reading data in C++ - c++

Question

I am having the matlab code to read binary data:
**nfft = 256;
navg = 1024;
nsamps = navg * nfft;
f_s = 8e6;
nblocks = floor(10 / (nsamps / f_s));
for i = 1:nblocks
nstart = 1 + (i - 1) * nsamps;
fid = fopen('data.dat'); % binary data and 320 MB
fseek(fid,4 * nstart,'bof');
y = fread(fid,[2,nsamps],'short');
x = complex(y(1,:),y(2,:));
end**
it will give me complex data with the length up to 8e6.
I am trying to write C++ to do the same function what matab does, but I could not get all the data or they are not the same original.
Can anyone help for ideals?
Here is my C++ code which I am working on.
Thank you so much.
#include <cstdio>
#include <cstring>
#include <iostream>
#include <complex>
#include <vector>
#include <stdlib.h>
struct myfunc{
char* name;
};
int main() {
FILE* r = fopen("data.bin", "rb");
fread( w, sizeof(int), 30, r);
fread(&c, sizeof(myfunc),1,r);
for(int i=0; i < 30; i++){
cout<< i << ". " << w[i] << endl;
}
return 0;
}

Answer 1

Based on comment
the c I called from the struct myfunc and the w is the vector. so they are will be : int w[40]; myfunc c;
fread(&c, sizeof(myfunc),1,r);
will read one pointer's worth of data from file stream r into c. This will not be particularly useful as whatever address myfunc.name pointed at when the file was written will almost certainly be invalid when the file is read back.
Solution: Serialize myfunc.name when writing to the file and deserialize it when reading. Insufficient information is in the question to suggest how best to do this. I would store the string Pascal style and prepend the length of myfunc.name to make reading it back easier:
int len = strlen(myfunc.name);
fwrite(&len, sizeof(len), 1, outfile); // write length
fwrite(myfunc.name, len, 1, outfile); // write string
and read it
int len;
fread(&len, sizeof(len), 1, infile); // read length
myfunc.name = new char[len+1]; // size string with space for terminator
fwrite(myfunc.name, len, 1, infile); // read string
myfunc.name[len] = '\0'; // terminate string
Note the above code completely ignores endian and error handling.