0x0E-function_pointers

0x0E. C - Function pointers

0. What's my name mandatory

Write a function that prints a name.

• Prototype: void print_name(char *name, void (*f)(char *));

1. If you spend too much time thinking about a thing, you'll never get it done mandatory

Write a function that executes a function given as a parameter on each element of an array.

• Prototype: void array_iterator(int *array, size_t size, void (*action)(int));
• where size is the size of the array
• and action is a pointer to the function you need to use

2. To hell with circumstances; I create opportunities mandatory

Write a function that searches for an integer.

• Prototype: int int_index(int *array, int size, int (*cmp)(int));
• where size is the number of elements in the array array
• cmp is a pointer to the function to be used to compare values
• int_index returns the index of the first element for which the cmp function does not return 0
• If no element matches, return -1
• If size <= 0, return -1

3. A goal is not always meant to be reached, it often serves simply as something to aim at mandatory

Write a program that performs simple operations.

• You are allowed to use the standard library
• Usage: calc num1 operator num2
• The program prints the result of the operation, followed by a new line
• num1, num2 are integers. Use the atoi function to convert them to int
• operator is one of the following:
  • +: addition
  • -: subtraction
  • *: multiplication
  • /: division
  • %: modulo
• You can assume that the result of all operations can be stored in an int
• if the number of arguments is wrong, print Error, followed by a new line, and exit with the status 98
• if the operator is none of the above, print Error, followed by a new line, and exit with the status 99
• if the user tries to divide (/ or %) by 0, print Error, followed by a new line, and exit with the status 100

This task requires that you create four different files.

3-calc.h

This file should contain all the function prototypes and data structures used by the program. You can use this structure:

4. Most hackers are young because young people tend to be adaptable. As long as you remain adaptable, you can always be a good hacker #advanced

Write a program that prints the opcodes of its own main function.

• Usage: ./main number_of_bytes
• Output format:
  • the opcodes should be printed in hexadecimal, lowercase
  • each opcode is two char long
  • listing ends with a new line
  • see example
• You are allowed to use printf and atoi
• You have to use atoi to convert the argument to an int
• If the number of argument is not the correct one, print Error, followed by a new line, and exit with the status 1
• If the number of bytes is negative, print Error, followed by a new line, and exit with the status 2
• You do not have to compile with any flags

Note: if you want to translate your opcodes to assembly instructions, you can use, for instance udcli.