On Tue, 16 May 2000, Fong Siu Lung Gordon wrote:
> Yes, 14-character. My method is to individually cut the 14-character into
> 14 tokens and calculate the check digit from these tokens.  It works.  The
> problem is I have to calculate the check digit for a series of borrow card
> not just one and I don't to type it again and again.  The method I though
> of is to make a copy the start borrow card and increment by 1 each time.
> Then re-calculate the check digit and the new borrow card number.  The
> probelm is max int of my system (i386) is largest enough to hold the
> 14-charater digit.  That is the point.

If you're willing to do this in C++, you have a few options:
 1. Use the BigInt class, it lets you work with huge numbers.
 2. Use code in AddToBarCode() below

Alternately this code could probably be converted to C quite easily. Hope
this helps.

Jared

--

#include <iostream>
#include <string>
#include <cstdlib>

string AddToBarCode(string);

int
main()
{
	string BarCode = "12345678901239";

	cout << AddToBarCode(BarCode) << endl;

	return(0);
}

string AddToBarCode(string BarCode)
// Variables:	BarCode		Initial barcode value
// Returns:	New bar code as type string
{
	int StringLen = 0;
	int Flag = 0;
	char WorkingChar;
	string TempString = BarCode;
	string TempChar;

	StringLen = TempString.length();
	WorkingChar = StringLen - 1;

	while (!Flag)
	{
		TempChar = "";
		TempChar += TempString[WorkingChar];

		if (atoi(TempChar.c_str()) + 1 < 10)
		{
			TempString[WorkingChar] += 1;
			Flag = 1;
		} else {
			TempString[WorkingChar] = '0';
			WorkingChar--;
		}
		if (WorkingChar < 0)
		{
			TempString = "1" + TempString;
			Flag = 1;
		}
	}
	return(TempString);
}