File content as of revision 2:81364824d56a:

/*
  Copyright (c) 2011 Arduino.  All right reserved.

  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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
*/

#include "itoa.h"
#include <string.h>

#ifdef __cplusplus
extern "C" {
#endif // __cplusplus

#if 0
/* reverse:  reverse string s in place */
static void reverse(char s[])
{
  int i, j ;
  char c ;

  for (i = 0, j = strlen(s) - 1 ; i < j ; i++, j--) {
    c = s[i] ;
    s[i] = s[j] ;
    s[j] = c ;
  }
}

/* itoa:  convert n to characters in s */
extern void itoa(int n, char s[])
{
  int i, sign ;

  if ((sign = n) < 0) {  /* record sign */
    n = -n;          /* make n positive */
  }

  i = 0;
  do {
    /* generate digits in reverse order */
    s[i++] = n % 10 + '0';   /* get next digit */
  } while ((n /= 10) > 0) ;     /* delete it */

  if (sign < 0) {
    s[i++] = '-';
  }

  s[i] = '\0';

  reverse(s) ;
}

#else

extern char *itoa(int value, char *string, int radix)
{
  return ltoa(value, string, radix) ;
}

extern char *ltoa(long value, char *string, int radix)
{
  char tmp[33];
  char *tp = tmp;
  long i;
  unsigned long v;
  int sign;
  char *sp;

  if (string == NULL) {
    return 0 ;
  }

  if (radix > 36 || radix <= 1) {
    return 0 ;
  }

  sign = (radix == 10 && value < 0);
  if (sign) {
    v = -value;
  } else {
    v = (unsigned long)value;
  }

  while (v || tp == tmp) {
    i = v % radix;
    v = v / radix;
    if (i < 10) {
      *tp++ = i + '0';
    } else {
      *tp++ = i + 'a' - 10;
    }
  }

  sp = string;

  if (sign) {
    *sp++ = '-';
  }
  while (tp > tmp) {
    *sp++ = *--tp;
  }
  *sp = 0;

  return string;
}
#if __GNUC__ > 4 || (__GNUC__ == 4 && (__GNUC_MINOR__ > 9 || \
   (__GNUC_MINOR__ == 9 && __GNUC_PATCHLEVEL__ > 2)))
extern char *utoa(unsigned value, char *string, int radix)
#else
extern char *utoa(unsigned long value, char *string, int radix)
#endif
{
  return ultoa(value, string, radix) ;
}

extern char *ultoa(unsigned long value, char *string, int radix)
{
  char tmp[33];
  char *tp = tmp;
  long i;
  unsigned long v = value;
  char *sp;

  if (string == NULL) {
    return 0;
  }

  if (radix > 36 || radix <= 1) {
    return 0;
  }

  while (v || tp == tmp) {
    i = v % radix;
    v = v / radix;
    if (i < 10) {
      *tp++ = i + '0';
    } else {
      *tp++ = i + 'a' - 10;
    }
  }

  sp = string;


  while (tp > tmp) {
    *sp++ = *--tp;
  }
  *sp = 0;

  return string;
}
#endif /* 0 */

#ifdef __cplusplus
} // extern "C"
#endif // __cplusplus