Thread: Custom format specifiers ???

Is it possible to make our own format specifiers ??

data type can be redefined either using typedef or #define

Code:

#define LL long long
typedef long long LL ;

but what about this :

Code:

printf("%llu",var);

is it possible to change %llu into something more general at the beginning itself ?

Thank you

If you want to add code to printf()'s header file (stdio.h), then sure. The source is right there.

If your compiler supports a type long long integer, then your printf() should also support printing long long int's.

The down and dirty method would be to just write a function to take your long long into a char array, and make the format changes you want to make, within that array, right inside your own function. Then you can print it just as you wanted it, as a string.

Another way you can do work with very large int's is to have unsigned long's count up to the first million. That triggers the millions counter variable to increment by one, and resets the one's variable.

You can repeat this for billions, trillions, and quadrillions, and go on as high as you need to. This is what I'm doing in a current search project for certain Sudoku grids. Every day the searcher finds, tests, and counts, about 20 billion puzzle grids. << cool! >>