how to print a double in hex using a single printf in GCC ?

[vinodstanur]

how to print a double in hex using a single printf in GCC ?

 

[papunblg]

#include <stdio.h>
#include <stdlib.h>
#include <float.h>

int main (void)
{
double d;

d = 2;
printf("Ex 1: 2 in hex: %a\n\n",d);

d = 256;
printf("Ex 2: 2^8 in hex: %a\n\n",d);

d = 0.015625; //= 2^-6
printf("Ex 3: 2^-6 in hex: %a\n\n",d);

d = 0.857421875;
printf("Ex 4: 0.857421875 in hex: %a\n\n",d);

d = DBL_MAX;
printf("Ex 5: DBL_MAX in hex: %a\n\n",d);

d = DBL_MIN; //Smallest double (normalized)
printf("Ex 6: DBL_MIN in hex: %a\n\n",d);

d = 0x1p-1074; //Smallest double (unnormalized)
printf("Ex 7: 0x1p-1074 in hex: %a\n\n",d);

d = 3.1415926;
printf("Ex 8: 3.1415926 in upper case hex: %A\n\n",d);

d = 0.1;
printf("Ex 9: 0.1 in hex: %a\n\n",d);

d = 0x3.3333333333334p-5;
printf("Ex 10: 0x3.3333333333334p-5 in hex: %a\n\n",d);

d = 0xcc.ccccccccccdp-11;
printf("Ex 11: 0xcc.ccccccccccdp-11 in hex: %a\n\n",d);

d = strtod("0x1.999999999999ap-4",NULL);
printf("Ex 12: strtod 0x1.999999999999ap-4 in decimal: %0.1f\n",d);
}

//////////////////////////////////////////////output below
Ex 1: 2 in hex: 0x1p+1

Ex 2: 2^8 in hex: 0x1p+8

Ex 3: 2^-6 in hex: 0x1p-6

Ex 4: 0.857421875 in hex: 0x1.b7p-1

Ex 5: DBL_MAX in hex: 0x1.fffffffffffffp+1023

Ex 6: DBL_MIN in hex: 0x1p-1022

Ex 7: 0x1p-1074 in hex: 0x0.0000000000001p-1022

Ex 8: 3.1415926 in upper case hex: 0X1.921FB4D12D84AP+1

Ex 9: 0.1 in hex: 0x1.999999999999ap-4

Ex 10: 0x3.3333333333334p-5 in hex: 0x1.999999999999ap-4

Ex 11: 0xcc.ccccccccccdp-11 in hex: 0x1.999999999999ap-4

Ex 12: strtod 0x1.999999999999ap-4 in decimal: 0.1


please see Hexadecimal Floating-Point Constants - Exploring Binary for details