int printf(const char *fmt, ...)

/************************************************************************************
** File: - Z:\code\c\LLprintf\print2.1\LLprintf.c
**  
** Copyright (C), Long.Luo, All Rights Reserved!
** 
** Description: 
**      LLprintf.c
** 
** Version: 2.0
** Date created: 23:56:33,24/01/2013
** Author: Long.Luo
** 
** --------------------------- Revision History: --------------------------------
** 	<author>	<data>			<desc>
** 
************************************************************************************/

 
#include "LLprintf.h"


// Lprintf
int Lprintf(const char *fmt, ...)
{
	int i;
	char buf[256];

	va_list arg = (va_list)((char*)(&fmt) + 4); /*4是参数fmt所占堆栈中的大小*/
	i = vsLprintf(buf, fmt, arg);
	buf[i] = 0;
	LLprint(buf, i);

	return i;
}

va_list arg = (va_list)((char*)(&fmt) + 4); 

typedef char *va_list

i = vsLprintf(buf, fmt, arg);

int vsLprintf(char *buf, const char *fmt, va_list args)
{
	char *p;
	int	m;
	char inner_buf[STR_DEFAULT_LEN];
	char cs;
	int	align_nr;
	
	va_list	p_next_arg = args;

	for (p=buf; *fmt; fmt++) {
		if (*fmt != '%') {
			*p++ = *fmt;
			continue;
		}
		else {		/* a format string begins */
			align_nr = 0;
		}

		fmt++;

		if (*fmt == '%') {
			*p++ = *fmt;
			continue;
		}
		else if (*fmt == '0') {
			cs = '0';
			fmt++;
		}
		else {
			cs = ' ';
		}
		while (((unsigned char)(*fmt) >= '0') && ((unsigned char)(*fmt) <= '9')) {
			align_nr *= 10;
			align_nr += *fmt - '0';
			fmt++;
		}

		char * q = inner_buf;
		memset(q, 0, sizeof(inner_buf));

		switch (*fmt) {
		case 'c':
			*q++ = *((char*)p_next_arg);
			p_next_arg += 4;
			break;
		case 'x':
			m = *((int*)p_next_arg);
			i2a(m, 16, &q);
			p_next_arg += 4;
			break;
		case 'd':
			m = *((int*)p_next_arg);
			if (m < 0) {
				m = m * (-1);
				*q++ = '-';
			}
			i2a(m, 10, &q);
			p_next_arg += 4;
			break;
		case 's':
			strcpy(q, (*((char**)p_next_arg)));
			q += strlen(*((char**)p_next_arg));
			p_next_arg += 4;
			break;
		default:
			break;
		}

		int k;
		for (k = 0; k < ((align_nr > strlen(inner_buf)) ? (align_nr - strlen(inner_buf)) : 0); k++) {
			*p++ = cs;
		}
		q = inner_buf;
		while (*q) {
			*p++ = *q++;
		}
	}

	*p = 0;

	return (p - buf);
}

//*****************************************************************************
//
//! A simple UART based printf function supporting \%c, \%d, \%p, \%s, \%u,
//! \%x, and \%X.
//!
//! \param pcString is the format string.
//! \param ... are the optional arguments, which depend on the contents of the
//! format string.
//!
//! This function is very similar to the C library <tt>fprintf()</tt> function.
//! All of its output will be sent to the UART.  Only the following formatting
//! characters are supported:
//!
//! - \%c to print a character
//! - \%d to print a decimal value
//! - \%s to print a string
//! - \%u to print an unsigned decimal value
//! - \%x to print a hexadecimal value using lower case letters
//! - \%X to print a hexadecimal value using lower case letters (not upper case
//! letters as would typically be used)
//! - \%p to print a pointer as a hexadecimal value
//! - \%\% to print out a \% character
//!
//! For \%s, \%d, \%u, \%p, \%x, and \%X, an optional number may reside
//! between the \% and the format character, which specifies the minimum number
//! of characters to use for that value; if preceded by a 0 then the extra
//! characters will be filled with zeros instead of spaces.  For example,
//! ``\%8d'' will use eight characters to print the decimal value with spaces
//! added to reach eight; ``\%08d'' will use eight characters as well but will
//! add zeroes instead of spaces.
//!
//! The type of the arguments after \e pcString must match the requirements of
//! the format string.  For example, if an integer was passed where a string
//! was expected, an error of some kind will most likely occur.
//!
//! \return None.
//
//*****************************************************************************
void
UARTprintf(const char *pcString, ...)
{
    unsigned long ulIdx, ulValue, ulPos, ulCount, ulBase, ulNeg;
    char *pcStr, pcBuf[16], cFill;
    va_list vaArgP;

