Question

I have a text file with hexadecimal values, after I fscanf a value I need to know how I can convert it from hexadecimal string to an int. And then convert it back to hexadecimal string for a later print. Anyone knows an algorithm for this? thank you.

Answer 1

You should use the %x format specifier instead of %s to read your values. This will read the data as hexadecimal integers.

For example, if your file looks like this:

ff3c 5a cb2d

Then you can read those 3 values like this:

int a, b, c;
fscanf(fp, "%x %x %x", &a, &b, &c); // a = 0xff3c, b = 0x5a, c = 0xcb2d