Description

This team project is part of the first year curriculum of ALX School. _printf replicates the C standard library printf() function.

What you should learn from this project:

• How to use git in a team setting
• Applying variadic functions to a big project
• The complexities of printf
• Managing a lot of files and finding a good workflow

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printf()

The printf project is a collaboration between Jonathan Abayie Boahene - Abayie and Degbor Johnson - jo-dev123, actual students of Software Engineering at ALX School, where a function named "_printf" imitates the actual "printf" command located in the stdio.h library. It contains some of the basic features and functions found in the manual 3 of "printf".

_printf() is a function that performs formatted output conversion and print data. Its prototype is the following:

int _printf(const char *format, ...)

Where format contains the string that is printed. As _printf() is variadic function, it can receives n arguments that replace by n tags written inside the string.

The format tags prototype is the following:

%[flags][length]specifier

If the program runs successfully, the return value is the amount of chars printed.

Specifier	Output
c	Character
d or i	Signed decimal integer
s	String of characters
b	Signed binary
o	Signed octal
u	Unsigned integer
x	Unsigned hexadecimal
X	Unsigned hexadecimal (uppercase)
p	Pointer address
r	Reverse string of characters
R	ROT13 translation of string
S	String with special chars replaced by their ASCII value
%	Character

Flags	Description	Specifiers
+	Prints a plus sign (+) when the argument is a positive number. In other case, prints a minus sign (-).	i, d
(space)	Prints a blank space if the argument is a positive number	i, d
#	Prints 0, 0x and 0X for o, x and X specifiers, respectively. It doesn't print anything if the argument is zero	o, x, X

Length	Description	Specifiers
l	Prints a long int or unsigned long int	i, d, o, u, x and X
h	Prints a short int or unsigned short int	i, d, o, u, x and X

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Usage

• Prints a string to the standard output, according to a given format
• All files were created and compiled on Ubuntu 20.04.4 LTS using GCC 9.3.0 with the command gcc -Wall -Werror -Wextra -pedantic *.c
• Returns the number of characters in the output string on success, -1 otherwise
• Call it this way: _printf("format string", arguments...) where format string can contain conversion specifiers and flags, along with regular characters

Examples

1. Printing the string of chars "Hello, Holberton":

   • Use: _printf("Hello Hol%s.", "berton");
   • Output: Hello Holberton.

2. Printing an integer number:

   • Use: _printf("10 + 10 is equal to %d.", 20);
   • Output: 10 + 10 is equal to 20.

3. Printing a binary, octal and hexadecimal:

   • Use: _printf("10 in binary is [%b], in octal is [%o] and in hexadecimal is [%x]", 5, 5, 5);
   • Output: 10 in binary is [1010], in octal is [12] and in hexadecimal is [A]

4. Printing a string codified in ROT13:

   • Use: _printf("Hello in ROT13 is %R", "Hello");
   • Output: Hello in ROT13 is Urybb

Using flags and length tags:

5. Printing the string of chars "Hello, Holberton":

   • Use: _printf("2 * 2 = %+d and 5 * -5 = %+i", 4, -25);
   • Output: 2 * 2 = +4 and 5 * -5 = -25

6. Printing a long integer number and short integer number:

   • Use: _printf("1 million as a long int is %ld, but as a short int is %hd", 1000000, 1000000);
   • Output: 1 million as a long int is 1000000, but as a short int is 16960

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File Functions

_printf.c

Own Printf Function That Performs Formatted Output Conversion And Print Data.

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main.h

Header File Where All Prototypes Are Saved.

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0. I'm not going anywhere. You can print that wherever you want to. I'm here and I'm a Spur for life

• Write a function that produces output according to format.
  • c : converts input into a character
  • s : converts input into a string

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1. Education is when you read the fine print. Experience is what you get if you don't

• Handle the following conversion specifiers:
  • d : converts input into a base 10 integer
  • i : converts input into an integer

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2. Just because it's in print doesn't mean it's the gospel

• Create a man page for your function

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3. With a face like mine, I do better in print

• Handle the following conversion specifiers:
  • b : the unsigned int argument is converted to binary

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4. What one has not experienced, one will never understand in print

• Handle the following conversion specifiers:
  • u : converts the input into an unsigned integer
  • o : converts the input into an octal number
  • x : converts the input into a hexadecimal number
  • X : converts the input into a hexadecimal number with capital letters

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5. Nothing in fine print is ever good news

• Use a local buffer of 1024 chars in order to call write as little as possible.

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6. My weakness is wearing too much leopard print

• Handle the following custom conversion specifier:
  • S : prints the string
  • Non printable characters (0 < ASCII value < 32 or >= 127) are printed this way: \x, followed by the ASCII code value in hexadecimal (upper case - always 2 characters)

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7. How is the world ruled and led to war? Diplomats lie to journalists and believe these lies when they see them in print

• Handle the following conversion specifier:
  • p : int input is converted to a pointer address

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8. The big print gives and the small print takes away

• Handle the following flag characters for non-custom conversion specifiers:
  • + : adds a + in front of signed positive numbers and a - in front of signed negative numbers
  • space : same as +, but adds a space (is overwritten by +)
  • # : adds a 0 in front of octal conversions that don't begin with one, and a 0x or 0X for x or X conversions

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[9. Sarcasm is lost in print]

• Handle the following length modifiers for non-custom conversion specifiers:
  • l : converts d, i, u, o, x, X conversions in short signed or unsigned ints
  • h : converts d, i, u, o, x, X conversions in long signed or unsigned ints

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[10. Print some money and give it to us for the rain forests]

• Handle the field width for non-custom conversion specifiers.

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[11. The negative is the equivalent of the composer's score, and the print the performance]

• Handle the precision for non-custom conversion specifiers.

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[12. It's depressing when you're still around and your albums are out of print]

• Handle the 0 flag character for non-custom conversion specifiers.

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[13. Every time that I wanted to give up, if I saw an interesting textile, print what ever, suddenly I would see a collection]

• Handle the - flag character for non-custom conversion specifiers.

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14. Print is the sharpest and the strongest weapon of our party

• Handle the following custom conversion specifier:
  • r : prints the reversed string

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15. The flood of print has turned reading into a process of gulping rather than savoring

• Handle the following custom conversion specifier:
  • R : prints the rot13'ed string

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[16. * ]

• All the above options work well together.

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Authors

Jonathan Abayie Boahene Abayie Degbor Johnson. jo-dev123

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End