    //
    // Check the arguments.
    //
    ASSERT(pcString != 0);

    //
    // Start the varargs processing.
    //
    va_start(vaArgP, pcString);

    //
    // Loop while there are more characters in the string.
    //
    while(*pcString)
    {
        //
        // Find the first non-% character, or the end of the string.
        //
        for(ulIdx = 0; (pcString[ulIdx] != '%') && (pcString[ulIdx] != '\0');
            ulIdx++)
        {
        }

        //
        // Write this portion of the string.
        //
        UARTwrite(pcString, ulIdx);

        //
        // Skip the portion of the string that was written.
        //
        pcString += ulIdx;

        //
        // See if the next character is a %.
        //
        if(*pcString == '%')
        {
            //
            // Skip the %.
            //
            pcString++;

            //
            // Set the digit count to zero, and the fill character to space
            // (i.e. to the defaults).
            //
            ulCount = 0;
            cFill = ' ';

            //
            // It may be necessary to get back here to process more characters.
            // Goto's aren't pretty, but effective.  I feel extremely dirty for
            // using not one but two of the beasts.
            //
again:

            //
            // Determine how to handle the next character.
            //
            switch(*pcString++)
            {
                //
                // Handle the digit characters.
                //
                case '0':
                case '1':
                case '2':
                case '3':
                case '4':
                case '5':
                case '6':
                case '7':
                case '8':
                case '9':
                {
                    //
                    // If this is a zero, and it is the first digit, then the
                    // fill character is a zero instead of a space.
                    //
                    if((pcString[-1] == '0') && (ulCount == 0))
                    {
                        cFill = '0';
                    }

                    //
                    // Update the digit count.
                    //
                    ulCount *= 10;
                    ulCount += pcString[-1] - '0';

                    //
                    // Get the next character.
                    //
                    goto again;
                }

                //
                // Handle the %c command.
                //
                case 'c':
                {
                    //
                    // Get the value from the varargs.
                    //
                    ulValue = va_arg(vaArgP, unsigned long);

                    //
                    // Print out the character.
                    //
                    UARTwrite((char *)&ulValue, 1);

                    //
                    // This command has been handled.
                    //
                    break;
                }

                //
                // Handle the %d command.
                //
                case 'd':
                {
                    //
                    // Get the value from the varargs.
                    //
                    ulValue = va_arg(vaArgP, unsigned long);

                    //
                    // Reset the buffer position.
                    //
                    ulPos = 0;

                    //
                    // If the value is negative, make it positive and indicate
                    // that a minus sign is needed.
                    //
                    if((long)ulValue < 0)
                    {
                        //
                        // Make the value positive.
                        //
                        ulValue = -(long)ulValue;

                        //
                        // Indicate that the value is negative.
                        //
                        ulNeg = 1;
                    }
                    else
                    {
                        //
                        // Indicate that the value is positive so that a minus
                        // sign isn't inserted.
                        //
                        ulNeg = 0;
                    }

                    //
                    // Set the base to 10.
                    //
                    ulBase = 10;

                    //
                    // Convert the value to ASCII.
                    //
                    goto convert;
                }

                //
                // Handle the %s command.
                //
                case 's':
                {
                    //
                    // Get the string pointer from the varargs.
                    //
                    pcStr = va_arg(vaArgP, char *);

                    //
                    // Determine the length of the string.
                    //
                    for(ulIdx = 0; pcStr[ulIdx] != '\0'; ulIdx++)
                    {
                    }

                    //
                    // Write the string.
                    //
                    UARTwrite(pcStr, ulIdx);

                    //
                    // Write any required padding spaces
                    //
                    if(ulCount > ulIdx)
                    {
                        ulCount -= ulIdx;
                        while(ulCount--)
                        {
                            UARTwrite(" ", 1);
                        }
                    }
                    //
                    // This command has been handled.
                    //
                    break;
                }

                //
                // Handle the %u command.
                //
                case 'u':
                {
                    //
                    // Get the value from the varargs.
                    //
                    ulValue = va_arg(vaArgP, unsigned long);

                    //
                    // Reset the buffer position.
                    //
                    ulPos = 0;

