text: #ifndef smprintf
  #define smprintf
  // yeokm1 modified with putDebugChar
  
  /*
      Copyright 2001 Georges Menie
      https://www.menie.org/georges/embedded/small_printf_source_code.html
  
      This program 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 of the License, 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 Lesser General Public License for more details.
  
      You should have received a copy of the GNU Lesser General Public License
      along with this program; if not, write to the Free Software
      Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
  
  /*
  	putchar is the only external dependency for this file,
  	if you have a working putchar, just remove the following
  	define. If the function should be called something else,
  	replace outbyte(c) by your own function call.
  */
  #include "windows.h"
  
  static void putDebugChar(int c){
  
    char str[2] = "\0"; /* gives {\0, \0} */
    str[0] = c;
    OutputDebugString(str);
  }
  
  static void printchar(char **str, int c)
  {
  	//extern int putDebugChar(int c);
  	if (str) {
  		**str = c;
  		++(*str);
  	}
  	else (void)putDebugChar(c);
  }
  
  #define PAD_RIGHT 1
  #define PAD_ZERO 2
  
  static int prints(char **out, const char *string, int width, int pad)
  {
  	register int pc = 0, padchar = ' ';
  
  	if (width > 0) {
  		register int len = 0;
  		register const char *ptr;
  		for (ptr = string; *ptr; ++ptr) ++len;
  		if (len >= width) width = 0;
  		else width -= len;
  		if (pad & PAD_ZERO) padchar = '0';
  	}
  	if (!(pad & PAD_RIGHT)) {
  		for ( ; width > 0; --width) {
  			printchar (out, padchar);
  			++pc;
  		}
  	}
  	for ( ; *string ; ++string) {
  		printchar (out, *string);
  		++pc;
  	}
  	for ( ; width > 0; --width) {
  		printchar (out, padchar);
  		++pc;
  	}
  
  	return pc;
  }
  
  /* the following should be enough for 32 bit int */
  #define PRINT_BUF_LEN 12
  
  static int printi(char **out, int i, int b, int sg, int width, int pad, int letbase)
  {
  	char print_buf[PRINT_BUF_LEN];
  	register char *s;
  	register int t, neg = 0, pc = 0;
  	register unsigned int u = i;
  
  	if (i == 0) {
  		print_buf[0] = '0';
  		print_buf[1] = '\0';
  		return prints (out, print_buf, width, pad);
  	}
  
  	if (sg && b == 10 && i < 0) {
  		neg = 1;
  		u = -i;
  	}
  
  	s = print_buf + PRINT_BUF_LEN-1;
  	*s = '\0';
  
  	while (u) {
  		t = u % b;
  		if( t >= 10 )
  			t += letbase - '0' - 10;
  		*--s = t + '0';
  		u /= b;
  	}
  
  	if (neg) {
  		if( width && (pad & PAD_ZERO) ) {
  			printchar (out, '-');
  			++pc;
  			--width;
  		}
  		else {
  			*--s = '-';
  		}
  	}
  
  	return pc + prints (out, s, width, pad);
  }
  
  static int print(char **out, int *varg)
  {
  	register int width, pad;
  	register int pc = 0;
  	register char *format = (char *)(*varg++);
  	char scr[2];
  
