The following guidelines are expected for all homework submissions:

• All homework must be typed. Homework which is not typed will be returned ungraded and will be subject to the late homework guidelines as set out on the syllabus page. PLEASE DO NOT scribble something on lined paper and rip it out of your spiral notebook — hanging chads went out with the presidential election in 2000.
• I don't care too much about what font you use or how large your margins are; however, you might want to check out a monospaced font for typing code, as it will be easy to see the indentations.
• Speaking of indenting, PLEASE DON'T USE TABS TO INDENT YOUR CODE. Tabs can often get interpreted differently by different computers and applications, and could make code that is nicely formatted on your computer look all over the map on my computer or printer. USE SPACES INSTEAD. You can set up almost every modern text editor to insert spaces whenever you press the TAB key, or you can simply pound the spacebar.
• Work with a group. I can't stress this enough; part of this policy is don't split up the work – WORK TOGETHER on the assignment! DO NOT DIVIDE UP THE WORK!. Doing assignments this way mimics an industry code development model called pair programming which is part of the Extreme Programming [Agile] software development method. Agile teams are prevalent in the industry now, so feel free to collaborate in your groups as much as you want, doing the entire assignment together. Only submit ONE copy for the group.
• DO NOT SHARE YOUR WORK BETWEEN GROUPS. Doing so will count as plagiarism. If you wish to discuss solutions with another group over coffee in the Lair, that's fine as long as it is kept at the conceptual and you don't share your code between groups. Each group needs to turn in its own unique version of the solutions.
• Repeat: you only need to turn in one copy per group.
• Submit your homework through GitHub, in your repository, and be sure to make me a contributor so I have access. I cannot evaluate what I cannot see! If I can't upload to your repo, you will not get an evaluation for the assignment.

Problems for Assignment #5

Learning Outcomes: 1) writing programs using the C language; 2) handling string, integer, and binary representations; 3) understanding the change between 32-bit and 64-bit representations; 4) converting from decimal to binary/hexadecimal and back; and 5) learning to use the command line arguments

1. Write a C program, dec2bin.c to convert a base-10 number to its 32-bit binary value equivalent. You may take the base-10 number in from the command line, or you may prompt the user for the number and read in her response [your option]. Your output should be a string of binary digits which correspond to the base-10 value. For example, running the program with dec2bin 65535 [or just dec2bin if asking the user] should produce the output string 00000000000000001111111111111111. Use unsigned integers.
2. Modify your C program from problem #1 to to make the program dec2hex.c which will output the 32-bit or 64-bit [8-digit or 16-digit] hexidecimal equivalent of its input. For this modification, you must also handle an optional command line argument which indicates the number of digits the output hex value will contain, either 8 or 16. This will be the second argument on the line and if it is omitted the program will default to 32. For example, running the program with dec2hex 65535 8 should produce the output string 0x0000FFFF, and dec2hex 65535 16 should result in the output string 0x000000000000FFFF. If asking the user for input, both values should be asked for. Use unsigned integers.
3. Write a C program timesTables.cto output the times tables from 2 to N, where N is a user-defined number take from the command line. Output the values in a nice table, using a format specifier that will allow for enough space for the results to be neatly aligned in columns.
4. Write a C program holdit.c that times you as you hold your breath. The program must put out a short message that has instructions on what to do, which should read something like,
   "This program will time how long you can hold your breath. Take a deep breath, then press the 'Enter' key. When you absolutely have to exhale, press the enter key again. The duration will be displayed in minutes and seconds."
   You will need to research the way the time functions work in C.
5. Write a C program wordcount.c that counts the number of words in a file of text. Your program should take a file name as a command line argument. As you read the file contents, keep a count of the number of words which are separated by "whitespace". [Research what is meant by "whitespace" in the C environment.] When the file has been completely read, close the file and write out the number of words. Be sure you handle error conditions like files that don't exist or errors while reading the file. You should also be able to handle files that are in different directories from where your program resides.