/printf

A personal clone of C printf function

Primary LanguageC

printf()

This printf project is a collaboration between Ayandiran I Temitope and Ajayi W Favour. This is an attempt to create our own printf function. Which will mimic the actual "printf" command located in the stdio.h library. It will contain some of the basic features and functions found in the manual 3 of "printf".

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

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

Where format contains the string that is printed. As _printf() isa variadic function, it can receive n arguments that will be replaced 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

Examples

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

    • Use: _printf("Hello W%s.", "orld");
    • Output: Hello World.

  2. Printing an integer number:

    • Use: _printf("100 + 100 is equal to %d.", 200);
    • Output: 100 + 100 is equal to 200.

  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:

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

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

  2. 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

Authors

Ayandiran I Temitope and Ajayi W Favour

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