PRINTF()

_printf() - lightweight version of printf, supporting basic and most used functionality

Synopsis • Description • Format • Supported Functionality Work in Progress

Synopsis:

Main Includes:

• #include <unistd.h>
• #include <stdarg.h>

For Testing Includes:

• #include <stdio.h>
• #include <stdlib.h>
• #include <limits.h>
• #include <string.h>

Prototype:

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

Important information:

We are currently working on adding support for width, precision and length. To keep track of current funcionality pease review the Suported Functionalitysection.

Contributors:

• Carlon Bentin
• Cristhian Apaza

Description

The function _printf produce output according to a format described below, directed into stdout, the standard output stream. The _printf writes the output under the control of a format string that specifies how subsequent arguments are converted for output.

Format

The format string is a character string, beginning and ending in its initial shift state, if any. The format string is composed of zero or more directives: ordinary characters (not %), which are copied unchanged to the output stream; and conversion specifications, each of which results in fetching zero or more subequents arguments. Each conversion specification is introduced by the character %, and ends with a conversion specifier, like this:

% [FLAGS][width][.precision][length]specifier

example

_printf("Hello, %s. project took us %+d days, which in hexa is %#x\n", "World", 5, 5);

result:

Supported Functionality

Supported features:

FLAGS

Flag	Output	Syntaxis	Example
+	Adds + in front of output	("%+d", 250)	"+250"
space	Adds '_' in front of ouput	("% d", 250)	" 250"
#	Alters format to o, x or X. prefixes 0 for non 0 numbers	("%#x", 250)	"0xfa"

SPECIAL CASES:

CASE	Output	Syntaxis	Example
r	prints string in reverse	("%r", "ABC")	"CBA"
R	prints string encoded using ROT13	("%R", "ABC")	"NOP"

SPECIFIERS

Spec	Output	Syntaxis	Example
c	character	("%c", 'A')	"A"
s	String	("%s", "ABC")	"ABC"
d	Decimal	("%d", 250)	"250"
i	Integer	("%i", 250)	"250"
u	Unsigned Int	("%u", 250)	"250"
o	Octal	("%o", 250)	"372"
x	Hexadecimal (no caps)	("%x", 250)	"fa"
X	Hexadecimal (CAPS)	("%X", 250)	"FA"
b	Binary	("%b", 250)	"11111010"

Work n Progress

We are currently working on adding the following format options to the library:

• Adding to s - Print Non-printable characters as "\x" followed by ASCII code value in Upper Case Hexadecimal
• Adding [p] - Printing memory adress
• Adding length modifiers [l] [h]
• Adding width modifiers
• Adding precision modifiers
• Adding additional flags: [0], [-]

Contact Information

Please feel free to contact us regarding any matter (specially about mistakes, recomendations and gramar errors)

Cristhian Apaza -

Carlos Bentin -