C - printf project

An ALX Africa Software Engineering Program project.

Project Overview

This is a collaborative project to build a custom _printf function in C that simulates the standard printf function!

This project aims to enhance our understanding of C programming and explore the intricacies of building a fundamental yet powerful function used for formatted output.

Project Contributors

• Meet the amazing individuals contributing to this project:
  • @dahunsi-dami
  • @eveshogweyore

Technologies Used

• This project leverages the following technologies:
  • Programming Language: C
  • Operating System: Ubuntu 20.04

Functions Overview

We built several functions from scratch, each prefixed with an underscore _, to handle different aspects of the custom _printf functionality. The project leverages C's variadic functions and other advanced features, making it a rewarding learning experience.

Here is a table summarizing the key functions used in this project.

Functions we built from scratch start with the underscore _ character.

Function Name	Description
_printf	Produces output according to a specified format, handles special cases with _print_all, prints characters using _putchar, and returns the total number of characters printed (excluding the null byte).
_putchar	Writes a single character to the standard output, and returns 1 on success or -1 if an error occurs.
_print_all	Decides which argument to take in based on the specifier it encounters by calling appropriate helper functions (e.g., _print_s for strings, _dtob for binary), and returns the total number of characters printed or % if the specified is invalid, followed by the specifier itself.
_print_d	Prints an integer (including negative numbers) to the standard output, and returns the total number of characters printed.
_print_s	Prints a string minus null byte, or "(null)" if the string is NULL, to the standard output, and returns the total number of characters printed.
_add_to_buffer	Appends a specified character to a string buffer, updates its null terminator, and returns the new length of the string in the buffer.
_dtob	Converts a given decimal integer to its binary representation, prints it using _putchar, and returns the number of binary digits printed.
write	Writes a specified character with a specified size in bytes to a specified output.
va_start	Tells va_arg after which argument to start collecting variable arguments from.
va_end	Ends the process of taking in variable arguments.

Compilation

All files were compiled on Ubuntu 20.04 LTS using gcc with these options:

$ gcc -Wall -Werror -Wextra -pedantic -std=gnu89 *.c

Requirements

• All code uses the Betty style and is checked witih betty-style.pl and betty-doc.pl.
• No global variables were allowed or used.
• No more than 5 functions per file.
• All function prototypes are included in the header file called main.h.
• All header files are include guarded.