0x06-pointers_arrays_strings

           0x06. C - More pointers, arrays and strings Task

1. 0-strcat.c Task: Write a function that concatenates two strings.

• Prototype: char *_strcat(char *dest, char *src);
• This function appends the src string to the dest string, overwriting the terminating null byte (\0) at the end of dest, and then adds a terminating null byte
• Returns a pointer to the resulting string dest

2. 1-strncat.c Task: Write a function that concatenates two strings.

• Prototype: char *_strncat(char *dest, char *src, int n);
• The _strncat function is similar to the _strcat function, except that it will use at most n bytes from src; and src does not need to be null-terminated if it contains n or more bytes
• Return a pointer to the resulting string dest

3. 2-strncpy.c Task: Write a function that copies a string.

• Prototype: char *_strncpy(char *dest, char *src, int n);
• Your function should work exactly like strncpy

4. 3-strcmp.c Task: Write a function that compares two strings.

• Prototype: int _strcmp(char *s1, char *s2);
• Your function should work exactly like strcmp

5. 4-rev_array.c Task: Write a function that reverses the content of an array of integers.

• Prototype: void reverse_array(int *a, int n);
• Where n is the number of elements of the array

6. 5-string_toupper.c Task: Write a function that changes all lowercase letters of a string to uppercase.

• Prototype: char *string_toupper(char *);

7. 6-cap_string.c Task: Write a function that capitalizes all words of a string.

Prototype: char *cap_string(char *); Separators of words: space, tabulation, new line, ,, ;, ., !, ?, ", (, ), {, and }

8. 7-leet.c Task: Write a function that encodes a string into 1337.

• Letters a and A should be replaced by 4
• Letters e and E should be replaced by 3
• Letters o and O should be replaced by 0
• Letters t and T should be replaced by 7
• Letters l and L should be replaced by 1
• Prototype: char *leet(char *);
• You can only use one if in your code
• You can only use two loops in your code
• You are not allowed to use switch
• You are not allowed to use any ternary operation

9. 100-rot13.c Task: Write a function that encodes a string using rot13.

• Prototype: char *rot13(char *);
• You can only use if statement once in your code
• You can only use two loops in your code
• You are not allowed to use switch
• You are not allowed to use any ternary operation

10. 101-print_number.c Task: Write a function that prints an integer.

• Prototype: void print_number(int n);
• You can only use _putchar function to print
• You are not allowed to use long
• You are not allowed to use arrays or pointers
• You are not allowed to hard-code special values

11. 102-magic.c Task: Add one line to this code, so that the program prints a[2] = 98, followed by a new line.

• You are not allowed to use the variable a in your new line of code
• You are not allowed to modify the variable p
• You can only write one statement
• You are not allowed to use ,
• You are not allowed to code anything else than the line of expected line of code at the expected line
• Your code should be written at line 19, before the ;
• Do not remove anything from the initial code (not even the comments)
• and don’t change anything but the line of code you are adding (don’t change the spaces to tabs!)
• You are allowed to use the standard library

12. 103-infinite_add.c Task: Write a function that adds two numbers.

• Prototype: char *infinite_add(char *n1, char *n2, char *r, int size_r);
• Where n1 and n2 are the two numbers
• r is the buffer that the function will use to store the result
• size_r is the buffer size
• The function returns a pointer to the result
• You can assume that you will always get positive numbers, or 0
• You can assume that there will be only digits in the strings n1 and n2
• n1 and n2 will never be empty
• If the result can not be stored in r the function must return 0

13. 104-print_buffer.c Task: Write a function that prints a buffer.

• Prototype: void print_buffer(char *b, int size);
• The function must print the content of size bytes of the buffer pointed by b
• The output should print 10 bytes per line
• Each line starts with the position of the first byte of the line in hexadecimal (8 chars), starting with 0
• Each line shows the hexadecimal content (2 chars) of the buffer, 2 bytes at a time, separated by a space
• Each line shows the content of the buffer. If the byte is a printable character, print the letter, if not, print .
• Each line ends with a new line \n
• If size is 0 or less, the output should be a new line only \n
• You are allowed to use the standard library
• The output should look like the following example, and formatted exactly the same way: