Question

I am trying to copy the memory value of int into the char buffer. The code looks like below,

#define CPYINT(a, b) memcpy(a, &b, 4)
............

char str1[4];
int i = 1;
CPYINT(str1, i);
printf("%s",s);

...........

When I print str1 it’s blank. Please clarify.

Answer 1

You are copying the byte representation of an integer into a char array. You then ask printf to interpret this array as a null terminating string : str1[0] being zero, you are essentially printing an empty string (I’m skipping the endianness talk here).

What did you expect ? Obviously, if you wanted to print a textual representation of the integer i, you should use printf("%d", i).