ft_printf

Implementing my own printf in C

Function

int ft_printf(const char *str, ...);

Capabilities

• %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

Pseudo Code

• Declare a va_list ptr
• Iterate through the first string
  • If we see % + format_char, we will access the next argument using va_arg and process it according to what the format_char is
    ex: as we iterate through the string, we come across %d. The next va_arg is "123". We will use ft_putnbr to print out the argument and count the approriate chars being printed
  • Otherwise we print the character
  • Don't forget to count the characters being printed out!
• va_end and return count

Concepts

Variadic functions: functions that can allow a variable number of arguments

1. va_list: declare this pointer type to use in the below functions
2. va_start: allow access to varaidac function arguments
   va_start(va_list ap, argN) va_list is the pointer to the last fixed arg in the variadic function
   argN is the last fixed argument n the variadic function
3. va_arg: access next argument
   va_arg(va_list ap, type) type is the type of of data that va_arg should expect
4. va_copy: make copy of function args
   va_copy(va_list dest, va_list src)
5. va_end: end traversal of function arguments va_end(va_list ap)