covenant for seven days. When they had completed the marches on the seventh day, and had blown ram horns and had made much noise, the walls of Jericho collapsed. The city was taken and all living creatures within were put to death (save a family spared for the help they had provided). Articles made of precious metals were collected for the Lord’s treasury, but the Israelites were not to covet the possessions of the citizens of Jericho. Joshua cursed the city, that it may never be rebuilt.

26. Once the promised land had been delivered to the Israelites, the people served God and that generation that had seen his great works passed away.

THX1138 (1971) George Lucas’ classic film! The government uses a mandatory drug program to control citizens. The story follows one man, THX1138, as he tries to make sense of it all and is punished for his rebellion.

Time Bandits (1981)

City of Lost Children (1995)

Se7en (1995)

Fallen (1998)

Pi (1998)

The Island (2005) Human clones are bred for their spare parts as a service to wealthy individuals. The problem is, they weren’t ever supposed to leave a sedated state, and the company has to create a cover-up story when it becomes necessary for their survival to wake them. This shares many elements found in THX1138 (above).

Seven Pounds (2008) I never want to see this movie again. It outwardly glorifies grave sin. Being an organ donor is noble. Killing yourself with the full consent of your will is intrinically evil and a mortal sin, even if you bequeath your parts to others who need them in your will…er, suicide note…whatever. This movies epitomizes the culture of death. The advocates of euthanasia and the right-to-die movement undoubtedly loves the message. Ben (played by Will Smith) is praised for his generous gift of self, but any good Christian will tell you that it is a gift that he had no right to give.

The Time Traveler’s Wife (2009)

The Imaginarium of Doctor Parnassus (2009)

Never Let Me Go (2010)

Old Testament

New Testament