printf.c

Tiny printf function for embedded programming

/*
File: printf.c

Copyright (C) 2004  Kustaa Nyholm

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.

This library 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
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

*/

#include "printf.h"

typedef void (*putcf) (void*,char);
static putcf stdout_putf;
static void* stdout_putp;


#ifdef PRINTF_LONG_SUPPORT

static void uli2a(unsigned long int num, unsigned int base, int uc,char * bf)
	{
	int n=0;
	unsigned int d=1;
	while (num/d >= base)
		d*=base;		 
	while (d!=0) {
		int dgt = num / d;
		num%=d;
		d/=base;
		if (n || dgt>0|| d==0) {
			*bf++ = dgt+(dgt<10 ? '0' : (uc ? 'A' : 'a')-10);
			++n;
			}
		}
	*bf=0;
	}

static void li2a (long num, char * bf)
	{
	if (num<0) {
		num=-num;
		*bf++ = '-';
		}
	uli2a(num,10,0,bf);
	}

#endif

static void ui2a(unsigned int num, unsigned int base, int uc,char * bf)
	{
	int n=0;
	unsigned int d=1;
	while (num/d >= base)
		d*=base;		
	while (d!=0) {
		int dgt = num / d;
		num%= d;
		d/=base;
		if (n || dgt>0 || d==0) {
			*bf++ = dgt+(dgt<10 ? '0' : (uc ? 'A' : 'a')-10);
			++n;
			}
		}
	*bf=0;
	}

static void i2a (int num, char * bf)
	{
	if (num<0) {
		num=-num;
		*bf++ = '-';
		}
	ui2a(num,10,0,bf);
	}

static int a2d(char ch)
	{
	if (ch>='0' && ch<='9') 
		return ch-'0';
	else if (ch>='a' && ch<='f')
		return ch-'a'+10;
	else if (ch>='A' && ch<='F')
		return ch-'A'+10;
	else return -1;
	}

static char a2i(char ch, char** src,int base,int* nump)
	{
	char* p= *src;
	int num=0;
	int digit;
	while ((digit=a2d(ch))>=0) {
		if (digit>base) break;
		num=num*base+digit;
		ch=*p++;
		}
	*src=p;
	*nump=num;
	return ch;
	}

static void putchw(void* putp,putcf putf,int n, char z, char* bf)
	{
	char fc=z? '0' : ' ';
	char ch;
	char* p=bf;
	while (*p++ && n > 0)
		n--;
	while (n-- > 0) 
		putf(putp,fc);
	while ((ch= *bf++))
		putf(putp,ch);
	}

void tfp_format(void* putp,putcf putf,char *fmt, va_list va)
	{
	char bf[12];
    
	char ch;


	while ((ch=*(fmt++))) {
		if (ch!='%') 
			putf(putp,ch);
		else {
			char lz=0;
#ifdef 	PRINTF_LONG_SUPPORT
			char lng=0;
#endif
			int w=0;
			ch=*(fmt++);
			if (ch=='0') {
				ch=*(fmt++);
				lz=1;
				}
			if (ch>='0' && ch<='9') {
				ch=a2i(ch,&fmt,10,&w);
				}
#ifdef 	PRINTF_LONG_SUPPORT
			if (ch=='l') {
				ch=*(fmt++);
				lng=1;
			}
#endif
			switch (ch) {
				case 0: 
					goto abort;
				case 'u' : {
#ifdef 	PRINTF_LONG_SUPPORT
					if (lng)
						uli2a(va_arg(va, unsigned long int),10,0,bf);
					else
#endif
					ui2a(va_arg(va, unsigned int),10,0,bf);
					putchw(putp,putf,w,lz,bf);
					break;
					}
				case 'd' :  {
#ifdef 	PRINTF_LONG_SUPPORT
					if (lng)
						li2a(va_arg(va, unsigned long int),bf);
					else
#endif
					i2a(va_arg(va, int),bf);
					putchw(putp,putf,w,lz,bf);
					break;
					}
				case 'x': case 'X' : 
#ifdef 	PRINTF_LONG_SUPPORT
					if (lng)
						uli2a(va_arg(va, unsigned long int),16,(ch=='X'),bf);
					else
#endif
					ui2a(va_arg(va, unsigned int),16,(ch=='X'),bf);
					putchw(putp,putf,w,lz,bf);
					break;
				case 'c' : 
					putf(putp,(char)(va_arg(va, int)));
					break;
				case 's' : 
					putchw(putp,putf,w,0,va_arg(va, char*));
					break;
				case '%' :
					putf(putp,ch);
				default:
					break;
				}
			}
		}
	abort:;
	}


void init_printf(void* putp,void (*putf) (void*,char))
	{
	stdout_putf=putf;
	stdout_putp=putp;
	}

void tfp_printf(char *fmt, ...)
	{
	va_list va;
	va_start(va,fmt);
	tfp_format(stdout_putp,stdout_putf,fmt,va);
	va_end(va);
	}

static void putcp(void* p,char c)
	{
	*(*((char**)p))++ = c;
	}



void tfp_sprintf(char* s,char *fmt, ...)
	{
	va_list va;
	va_start(va,fmt);
	tfp_format(&s,putcp,fmt,va);
	putcp(&s,0);
	va_end(va);
	}