Re: printk and long long

["Richard B. Johnson" <root@chaos.analogic.com>]

On Wed, 11 Feb 2004 wdebruij@dds.nl wrote:

> how about simply using a shift to output two regular longs, i.e.
>
> printk("%ld%ld",loff_t >> (sizeof(long) * 8), loff_t << sizeof(long) * 8 >>
> sizeof(long) * 8);
>
> perhaps you could even place this ghastly code in a macro if you have to access
> it often (so that you don't have to look at it :)?
>
> I know it's not pretty, but at least the %ld is considered standard printf
> functionality. I don't think %lld (even if it is implemented in some printf
> derivates) can be considered portable.
>
> Willem
> Citeren sting sting <zstingx@hotmail.com>:
>
> > Hello,
> > I am trying to perfrom printk with a variable of type long long.
> > (loff_t is that type and it is long long , as can be seen in
> > posix+types.h).
> > what is the format string for such a type ?
> > I had tried %lld" but it gace wrpng results.
> > regards,
> > sting

This is probably portable. I could do it much simpler in
assembly but it wouldn't be portable.

Printing both unsigned long long and signed long long.




#include <stdio.h>

unsigned long long tester0 = 12345678901234567890ULL;
unsigned long long tester1 = 0xffffffffffffffff;


char *ulltoa(char *buf, unsigned long long val)
{
    char tmp[0x20];
    char *cp = tmp;
    char *rp = buf;
    do {
            *cp++ = (char) (val%10ULL) + '0';
            val /= 10ULL;
       } while (val);
    do {
           *buf++ = *(--cp);
       } while (cp != tmp);
    *buf = 0x00;
    return rp;
}

char *lltoa(char *buf, long long val)
{
   char *cp = buf;
   if(val < 0) {
        *cp++ = (char) '-';
        val = ~val + 1LL;
   }
   (void) ulltoa(cp, (unsigned long)val);
   return buf;
}

int main()
{
    char buf[0x100];

    printf("%llu\n", 0ULL);
    printf("%llu\n", tester0);
    printf("%llu\n", tester1);
    printf("%s\n", ulltoa(buf, 0ULL));
    printf("%s\n", ulltoa(buf, tester0));
    printf("%s\n", ulltoa(buf, tester1));
    printf("%s\n", lltoa(buf, tester1));

    return 0;
}



Cheers,
Dick Johnson
Penguin : Linux version 2.4.24 on an i686 machine (797.90 BogoMips).
            Note 96.31% of all statistics are fiction.