Converting a hex string to a byte array

Question

What is the best way to convert a variable length hex string e.g. \"01A1\" to a byte array containing that data.

i.e converting this:

st         


        

Answer 1

You said "variable length." Just how variable do you mean?

For hex strings that fit into an unsigned long I have always liked the C function strtoul. To make it convert hex pass 16 as the radix value.

Code might look like:

#include 
std::string str = "01a1";
unsigned long val = strtoul(str.c_str(), 0, 16);