Keep Leading zeros C

Question

I am trying to read the memory addresses from /proc//maps and I use the following code

for (ptr = NULL; getline(&ptr, &n, file) > 0;)     {
   if (ptr         


        

Answer 1

You're reading these values into integers; integers don't have leading zeros.

If you know how many digits you want to pad out the length to, you can specify that in your format string:

printf("r0: %08lx, r1: %08lx\n", r0, r1);

There's no way to store and recall the exact number of leading zeroes without storing the value in a different format (e.g, a string), though.

Answer 2

Use the 0 flag (which specifies leading zeros), followed by the padded length.

printf("r0: %08lx, r1: %08lx\n", r0, r1);
             ^^         ^^

This link is a good reference to look at.