0x07-pointers_arrays_strings

0x07-pointers Arrays Strings 0. memset Write a function that fills memory with a constant byte.

Prototype: char *_memset(char *s, char b, unsigned int n);
The _memset() function fills the first n bytes of the memory area pointed to by s with the constant byte b
Returns a pointer to the memory area s

1. memcpy Write a function that copies memory area.

   Prototype: char *_memcpy(char *dest, char *src, unsigned int n); The _memcpy() function copies n bytes from memory area src to memory area dest Returns a pointer to dest

2. strchr Write a function that locates a character in a string.

   Prototype: char *_strchr(char *s, char c); Returns a pointer to the first occurrence of the character c in the string s, or NULL if the character is not found

3. strspn Write a function that gets the length of a prefix substring.

   Prototype: unsigned int _strspn(char *s, char *accept); Returns the number of bytes in the initial segment of s which consist only of bytes from accept

4. strpbrk Write a function that searches a string for any of a set of bytes.

   Prototype: char *_strpbrk(char *s, char *accept); The _strpbrk() function locates the first occurrence in the string s of any of the bytes in the string accept Returns a pointer to the byte in s that matches one of the bytes in accept, or NULL if no such byte is found

5. strstr Write a function that locates a substring.

   Prototype: char *_strstr(char *haystack, char *needle); The _strstr() function finds the first occurrence of the substring needle in the string haystack. The terminating null bytes (\0) are not compared Returns a pointer to the beginning of the located substring, or NULL if the substring is not found.

6. Chess is mental torture Write a function that prints the chessboard.

7. The line of life is a ragged diagonal between duty and desire Write a function that prints the sum of the two diagonals of a square matrix of integers.

   Prototype: void print_diagsums(int *a, int size); Format: see example You are allowed to use the standard library

Note that in the following example we are casting an int[][] into an int*. This is not something you should do. The goal here is to make sure you understand how an array of array is stored in memory.

8. Double pointer, double fun Write a function that sets the value of a pointer to a char.