I have a string like
string test = "48656c6c6f20576f726c64";
and I would like to convert it to
unsigned char state[] = {0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77,
0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff};
unsigned char bytearray[60];
int w;
for (w=0;w<str.length();w+2) {
bytearray[w] = "0x" + str2[w];
}
It doesn't seem to work. Any help would be appreciated
Try something more like this instead:
#include <vector>
#include <string>
std::string test = "48656c6c6f20576f726c64";
size_t numbytes = test.size() / 2;
std::vector<unsigned char> bytearray;
bytearray.reserve(numbytes);
for (size_t w = 0, x = 0; w < numbytes; ++w, x += 2) {
unsigned char b;
char c = test[x];
if ((c >= '0') && (c <= '9'))
b = (c - '0');
else if ((c >= 'A') && (c <= 'F'))
b = 10 + (c - 'A');
else if ((c >= 'a') && (c <= 'f'))
b = 10 + (c - 'a');
else {
// error!
break;
}
b <<= 4;
c = test[x+1];
if ((c >= '0') && (c <= '9'))
b |= (c - '0');
else if ((c >= 'A') && (c <= 'F'))
b |= 10 + (c - 'A');
else if ((c >= 'a') && (c <= 'f'))
b |= 10 + (c - 'a');
else {
// error!
break;
}
bytearray.push_back(b);
}
// use bytearray as needed...
Alternatively:
#include <vector>
#include <string>
#include <iomanip>
std::string test = "48656c6c6f20576f726c64";
size_t numbytes = test.size() / 2;
std::vector<unsigned char> bytearray;
bytearray.reserve(numbytes);
for(size_t w = 0, x = 0; w < numbytes; ++w, x += 2)
{
std::istringstream iss(test.substr(x, 2));
unsigned short b;
if (!(iss >> std::hex >> b)) {
// error!
break;
}
bytearray.push_back(static_cast<unsigned char>(b));
}
// use bytearray as needed...
explained here C++ convert hex string to signed integer
so do something like this:
unsigned int x;
std::string substring; // you will need to figure out how to get this
std::stringstream ss;
ss << std::hex << substring;
ss >> x;
x is what you would need to store an your array. "48" would actually be a parsed part of your string. Look here So you might need to change the type. Play around with it. Also i think you were parsing your string incorrectly. check this out Split string using loop to specific length sub-units
std::hex` iostream manipulator, and astd::ostringstream.or astd::istringstreambytearray[w]. I recommend reviewing the sections about data types in your favorite C++ reference. A single element in a character array can only contain a single character, not multiple characters.