PRINT FORMATTED: _printf

Printf function project performed by Angela Vergara & Juan Bocanegra.

_printf is an emulation of the original printf that refers to a control parameter used by a class of functions in the input/output libraries of C.
A string is written, characters are usually copied literally into the function's output, but format specifier, which starts with a % character, indicate the location and method to translate a piece of data to characters or modifiers, starting with \ character, indicates inline modifiers such as tab or newline.

About this Repo

Requirments to built it

• Files should be compiled with gcc 4.8.4
• No more than 5 functions per file
• Files should end with a new line
• No global variables allowed

This project contains four C files, a header, and a man-page with all functions, prototypes, and descriptions you need to play with this version.

C files
_printf.c:
_printf : This function evaluates the string input characters one by one looking for matching characters with de modifiers % and / to call a function for each case if there is no coincidence just prints all strings without modifications.
*_printspecials : Search into a string of special modifiers to print the modifier (\n \t \b \f \v \r) or return the characters.
_printmod.c
pbuffer : Function that prints and delete chars in buffer.
p_intmin : Prints integers longer or equal than Min and Max integer limits.
p_int : Evaluates if the number is longer than integer limits and calls p-intmin otherwise prints integers calling _itoa _itoa : converts an integer number into a string
_printmod : Search into a structure of specifiers (%c, %s, %d, %i, %R, %,r %b, %o, %x, %X) a function to print a format input
_printcs.c
p_char : Prints a char.
p_string : Prints strings.
p_reverse : Prints strings in reverse.
p_rot13 : Encodes a string using rot13.
_printbases.c
p_binary : converts a number into binary
p_octal : converts a number into octal
p_hexalow : converts a number into hexdecimal lowercase
p_hexaup : converts a number into hexdecimal uppercase

Header
holberton.h: This file contains prototypes for all the functions and the struct for data and function relation.

Man-page
man_3_printf : Custom man page for _printf function.

To access the Man Page. man_3_printf directly in a terminal, download the file and move it to the directory /usr/share/man/man1 where the system stores man pages for User shell commands.
You can view it by typing the following command: cd /usr/share/man/man1 Otherwise into the project directory by typing ./man_3_printf ..

How to use this project

1. Please clone this repo into your sandbox or local terminal.
2. Access to the directory and compile all C files with the command: gcc -Wall -Wextra -Werror -pedantic -std=gnu89 -Wno-format *.c - o _printf ( _printf is a suggested name, not mandatory)
3. Typing ./_printf shows all cases set in the main.c file.
4. For another test, please modify the main.c file considering the man-page description.

Example of main.c file:

#include <limits.h> #include <stdio.h> #include "holberton.h"

/**

• main - Entry point

• Return: Always 0 */ int main(void) { int len; unsigned int ui; void *addr;

  len = _printf("Let's try to printf a simple sentence.\n");
  ui = (unsigned int)INT_MAX + 1024;
  addr = (void *)0x7ffe637541f0;
  _printf("Length:[%d, %i]\n", len, len);
  _printf("Negative:[%d]\n", -762534);
  _printf("Unsigned:[%u]\n", ui);
  _printf("Unsigned octal:[%o]\n", ui);
  _printf("Unsigned hexadecimal:[%x, %X]\n", ui, ui);
  _printf("Character:[%c]\n", 'H');
  _printf("String:[%s]\n", "I am a string !");
  _printf("Address:[%p]\n", addr);
  len = _printf("Percent:[%%]\n");
  _printf("Len:[%d]\n", len);
  _printf("Unknown:[%r]\n");
  return (0);
  }

Expected results after compiling and executing:

  Let's try to printf a simple sentence.
  Length:[39, 39]  
  Negative:[-762534]  
  Unsigned:[2147484671]  
  Unsigned octal:[20000001777]  
  Unsigned hexadecimal:[800003ff, 800003FF]  
  Character:[H]  
  String:[I am a string !]  
  Address:[0x7ffe637541f0]  
  Percent:[%]  
  Len:[12]  
  Unknown:[%r]  

Flowchart

This project was thought to compile previous concepts such as Loops, Structures, Functions, and Variadic functions. For better understanding you can access the logic behind the program as follows:

The core function is int _printf(const char * const format, ...) in the file _printf.c This function evaluates the string input characters one by one looking for matching characters with de modifiers % and / if there is no coincidence just prints all strings without modifications.