Convert a very long int value To Hex

[Ahmad Jalil Qarshi]

Hi,

I have an integer value which is very long like 998796744177857 3855.
Now I
want to convert it into equivalent Hex value.

The result must be 8A9C63784361021 F

I have used sprintf(pHex,"% 0X",99879674417 78573855). But it only
returns 8
Hex values.

Kindly note that I am using pure C on Unix.

Thanks in anticipation,

Regards,

Ahmad Jalil Qarshi

[santosh]

Ahmad Jalil Qarshi wrote:

Hi,

I have an integer value which is very long like 998796744177857 3855.
Now I
want to convert it into equivalent Hex value.

The result must be 8A9C63784361021 F

I have used sprintf(pHex,"% 0X",99879674417 78573855). But it only
returns 8
Hex values.

Kindly note that I am using pure C on Unix.

Thanks in anticipation,

Try the "%Lx" or "%llx" format specifier.

[Ahmad Jalil Qarshi]

On Aug 27, 9:05 pm, santosh <santosh....@gm ail.comwrote:

Ahmad Jalil Qarshi wrote:

Hi,

I have an integer value which is very long like 998796744563877 .
Now I
want to convert it into equivalent Hex value.

The result must be 8A9C63784361021 F

I have used sprintf(pHex,"% 0X",99879674456 3877). But it only
returns 8
Hex values.

Kindly note that I am using pure C on Unix.

Thanks in anticipation,

Try the "%Lx" or "%llx" format specifier.

Dear Santosh,

I have used "%Lx" and it returned 7d299ca5
When I used "%llx" it returned 7d299ca50000f0b 2 which is not Hex for
998796744563877 . It must return 38C667D299CA5.

Regards,

Ahmad Jalil Qarshi

[santosh]

Ahmad Jalil Qarshi wrote:

On Aug 27, 9:05 pm, santosh <santosh....@gm ail.comwrote:

>Ahmad Jalil Qarshi wrote:

Hi,

I have an integer value which is very long like 998796744563877 .
Now I
want to convert it into equivalent Hex value.

The result must be 8A9C63784361021 F

I have used sprintf(pHex,"% 0X",99879674456 3877). But it only
returns 8
Hex values.

Kindly note that I am using pure C on Unix.

Thanks in anticipation,

Try the "%Lx" or "%llx" format specifier.

Dear Santosh,

I have used "%Lx" and it returned 7d299ca5
When I used "%llx" it returned 7d299ca50000f0b 2 which is not Hex for
998796744563877 . It must return 38C667D299CA5.

Ensure that you are compiling in C99 conforming mode. The details to do that
will vary according to your compiler. For gcc pass the 'std=c99'
commandline switch.

Ensure that you use an object of type 'long long' or 'unsigned long long' to
store the value.

Ensure that your Standard library has support for C99 and the long long
type. Some broken libraries like Microsoft's default CRT do not have such
support.

The following program works fine on my system and prints the expected
values. Compare it with what you've written.

#include <stdio.h>

int main(void)
{
long long val = 998796744563877 ll;
printf("%lld in hex is: %llx\n", val, val);
return 0;
}

$./t000
998796744563877 in hex is: 38c667d299ca5
$

[Harald van =?UTF-8?B?RMSzaw==?=]

Ahmad Jalil Qarshi wrote:

On Aug 27, 9:05 pm, santosh <santosh....@gm ail.comwrote:

>Ahmad Jalil Qarshi wrote:

Hi,

I have an integer value which is very long like 998796744563877 .
Now I
want to convert it into equivalent Hex value.

The result must be 8A9C63784361021 F

I have used sprintf(pHex,"% 0X",99879674456 3877). But it only
returns 8
Hex values.

Kindly note that I am using pure C on Unix.

Thanks in anticipation,

Try the "%Lx" or "%llx" format specifier.

Dear Santosh,

I have used "%Lx" and it returned 7d299ca5
When I used "%llx" it returned 7d299ca50000f0b 2 which is not Hex for
998796744563877 . It must return 38C667D299CA5.

What santosh posted is correct C99, and while C99 is not widely implemented
in general, it appears from your result that your compiler and library do
support this, but there is a mistake in how you're using it. What exactly
does this program produce?

#include <stdio.h>
int main() {
unsigned long long ull = 998796744563877 ;
printf("%llx\n" , ull);
}

If this doesn't produce 38c667d299ca5, the problem is with your compiler
and/or library. If this does produce 38c667d299ca5, and you cannot figure
out why it does here but not in your program, would you please post a
complete compilable example demonstrating the problem?

[Harald van =?UTF-8?B?RMSzaw==?=]

santosh wrote:

Ahmad Jalil Qarshi wrote:

>On Aug 27, 9:05 pm, santosh <santosh....@gm ail.comwrote:

>>Ahmad Jalil Qarshi wrote:
Hi,

I have an integer value which is very long like 998796744563877 .
Now I
want to convert it into equivalent Hex value.

The result must be 8A9C63784361021 F

I have used sprintf(pHex,"% 0X",99879674456 3877). But it only
returns 8
Hex values.

Kindly note that I am using pure C on Unix.

Thanks in anticipation,

Try the "%Lx" or "%llx" format specifier.

Dear Santosh,

I have used "%Lx" and it returned 7d299ca5
When I used "%llx" it returned 7d299ca50000f0b 2 which is not Hex for
99879674456387 7. It must return 38C667D299CA5.

Ensure that you are compiling in C99 conforming mode. The details to do
that will vary according to your compiler. For gcc pass the 'std=c99'
commandline switch.

Ensure that you use an object of type 'long long' or 'unsigned long long'
to store the value.

