Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!uunet!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!brutus.cs.uiuc.edu!ux1.cso.uiuc.edu!ux1.cso.uiuc.edu!m.cs.uiuc.edu!carroll
From: carroll@m.cs.uiuc.edu
Newsgroups: comp.lang.c
Subject: Re: integer to string function (itoa())
Message-ID: <4700055@m.cs.uiuc.edu>
Date: 30 Jun 90 17:24:00 GMT
References: <22888@boulder.Colorado.EDU>
Lines: 50
Nf-ID: #R:boulder.Colorado.EDU:22888:m.cs.uiuc.edu:4700055:000:1435
Nf-From: m.cs.uiuc.edu!carroll    Jun 30 12:24:00 1990


I got a number of requests for this, so here it is:
(This code is taken out of Epoch, where it works just fine).
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
char *
UnsignedLongToString(n,base)
     unsigned long n;
     unsigned int base;
{
  char *digit = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
  static char LongToStringBuffer[34];	/* 32+nul+negative sign */
  char *s = LongToStringBuffer + 33; /* at most 33 characters in binary */

  *s = 0;			/* terminate */
  while (n)			/* something there */
    {
    *--s = digit[n % base];		/* store bottom digit */
    n /= base;			/* shift right */
    }
  if (*s == 0) *--s = '0';		/* in case nothing was put in string */
  return s;
}

char *
LongToString(n,base)
     long n;
     int base;
{
  char *s;

  if (n < 0)
    {
      s = UnsignedLongToString((unsigned long) -n, base);
      *--s = '-';
    }
  else s = UnsignedLongToString((unsigned long) n, base);
  return s;
}
/* ------------------------------------------------------------------------ */
main()
{
  printf("%s\n",LongToString(-1234567,10));
  printf("%s\n",UnsignedLongToString(7654321,10));
  printf("%s\n",LongToString(0x12345,16));
}

Alan M. Carroll                Barbara/Marilyn in '92 :
carroll@cs.uiuc.edu            + This time, why not choose the better halves?
Epoch Development Team         
CS Grad / U of Ill @ Urbana    ...{ucbvax,pur-ee,convex}!cs.uiuc.edu!carroll