I have this string.
char * data = "A1B2C3D4E5F6A7B8";
Here each A1 B2 C3 D4 E5 F6 A7 B8 will be bytes for unsigned char* buffer.
My concern is how to convert the data into unsigned char* buffer.
unsigned char* buffer;
buffer = (unsigned char*)data;
I will use the buffer for a parameter of a function like this to write the data into memory.
int abc(uint64_t address, buffer, uint32_t lenght);
Can anyone please give me a correct way?
Here it is a demo about the char* buffer, unsigned char* and string.
// test.cpp
#include<iostream>
using namespace std;
void fun(unsigned char* pt) {
cout<<*pt<<*(pt+1)<<endl; // print first and second element
}
int main(){
char Data[] = "abcde"; // a string with 6 elements stored in char array.
char* data = Data; // char pointer point to the char array
unsigned char* buffer; // declare an unsigned char
buffer = (unsigned char*) data; // buffer points to the same address data pointed.
fun(buffer); // function requires an unsigned char pointer
return 0;
}
The output
ab
To compile and run
g++ -Wall test.cpp;
./a.out
P.S.
char * data = "A1B2C3D4E5F6A7B8";
The above line would cause a warning when compiling because the string is immutable. Better changes it to char const * data = "A1B2C3D4E5F6A7B8";
char * data = "A1B2C3D4E5F6A7B8";is not allowed.datamust beconst char*. What does buffer mean here? Do you allocate memory for it somewhere?buffernow doesn't point to any allocated memory, it points to the string literal, after your edit of the question.