My own printf function

• %c Prints a single character.
• %s Prints a string (as defined by the common C convention).
• %p The void * pointer argument has to be printed in hexadecimal format.
• %d Prints a decimal (base 10) number.
• %i Prints an integer in base 10.
• %u Prints an unsigned decimal (base 10) number.
• %x Prints a number in hexadecimal (base 16) lowercase format.
• %X Prints a number in hexadecimal (base 16) uppercase format.
• %% Prints a percent sign.