                    //
                    // Set the base to 10.
                    //
                    ulBase = 10;

                    //
                    // Indicate that the value is positive so that a minus sign
                    // isn't inserted.
                    //
                    ulNeg = 0;

                    //
                    // Convert the value to ASCII.
                    //
                    goto convert;
                }

                //
                // Handle the %x and %X commands.  Note that they are treated
                // identically; i.e. %X will use lower case letters for a-f
                // instead of the upper case letters is should use.  We also
                // alias %p to %x.
                //
                case 'x':
                case 'X':
                case 'p':
                {
                    //
                    // Get the value from the varargs.
                    //
                    ulValue = va_arg(vaArgP, unsigned long);

                    //
                    // Reset the buffer position.
                    //
                    ulPos = 0;

                    //
                    // Set the base to 16.
                    //
                    ulBase = 16;

                    //
                    // Indicate that the value is positive so that a minus sign
                    // isn't inserted.
                    //
                    ulNeg = 0;

                    //
                    // Determine the number of digits in the string version of
                    // the value.
                    //
convert:
                    for(ulIdx = 1;
                        (((ulIdx * ulBase) <= ulValue) &&
                         (((ulIdx * ulBase) / ulBase) == ulIdx));
                        ulIdx *= ulBase, ulCount--)
                    {
                    }

                    //
                    // If the value is negative, reduce the count of padding
                    // characters needed.
                    //
                    if(ulNeg)
                    {
                        ulCount--;
                    }

                    //
                    // If the value is negative and the value is padded with
                    // zeros, then place the minus sign before the padding.
                    //
                    if(ulNeg && (cFill == '0'))
                    {
                        //
                        // Place the minus sign in the output buffer.
                        //
                        pcBuf[ulPos++] = '-';

                        //
                        // The minus sign has been placed, so turn off the
                        // negative flag.
                        //
                        ulNeg = 0;
                    }

                    //
                    // Provide additional padding at the beginning of the
                    // string conversion if needed.
                    //
                    if((ulCount > 1) && (ulCount < 16))
                    {
                        for(ulCount--; ulCount; ulCount--)
                        {
                            pcBuf[ulPos++] = cFill;
                        }
                    }

                    //
                    // If the value is negative, then place the minus sign
                    // before the number.
                    //
                    if(ulNeg)
                    {
                        //
                        // Place the minus sign in the output buffer.
                        //
                        pcBuf[ulPos++] = '-';
                    }

                    //
                    // Convert the value into a string.
                    //
                    for(; ulIdx; ulIdx /= ulBase)
                    {
                        pcBuf[ulPos++] = g_pcHex[(ulValue / ulIdx) % ulBase];
                    }

                    //
                    // Write the string.
                    //
                    UARTwrite(pcBuf, ulPos);

                    //
                    // This command has been handled.
                    //
                    break;
                }

                //
                // Handle the %% command.
                //
                case '%':
                {
                    //
                    // Simply write a single %.
                    //
                    UARTwrite(pcString - 1, 1);

                    //
                    // This command has been handled.
                    //
                    break;
                }

                //
                // Handle all other commands.
                //
                default:
                {
                    //
                    // Indicate an error.
                    //
                    UARTwrite("ERROR", 5);

                    //
                    // This command has been handled.
                    //
                    break;
                }
            }
        }
    }

    //
    // End the varargs processing.
    //
    va_end(vaArgP);
}

/************************************************************************************
** File: - Z:\code\c\LLprintf\print2.1\app.c
**  
** Copyright (C), Long.Luo, All Rights Reserved!
** 
** Description: 
**      app.c --- The Application Level.
** 
** Version: 2.1
** Date created: 23:53:41,24/01/2013
** Author: Long.Luo
** 
** --------------------------- Revision History: --------------------------------
** 	<author>	<data>			<desc>
** 
************************************************************************************/

#include "LLprintf.h"

int main(void)
{
	char *welcome = "     A Tiny Demo show the LLprintf   ";
	char *program_name = "LLprintf";
	char *program_author = "Long.Luo";
	char *date = "Jan. 24th, 2013";
	
	float program_version = 2.1;
	
	Lprintf("%s\n\n", welcome);
	Lprintf("\t\t%s, version %f \n\n", program_name, program_version);
	Lprintf("\tCreated by %s, %s.\n\n", program_author, date);
	
	return 0;
}