uint64_t nach char[]

#include <stdlib.h>

#include <stddef.h>

#include <stdio.h>

#include <string.h>

#include <stdint.h>

char *uint64toa( uint64_t value, char *puffer, int base )

{

    static const char digits[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";

    char *puffer_end = puffer;

    char *puffer_anf = puffer;

    // generate string in reverse order:

    do

    {

        *puffer_end++ = digits[value%base];

        value /= base;

    }

    while( value );

    *puffer_end-- = '\0'; // terminate

    // reverse to correct order:

    while( puffer_anf<puffer_end )

    {

        char  tmp = *puffer_anf;

        *puffer_anf++ = *puffer_end;

        *puffer_end-- = tmp;

    }

    return puffer;

}

int main( int nargs, char **args )

{

    uint64_t  testwert = 123456;

    char      puffer[20];

    uint64toa( testwert, puffer, 16 );

    printf( "<%llx> <%s>\n", testwert, puffer );

    return 0;

}