libftprintf de mfaussur 🇫🇷🇪🇺🌍

Reproduction of official apple's closed-source printf used in MacOS 10.13, with 64-bits integers, 80-bits floating points, undefined behaviours, and a new %b specifier designed to work with binary data so easily (cf. notes). Also implementation speed was not a goal, priority was more in code clarity, extensibility and limit-less inputs (I rely on RAM instead of a hard-coded limited string in the CPU cache, cf. Linus Torvalds's printf). This project targets the AINSI C99 specification.

primitives

• unistd.h    read()   write()
• stdlib.h    malloc()   free()
• stdargs.h    va_*()

extensibility

• register a specifier simply before calling your printf using ft_register_specifier()
• delete a specifier simply before calling your printf using ft_delete_specifier()

Both funtions rely on AT_EXIT=1 (cf. notes).

notes

• use %b to work with binary data using a pointer. This specifier is obviously compatible with regular precision / padding attributes.

long double x;

x = 1;
ft_printf("%#b", sizeof(long double), &x)
->  01101000 11001010 01101011 10111111 00011000 10100100 00111111 11111111 10000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000

For regular types, you can also use the regular qualifiers.

size_t x;

x = 1;
ft_printf("%zb", &x)
->  00000000 00000000 00000000 00000001

• gcc ... -D AT_EXIT=1 ... compilation flag will enable the use of a global variable for storing specifier to callback associations, this global variable will then be freed at exit, using stdlib.h's atexit().
• gcc ... -D LDMAXPRECISION=1024 ... compilation will modify the max precision that printf will support when handling long doubles.
• all functions that exist with a larger type will use the one with a larger type for avoiding repetitions.
• %Lf is different from original %Lf flag under macos when the decimal part of a long double exeeds 16-18 digits.
• %ls and %lc dont support unicode after a setlocale() because we are not allowed to rely on it (cf. primitives), so I use the default behaviour and I dont rely on any utf conversion. No garbage in - garbage out.

coming soon

• %e
• %a
• %g