ft_printf

This project was made in accordance with the project of School 21 (Ecole 42).

Preamble · Description · Examples · Installation and usage · Testing

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Preamble

The purpose of this project is to recode printf function in c.

You can see the subject here: ft_printf.

Main requirements, rules and code style: Norm.

The libft subdirectory is another project for School 21: Libft.

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Description

• The printf() function produces output according to a format as described below.
  The format string is a character string, beginning and ending in its initial shift state, if any.
  The format string is composed of zero or more directives: ordinary characters (not %), which
  are copied unchanged to the output stream; and conversion specifications, each of which results
  in fetching zero or more subsequent arguments. Each conversion specification is introduced by
  the character %, and ends with a conversion specifier. In between there may be (in this order)
  zero or more flags, an optional minimum field width, an optional precision and an optional length modifier.

• The overall syntax of a conversion specification is:
  %[flags][width][.precision][length modifier][conversion]

Mandatory part

ft_printf() must process following type specifiers:

1. %c - single character

2. %s - string of characters

3. %p - pointer to void (in hexadecimal)

4. %d - decimal number

5. %i - integer number

6. %u - unsigned decimal number

7. %x - number in hexadecimal (lowercase)

8. %X - number in hexadecimal (uppercase)

9. %% - percent character

Bonus part

ft_printf() must manage following format specifiers and minimum field width in any combination:

1. - - left-justify within the given field width, right justification is the default

2. 0 - left-pads the number with zeroes instead of spaces, where padding is specified

3. . - precision (is used with numeric values)

4. # - adding prefix 0x or 0X for %x or %X type specifiers respectively

5. + - adding sign (+ or -) in dependency of output value. By default shows only - sign
   for negative values

6. (space) - adding space before positive output values. By default shows only - sign
   for negative values. Ignored if both + and flags are used

• Also you can use width specifier (number) to define the field width.

• Width and precision specifiers can be presented due to * character.
  In this case * should be printed in formatting string for ft_printf at required position instead of
  numeric value. At the same time value for * is passed as argument.

• For futher information about printf() read the manual or wiki.

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Examples

• _ is showing spaces in output.

Command	Output
ft_printf("%3d", 1)	__1
ft_printf("%3d", 123456789)	123456789
ft_printf("%3d", -1)	_-1
ft_printf("%-3d", 1)	1__
ft_printf("%-3d", 123456789)	123456789
ft_printf("%-3d", -1)	-1_
ft_printf("%03d", 1)	001
ft_printf("%03d", 123456789)	123456789
ft_printf("%03d", -1)	-01
ft_printf("%+5d", 10)	__+10
ft_printf("%-+5d", 10)	+10__
ft_printf("%s", "Hello")	Hello
ft_printf("%10s", "Hello")	_____Hello
ft_printf("%-10s", "Hello")	Hello_____

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Installation and usage

Makefile compiles given functions into C static library file.

Compiler: gcc

Flags: -Wall -Werror -Wextra

• Go to the project folder:

$ cd 'path_to_ft_printf'

• Then typo one of these command:

Command	Description
make	compiling mandatory and bonus part
make bonus	compiling mandatory and bonus part
make clean	clearing all .o files
make fclean	clearing all .o files and library

• As you can see make and make bonus have the same behavior.

• To use compiled project in your code just include library header:

#include "ft_printf.h"

• While compiling your code add these flags:

-lft -L 'path_to_libftprintf.a' -I 'path_to_ft_printf.h'

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Testing

• You can check code norm due to norminette.

• These are some testers for ft_printf project:

  • printfTester

  • PFT

  • ftprintfdestructor