/*-----------------------------------------------------------------
    printfl.c - source file for reduced version of printf 
                
    Written By - Sandeep Dutta . sandeep.dutta@usa.net (1999)

    This program is free software; you can redistribute it and/or modify it
    under the terms of the GNU General Public License as published by the
    Free Software Foundation; either version 2, or (at your option) any
    later version.
    
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.
    
    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
    
    In other words, you are welcome to use, share and improve this program.
    You are forbidden to forbid anyone else to use, share and improve
    what you give them.   Help stamp out software-hoarding!  
-------------------------------------------------------------------------*/

/* following formats are supported :-
   format     output type       argument-type
     %d        decimal             int
     %ld       decimal             long 
     %hd       decimal             short/char
     %x        hexadecimal         int
     %lx       hexadecimal         long 
     %hx       hexadecimal         short/char
     %o        octal               int
     %lo       octal               long 
     %ho       octal               short/char
     %c        character           char/short
     %s        character           _generic pointer
*/

#include <stdarg.h>
#include <reg51.h>
extern void putchar(char );

static data long val;
static data volatile char ch;
static data char radix ;
static bit  long_flag = 0;
static bit  string_flag =0;
static bit  short_flag = 0;
static bit sign;
static char * data str ;

static void pvalhex() 
{
	volatile char sp = SP;
	unsigned long lval = val;

	if (!long_flag)
		lval &= 0x0000ffff;

        if (short_flag)
		lval &= 0x000000ff;

	while (lval) {
		ch = "0123456789ABCDEF"[(unsigned short)lval & 0x0f];
		_asm push _ch _endasm;
		lval /= 16;
	}

	while (sp != SP) {
		_asm pop _ch _endasm;
		putchar(ch);
        }
		
}

static void pvaloct() 
{
	char sp ; 
	unsigned long lval;    
	sp = SP;
	if (val < 0) {
		lval = -val;
		sign = 1;
	} else {
		lval = val;
		sign = 0;
	}
		
	if (!long_flag)
		lval &= 0x0000ffff;
        if (short_flag)
		lval &= 0x000000ff;

        while (lval) {
		ch = (lval % 8) + '0';
		_asm push _ch _endasm;	
                lval = lval / 8;
	}

	if (sign) {
		ch = '-';
		_asm push _ch _endasm;
	}
		
	
	while (sp != SP) {
		_asm pop _ch _endasm;
		putchar(ch);
        }
}

static void pvaldec( )  
{
	char sp ; 
	unsigned long lval;    
	sp = SP;
	if (val < 0) {
		lval = -val;
		sign = 1;
	} else {
		lval = val;
		sign = 0;
	}
		
        while (lval) {
		ch = (lval % 10) + '0';
		_asm push _ch _endasm;	
                lval = lval / 10;
	}

	if (sign) {
		ch = '-';
		_asm push _ch _endasm;
	}
		
	
	while (sp != SP) {
		_asm pop _ch _endasm;
		putchar(ch);
        }
}

void printf_small (char * fmt, ... ) reentrant
{
    va_list ap ;
 
    va_start(ap,fmt);
     
    for (; *fmt ; fmt++ ) {
	if (*fmt == '%') {
	    long_flag = string_flag = short_flag = 0;
	    fmt++ ;
	    switch (*fmt) {
	    case 'l':
		long_flag = 1;
		fmt++;
		break;
	    case 'h':
		short_flag = 1;
		fmt++;
	    }
	    
	    switch (*fmt) {
	    case 's':
		string_flag = 1;
		break;
	    case 'd':
		radix = 10;
		break;
	    case 'x':
		radix = 16;
		break;
	    case 'c':
		radix = 0;
		break;
	    case 'o':
		radix = 8;
		break;
	    }

	    if (string_flag) {
		str = va_arg(ap,char _generic *);
		while (*str) putchar(*str++);	       
		continue ;
	    }
	    
	    if (long_flag)
		val = va_arg(ap,long);
	    else
		if (short_flag)
		    val = va_arg(ap,short);
		else
		    val = va_arg(ap,int);
	    
            switch (radix) {
	    case 10:
		pvaldec() ; 
		break;
	    case 16:
		pvalhex (); 
		break;
	    case 0:
		putchar((char)val);
		break;
	    case 8:
		pvaloct() ; 
		break;
	    }
	    
	} else
	    putchar(*fmt);       
    }    
}