  	for (; *format != 0; ++format) {
  		if (*format == '%') {
  			++format;
  			width = pad = 0;
  			if (*format == '\0') break;
  			if (*format == '%') goto out;
  			if (*format == '-') {
  				++format;
  				pad = PAD_RIGHT;
  			}
  			while (*format == '0') {
  				++format;
  				pad |= PAD_ZERO;
  			}
  			for ( ; *format >= '0' && *format <= '9'; ++format) {
  				width *= 10;
  				width += *format - '0';
  			}
  			if( *format == 's' ) {
  				register char *s = *((char **)varg++);
  				pc += prints (out, s?s:"(null)", width, pad);
  				continue;
  			}
  			if( *format == 'd' ) {
  				pc += printi (out, *varg++, 10, 1, width, pad, 'a');
  				continue;
  			}
  			if( *format == 'x' ) {
  				pc += printi (out, *varg++, 16, 0, width, pad, 'a');
  				continue;
  			}
  			if( *format == 'X' ) {
  				pc += printi (out, *varg++, 16, 0, width, pad, 'A');
  				continue;
  			}
  			if( *format == 'u' ) {
  				pc += printi (out, *varg++, 10, 0, width, pad, 'a');
  				continue;
  			}
  			if( *format == 'c' ) {
  				/* char are converted to int then pushed on the stack */
  				scr[0] = *varg++;
  				scr[1] = '\0';
  				pc += prints (out, scr, width, pad);
  				continue;
  			}
  		}
  		else {
  		out:
  			printchar (out, *format);
  			++pc;
  		}
  	}
  	if (out) **out = '\0';
  	return pc;
  }
  
  /* assuming sizeof(void *) == sizeof(int) */
  
  int printf(const char *format, ...)
  {
  	register int *varg = (int *)(&format);
  	return print(0, varg);
  }
  
  //yeokm1 don't overload system sprintf
  static int sprintf(char *out, const char *format, ...)
  {
  	register int *varg = (int *)(&format);
  	return print(&out, varg);
  }
  
  #ifdef TEST_PRINTF
  int main(void)
  {
  	char *ptr = "Hello world!";
  	char *np = 0;
  	int i = 5;
  	unsigned int bs = sizeof(int)*8;
  	int mi;
  	char buf[80];
  
  	mi = (1 << (bs-1)) + 1;
  	printf("%s\n", ptr);
  	printf("printf test\n");
  	printf("%s is null pointer\n", np);
  	printf("%d = 5\n", i);
  	printf("%d = - max int\n", mi);
  	printf("char %c = 'a'\n", 'a');
  	printf("hex %x = ff\n", 0xff);
  	printf("hex %02x = 00\n", 0);
  	printf("signed %d = unsigned %u = hex %x\n", -3, -3, -3);
  	printf("%d %s(s)%", 0, "message");
  	printf("\n");
  	printf("%d %s(s) with %%\n", 0, "message");
  	sprintf(buf, "justif: \"%-10s\"\n", "left"); printf("%s", buf);
  	sprintf(buf, "justif: \"%10s\"\n", "right"); printf("%s", buf);
  	sprintf(buf, " 3: %04d zero padded\n", 3); printf("%s", buf);
  	sprintf(buf, " 3: %-4d left justif.\n", 3); printf("%s", buf);
  	sprintf(buf, " 3: %4d right justif.\n", 3); printf("%s", buf);
  	sprintf(buf, "-3: %04d zero padded\n", -3); printf("%s", buf);
  	sprintf(buf, "-3: %-4d left justif.\n", -3); printf("%s", buf);
  	sprintf(buf, "-3: %4d right justif.\n", -3); printf("%s", buf);
  
  	return 0;
  }
  
  /*
   * if you compile this file with
   *   gcc -Wall $(YOUR_C_OPTIONS) -DTEST_PRINTF -c printf.c
   * you will get a normal warning:
   *   printf.c:214: warning: spurious trailing `%' in format
   * this line is testing an invalid % at the end of the format string.
   *
   * this should display (on 32bit int machine) :
   *
   * Hello world!
   * printf test
   * (null) is null pointer
   * 5 = 5
   * -2147483647 = - max int
   * char a = 'a'
   * hex ff = ff
   * hex 00 = 00
   * signed -3 = unsigned 4294967293 = hex fffffffd
   * 0 message(s)
   * 0 message(s) with %
   * justif: "left      "
   * justif: "     right"
   *  3: 0003 zero padded
   *  3: 3    left justif.
   *  3:    3 right justif.
   * -3: -003 zero padded
   * -3: -3   left justif.
   * -3:   -3 right justif.
   */
  
  #endif
  
  #endif
  