ft_printf

The goal of this project is pretty straightforward: to recode printf(). The projects is about learning variable numbber of arguments (variadic functions), as well as adding a couple more functions to the ft_libft.

Program name	libftprintf.a
Turn in files	Makefile, *.h, *.c, /.h, /.c
Makefile	NAME, all, clean, fclean, re and bonus (if done)
External functs	malloc, free, write, va_start, va_arg, va_copy, va_end
Libft authorized	Yes
Description	Write a library that contains ft_printf(), a function that will mimic the original printf()

• Mandatory part
  • Don’t implement the buffer management of the original printf().
  • Your function has to handle the following conversions: cspdiuxX%
  • Your function will be compared against the original printf().
  • You must use the command ar to create your library. Using the libtool command is forbidden.
  • Your libftprintf.a has to be created at the root of your repository.
  • You have to implement the following conversions:
    • %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.
• Bonus
  • Manage any combination of the following flags: ’-0.’ and the field minimum width under all conversions.
  • Manage all the following flags: ´#´ ´ ´ ´+´ (Yes, one of them is a space)

Note: if you plan to implement the bonus part, think abouut the impllementation of your extra features from the start. This way, youu will avoid the pitfalls of a naive approach.

How to use

1 - Clone the repository

git clone [email protected]:mxvements/ft_printf.git 

2 - Enter the project folder and run make, Makefile rules:

`make` - compile printf mandatory files
`make bonus` - compile printf bonus files
`make all` - compile all (mandatory + bonus) files
`make clean` - delete all *.o files
`make fclean` - delete all *.o & *.a (executable) files
`make re` - use fclean + all, recompile printf
`make tclean` - added rule, delete all *.o & clean *.out file from test

3 - To incluide it in your code, include the header

# include "ft_printf.h"

Notes

On the printf() specifiers and flags

1 - Specifiers and output

sp	ft_printf()	description
%c	√	character
%d or %i	√	signed decimal integer
%e		scientific noation (mantissa/exponent) using e char
%E		Scientific notation (mantissa/exponent) using E char
%f		decimal floating point
%g		uses the shorter of %e or %f
%G		uses the shorter of %E or %f
%o		signed octal
%s	√	string of characters
%u	√	unsigned decimal integer
%x	√	unsigned hexadecimal integer
%X	√	unsigned hexadecimal integer (capital letters)
%p	√	pointer address
%n		nothing printed
%	√	% char

2 - Flags and description

specifier	ft_printf()	description
+	√	forces to precede the result with a plus or minus sign (+ or -) even for positive numbers. By default, only negative numbers are preceded with a -ve sign.
(space)	√	if no sign is going to be written, a blank spcace is inserted before the value
#	√	%#o %#x %#X -> value precede with 0, 0x, 0X values != 0 / %#e %#E %#f -> forces to contain a decimal point even if no digits would follow / %#g %#G -> the same as w/ e or E, removing trailing 0
0		left-pads the number with zeros (0) instead of spaces, where padding is specified (see width sub-specifier)

On variadic functions

void va_start(va_list argument_list, last_known_parameter);

• DESCRIPTION : va_start() macro, intializes your argument_list for use by va_arg() and va_end(), and must be called first. The last_known_parameter is the name of the last known parameter of the calling function, here, ft_printf();

argument_type va_arg(va_list argument_list, argument_type)

• DESCRIPTON: everytime it is called, it modifies argument_list so that the next time is is called, it will return the next argument.
• RETURN VALUE: Expands to an expression that has the type and value of the next arg. in the call. The 1st use of the va_arg() macro after that of the va_start() macro returns the argument after last_known_parameter.
• NOTES: Successive invocations return the values of the remaining arguments. It is your job to make sure you're giving va_arg() the correct type of variable to return, it will assume you know what's being sent.

void va_end(va_list argument_list)

• DESCRIPTION: Each invocation of va_start() must be matched by a corresponding invocation of va_end() in the same function. After the call to va_end(), the variable argument_list is undefined.

Other

Norminete

At 42 School, it is expected that almost every project is written in accordance with the Norm, which is the coding standard of the school.

Norminette's repository

- No for, do...while, switch, case, goto, ternary operators and variable-length arrays are allowed
- Each function must be a maximum of 25 lines, not counting the function's curly brackets
- Each line must be at most 80 columns wide, comments included
- A function can take 4 named parameters maximum
- No assigns and declarations in the same line (unless static or const)
- You can't declare more than 5 variables per function
- ...

Aknowledgments

• This video by Nikito: https://www.youtube.com/watch?v=Hb2m7htiKWM

License

MIT License