/*
**  COMMAFMT.C
**
**  Public domain by Bob Stout
**
**  Notes:  1. Use static buffer to eliminate error checks on buffer overflow
**             and reduce code size.
**          2. By making the numeric argument a long and prototyping it before
**             use, passed numeric arguments will be implicitly cast to longs
**             thereby avoiding int overflow.
**          3. Use the thousands grouping and thousands separator from the
**             ANSI locale to make this more robust.
*/

#pragma alloc_text(MISC8,commafmt,hundfmt)

#include <stdlib.h>
#include <stdio.h>
#include <string.h>

size_t commafmt(char   *buf,            /* Buffer for formatted string  */
                int     bufsize,        /* Size of buffer               */
                long    N)              /* Number to convert            */
{
        int len = 1, posn = 1, sign = 1;
        char *ptr = buf + bufsize - 1;

        if (2 > bufsize)
        {
ABORT:          *buf = 0;
                return 0;
        }

        *ptr-- = 0;
        --bufsize;
        if (0L > N)
        {
                sign = -1;
                N = -N;
        }

        for ( ; len <= bufsize; ++len, ++posn)
        {
                *ptr-- = (char)((N % 10L) + '0');
                if (0L == (N /= 10L))
                        break;
                if (0 == (posn % 3))
                {
                        *ptr-- = ',';
                        ++len;
                }
                if (len >= bufsize)
                        goto ABORT;
        }

        if (0 > sign)
        {
                if (0 == bufsize)
                        goto ABORT;
                *ptr-- = '-';
                ++len;
        }

        strcpy(buf, ++ptr);
        return (size_t)len;
}


size_t hundfmt (char *buf,int bufsize,unsigned long N) {

  char           tbuf[34];
  register char *pt,*p;
  register int   len;

  sprintf(tbuf,"%02lu",N);
  len = strlen(tbuf);
  pt = tbuf;
  p = buf;
  bufsize--;
  while(*pt && (p - buf) < bufsize) {
    if(len == 2) {
      *p = '.';
      p++;
    }
    *p = *pt;
    p++;
    pt++;
    len--;
  }
  *p = 0;
  return p - buf;
}