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##Important Instructions

Please preserve the structure of this file, as it will subjected to partial automatic analysis. Only insert your answers by replacing the text YOUR ANSWER HERE; do not delete anything else.

Please use markdown formating to typeset code and Unix commands with the backtick character, for example, ls -la, or if you want to write code blocks, each line should be indented with four spaces, as done in the code below:

#include <stdio.h>

int main(void) {
	printf("Hello, world!\n");
	return 0;
}

##Exercises from the online Unix tutorial

###Exercise 1a

Make another directory inside the unixstuff directory called backups

Answer: YOUR ANSWER HERE

###Exercise 1b

Use the commands cd, ls and pwd to explore the file system.

(Remember, if you get lost, type cd by itself to return to your home-directory)

Answer: YOUR ANSWER HERE

###Exercise 2a

Create a backup of your science.txt file by copying it to a file called science.bak

Answer: YOUR ANSWER HERE

###Exercise 2b

Create a directory called tempstuff using mkdir, then remove it using the rmdir command.

Answer: YOUR ANSWER HERE

###Exercise 3a

Using the above method, create another file called list2 containing the following fruit: orange, plum, mango, grapefruit. Read the contents of list2.

Answer: YOUR ANSWER HERE

###Exercise 3b

Using pipes, display all lines of list1 and list2 containing the letter 'p', and sort the result.

Answer: YOUR ANSWER HERE

###Exercise 5a

Try changing access permissions on the file science.txt and on the directory backups.

Use ls -l to check that the permissions have changed.

Answer: YOUR ANSWER HERE

##Shell questions

  1. What option with the command rm is required to remove a directory?
  • Answer: YOUR ANSWER HERE
  1. What is the command used to display the manual pages for any command?
  • Answer: YOUR ANSWER HERE
  1. What command will show the first 5 lines of an input file?
  • Answer: YOUR ANSWER HERE
  1. What command can be used to rename a file?
  • Answer: YOUR ANSWER HERE
  1. What option can we given to ls to show the hidden files?
  • Answer: YOUR ANSWER HERE
  1. What will the command cat -n file do?
  • Answer: YOUR ANSWER HERE
  1. What will the command echo -n hello do?
  • Answer: YOUR ANSWER HERE
  1. What command will display s list of the users who currently logged in in the system?
  • Answer: YOUR ANSWER HERE
  1. How do you change password on your account?
  • Answer: YOUR ANSWER HERE
  1. How can you list a file in reverse order?
  • Answer: YOUR ANSWER HERE
  1. What does the less command do?
  • Answer: YOUR ANSWER HERE
  1. With less how do you navigate?
  • Answer: YOUR ANSWER HERE
  1. What command will display the running processes of the current user?
  • Answer: YOUR ANSWER HERE
  1. What command can be used to find the process(es) consuming the most CPU?
  • Answer: YOUR ANSWER HERE

##vi questions

  1. How do we save a file in vi and continue working?
  • Answer: YOUR ANSWER HERE
  1. What command/key is used to start entering text?
  • Answer: YOUR ANSWER HERE
  1. What are the different modes the editor can be in?
  • Answer: YOUR ANSWER HERE
  1. What command can be used to place the cursor at the beginning of line 4?
  • Answer: YOUR ANSWER HERE
  1. What will dd command do (in command-mode)?
  • Answer: YOUR ANSWER HERE
  1. How do you undo the most recent changes?
  • Answer: YOUR ANSWER HERE
  1. How do you move back one word?
  • Answer: YOUR ANSWER HERE

##The C Language and Make tool Questions

  1. How do you use gcc to only produce the .o file? What is the difference between generating only the .o file, and building the hello executable done in the previous compilation above?
  • Answer: YOUR ANSWER HERE
  1. Give the command for compiling with debug enabled instead of normal compilation for the two examples shown in Listing 2 and Listing 3. Explain how to turn debugging on/off for the two cases.
  • Answer: YOUR ANSWER HERE
  1. Give a brief pros and cons discussion for the two methods to add debug code shown in Listing 2 and Listing 3.
  • Answer: YOUR ANSWER HERE
  1. Provide the command for generating the map file. Which of the gcc tools is responsible for producing a map file?
  • Answer: YOUR ANSWER HERE
  1. What is the content of each of the sections in a map file. Explain briefly.
  • Answer: YOUR ANSWER HERE
  1. Rewrite hello.c to produce entries in the map file for .data, .bss, and .rodata. Hint: This can be done by adding one variable for each type to the file.
  • Answer: YOUR ANSWER HERE
  1. Add the following function to hello.c: double multiply(double x1, double x2), which returns x1*x2. Use gcc to generate an assembly code listing for the program, and examine the assembly code. What assembly instructions are used to do this? Repeat this task, but now replace double with float. Explain!
  • Answer: YOUR ANSWER HERE
  1. How does make know if a file must be recompiled?
  • Answer: YOUR ANSWER HERE
  1. Provide a make command to use a file named mymakefile instead of the default makefile.
  • Answer: YOUR ANSWER HERE
  1. How do you implement an include guard, and why is it needed?
  • Answer: YOUR ANSWER HERE

##Library Task

Insert your code between the brackets {}:

void main( int argc, char *argv[] )
{
}

double tab_sort_sum( double *tab, int tab_size )
{
}