printing format for hexadecimal signed number

Shell Programming and Scripting
1

Hello Experts,,

   I m facing a problem as follows..  need help..

When I am giving the below command it gives me three digit hexadecimal number , for ex :-

printf("%0.3x", 10);
Output: 00a

But I want the same for signed number also.

Now when I am specifiying the same format for singed number like

printf("%0.3x", -1 );

It gives me the output ffffffff

But I want only last 3 bytes ,ie fff

Thanks in Advance .......
Prady..

2

Your conversion modifier is the problem. The 'x' conversion modifier takes an integer argument and converts it to unsigned lowercase hexadecimal notation.

3

Thank's for your kind reply ..

But I think its converting to a signed Hexadecimal number not to "unsigned lowercase hexadecimal " my friend..

as -1 in singed hexadecimal number is equal to ffffffff
and like wise if I will give printf("%x", -10);
which will give me a output fffffff6 . As -10 in signed hexadecimal number is equal to fffffff6 .

I think its depend on machine whether it is a 32 bit or 64 bit machine ,
But my problem is I want to take only the last 3 digits of the hexadecimal number ..
Ex: printf("%x", -10); sholud give me output ff6 not fffffff6 .

I am curious to know is there any format specifier in nawk or gawk in which I can get only the last three digits.

4

There is no format in awk that permits to get only the last three last digit.
But you can write your own function, for example :

function toHexa(number, len      ,str) {
   if (len == 0) len = 2;
   str = sprintf("%0" len "." len "x", number);
   return substr(str, length(str)-len+1) "";
}
{
   print $1, "=>", toHexa($1,3);
}

Input:

0
1
27
3210
-1
-30

Output:

0 => 000
1 => 001
27 => 01b
3210 => c8a
-1 => fff
-30 => fe2

Jean-Pierre.

5

Thanks Genious Jean .. Where do you get these ideas..

6

May I know the reason why did you use the below line
str = sprintf("%0" len "." len "x", number);
instead of just str = sprint("%x", number )

Thanks in Advance..

7

Or directly:

x=sprintf("%x",-10);print substr(x,length(x)-2)
8

For positive numbers lower than 256, the result is not 3 digits.

Jean-Pierre.

9

So what?
You'll get <3 chars output.

10

That was the initial requirement.

Jean-Pierre.

11

OK.

x=sprintf("%.3x",1);print substr(x,length(x)-2)