Ensure that your Standard library has support for C99 and the long long
type. Some broken libraries like Microsoft's default CRT do not have such
support.

The following program works fine on my system and prints the expected
values. Compare it with what you've written.

#include <stdio.h>

int main(void)
{
long long val = 998796744563877 ll;
printf("%lld in hex is: %llx\n", val, val);
return 0;
}

$./t000
998796744563877 in hex is: 38c667d299ca5
$

%lld prints signed long long values, %llx prints unsigned long long values.
Using %llx for signed values is not likely to cause errors, but strictly
speaking, it's not valid, and it can be trivially avoided here:

unsigned long long val = 998796744563877 ll;
printf("%llu in hex is: %llx\n", val, val);

[Walter Roberson]

In article <11************ *********@q4g20 00prc.googlegro ups.com>,
Ahmad Jalil Qarshi <Ah************ ****@gmail.comw rote:

>I have an integer value which is very long like 998796744177857 3855.
Now I
want to convert it into equivalent Hex value.

>The result must be 8A9C63784361021 F

>I have used sprintf(pHex,"% 0X",99879674417 78573855). But it only
returns 8
Hex values.

When you have a literal constant that long, it is usually
not a good idea to count on the default integral promotions
to get the type right for you. On most systems,
0x8A9C637843610 21F is too long to fit into an int, unsigned
int, long, or unsigned long.

If you are using C89, the list would stop there, and
0x8A9C637843610 21F would undergo the standard unsigned long
reductions until the result fit into an unsigned long, commonly
(but not universally) resulting in 0x4361021F . But then you have
the problem that %0X is the format for an unsigned int, and would
need %0lX for unsigned long. And if you had a system with
an unusually large range for long, the value could end up as
of type long (signed) rather than unsigned long, in which case
it would have to be type cast to unsigned long before you could
use the %0lX format.

If you are using C99, the list would continue on to
long long and unsigned long long; 0x8A9C637843610 21F would be
too big for long long on most (but not all) systems, but
would fit in unsigned long long on all systems that support
long long. But again it might happen to fit within signed long long
so it should be cast to unsigned long long before using a
%0llX format.

But the type you end up with becomes dependant upon the exact
ranges supported by the machine when you give such a large
constant without specifying a type modifier. It is better to be
certain, by coding something such as 998796744177857 3855ULL
and then you *know* the type and no that it won't undergo any
unexpected value conversions (if it compiles at all.)
--
I was very young in those days, but I was also rather dim.
-- Christopher Priest

[santosh]

Harald van D?k wrote:

santosh wrote:

>Ahmad Jalil Qarshi wrote:

>>santosh wrote:
Ahmad Jalil Qarshi wrote:
Hi,

I have an integer value which is very long like 998796744563877 .
Now I want to convert it into equivalent Hex value.

<snip>

>The following program works fine on my system and prints the expected
values. Compare it with what you've written.

#include <stdio.h>

int main(void)
{
long long val = 998796744563877 ll;
printf("%lld in hex is: %llx\n", val, val);
return 0;
}

$./t000
99879674456387 7 in hex is: 38c667d299ca5
$

%lld prints signed long long values, %llx prints unsigned long long
values. Using %llx for signed values is not likely to cause errors, but
strictly speaking, it's not valid, and it can be trivially avoided here:

unsigned long long val = 998796744563877 ll;
printf("%llu in hex is: %llx\n", val, val);

Thanks. I should have known that. Also, I think, a cast of val to unsigned
long long would suffice, would it not?

[Harald van =?UTF-8?B?RMSzaw==?=]

santosh wrote:

Harald van D?k wrote:

>santosh wrote:

>>The following program works fine on my system and prints the expected
values. Compare it with what you've written.

#include <stdio.h>

int main(void)
{
long long val = 998796744563877 ll;
printf("%lld in hex is: %llx\n", val, val);
return 0;
}

$./t000
9987967445638 77 in hex is: 38c667d299ca5
$

%lld prints signed long long values, %llx prints unsigned long long
values. Using %llx for signed values is not likely to cause errors, but
strictly speaking, it's not valid, and it can be trivially avoided here:

unsigned long long val = 998796744563877 ll;
printf("%llu in hex is: %llx\n", val, val);

Thanks. I should have known that. Also, I think, a cast of val to unsigned
long long would suffice, would it not?

Indeed, that would work just as well here.

[cr88192]

"Ahmad Jalil Qarshi" <Ah************ ****@gmail.comw rote in message
news:11******** *************@q 4g2000prc.googl egroups.com...

Hi,

I have an integer value which is very long like 998796744177857 3855.
Now I
want to convert it into equivalent Hex value.

The result must be 8A9C63784361021 F

I have used sprintf(pHex,"% 0X",99879674417 78573855). But it only
returns 8
Hex values.

Kindly note that I am using pure C on Unix.

minor comments:
a number this size should really have 'LL' or 'ULL'.
998796744177857 3855ULL (value too large for normal LL).

next up, as others have noted:
you need something like: '%llx'.

however, annoyingly, certain C libraries are broken (and do not support
'll').
in this particular case, you may be better off converting the value to a
string manually.

an example:
static char *hexchars="0123 456789ABCDEF";

li=998796744177 8573855ULL;
for(i=0; i<16; i++)pHex[i]=hexchars[(li>>((15-i)*4))&0xF];
pHex[16]=0;
or, in a slightly more traditional style:
li=998796744177 8573855ULL; i=16; t=pHex;
while(i--)*t++=hexchars[(li>>(i<<2))&0x F];
*t++=0;

(will state up front, ones' conventions are a matter of personal taste...).

or such...

Thanks in anticipation,

Regards,

Ahmad Jalil Qarshi