Printing long long int values

use sprintf to format it with leading zeros.

long long license = 12345678987654321L;
printf("%020lld", license)

Mr. Simmons is on the right track and k5054 also. I use a variant of that to do it :

sprintf( outputBuffer, "%020I64d", sixtyfourbitvalue );

That will be twenty digits with leading zeros.

Incidentally, in stdint.h it has this definition :

#define INT64_MAX        9223372036854775807i64

so you might want to try a similar format. That is, if you are using visual studio. Those are not standard formats for 64-bit values.

For a fun exercise, try writing a function to accept a 64-bit integer and load a text buffer with a comma-separated string. For example: 1,234,456,890. Depending on your location, you might use dots for separating the thousands so for bonus credit use the locale to select the appropriate separation character.

You need to specify the minimum number of digits to print in your format, so use the following:

printf("%.20lld\n", license);

That will correctly print all values, e.g.:

00123456789876543219

00000000000123456789

However, unless you are using this value in calculations you could just input it as a string and then prepend the requisite number of zeroes.

unsigned long long int i=0;
printf("\nenter num\n");
scanf("%llu",&i);
printf("%.20llu\n",cp);