In _printf project we code from zero our own custom printf function. Native printf function allows you to print with certain formats. We handle most basic format so you can print chars, strings, positive and negative numbers, hex, octa and binary numbers among other formats. You can see man 3 of printf to understand how printf works.
Compile
gcc -Wall -Werror -Wextra -pedantic *.c -o executable
Prototype
int _printf(const char *format, ...)
Return
If everything is successful, the function returns the num of chars printed.
Format conversion
| Format | Description |
|---|---|
| c | Print char values |
| s | Print strings |
| d, i | Print numbers [positive and negative] |
| b | Print nums converted to binary |
| u | Print nums as unsigned int |
| o | Print nums converted to octal |
| x | Print nums converted to hexa [uppercase] |
| X | Print nums converted to hexa [uppercase] |
| %% | Print % character |
| p | Print memory adress [pointers] |
| r | Print string in reverse |
| S | Print string and non-printable chars [\x + ASCII value in hexa] |
| R | Print in rot13 |
Examples
- Print char values
- Input
_printf("%c", 'x') - Output:
x - Input
_printf("%c", 97) - Output:
a
- Print strings
- Input
_printf("Hello%s\n", " Holberton!") - Output:
Hello Holberton!
- Print numbers
- Input
_printf("%d", 1024) - Output:
1024 - Input
_printf("%i", -2048) - Output:
-2048
- Print converted to binary
- Input
_printf("%b\n", 15) - Output:
1111
- Print as unsigned int
- Input
_printf("%u\n", 15) - Output:
15 - Input
_printf("%u\n", -15) - Output:
4294967281
- Print converted to octal
- Input
_printf("%o\n", 15) - Output:
17
- Print converted to hexa (lower and uppercase)
- Input
_printf("%x\n", 30) - Output:
1e - Input
_printf("%X\n", 30) - Output:
1E
- Print %
- Input
_printf("%%\n") - Output:
% - Input
_printf("%%-%%\n") - Output:
%-%
- Print memory adress [pointers]
- Input
_printf("%p\n", ptr) - Output:
0x7ffe637541f0
- Print string in reverse
- Input
_printf("Holberton - %r\n", "Holberton") - Output:
Holberton - notrebloH
- Print string and non-printable chars
- Input
_printf("%S\n", "Holberton\nSchool") - Output:
Holberton\x0ASchool
- Print in rot13
- Input
_printf("%R\n", "Holberton") - Output:
Ubyoregba
- Alert: Almost all functions, modify the buffer and returns it. (char *)
| File | Description |
|---|---|
| _itoa.c | Tools functions: rev_string: reverse a string passed as argument string_toupper: convert to uppercase string passed as argument _calloc: allocate memory and fills it with zeros _itoa: convert num to base and return as string (unsigned int) adress: convert num to base and return as string (long int) |
| _printf.c | Core of the project: _printf: 1. Start the variadic list 2. Retrieves dictonary and allocate buffer 3. Iterates string argument and check for %, if % found then check if the next char match with valid format, in that case call the respective function of these format. If after % there is other char of non-valid format saves in buffer %. If % and the next char is null, returns -1. If % not found, saves in buffer each character 4. When finish loop for string argument, prints all in buffer [print_buff] 5. Free all memory allocated |
| aux_funs.c | Firtst group advanced functions: print_b: add digits in base 2 to buffer print_u: add unsigned integers to buffer print_o: add digits in octal base to buffer print_x: add digits in hexadecimal base to buffer print_X: add digits in hexadecimal uppercase base to buffer |
| buff_funs.c | Print all chars saved in buffer: print_buff: print buffer with null at the end and free buffer memory |
| holberton.h | Header file: struct funs - filter: Used for dictonary Include all prototypes |
| man_3_printf | Man page of _printf function |
| print_funs.c | Basic functions: hand: Dictonary. Creates array of filter's for all valid formats print_c: add char to buffer print_str: add string to buffer print_d: print digits base 10 pr: add percentage to buffer |
| printf_advance.c | Second group advanced functions: print_p: add pointers - adress to buffer print_r: add string in reverse to buffer print_rot13 add string in rot13 to buffer print_S: add string and non-printable chars [\x + ASCII code] |
David Gonzalez - @davidgonzalezfx
Christian Bedoya - @chrisdav1022
Santiago Mendieta - @stostat