Question

I have this code that works fine:

FILE *fp;
fp = fopen(filename.c_str(), "rb");
char id[5];
fread(id,sizeof(char),4,fp);

now I’ve changed something in my architecture, and instead the filename as fullpath of the file I have a char pointer that contains the data of the file.. so I don’t need to read (fopen, etc..) but only to read the char* buffer…
how can I do this?
thanks in advance

Answer 1

If I’m understanding your question correctly, you want to access a four character ID somewhere in the middle of your buffer. The easiest way to do this is just to copy the data into a new buffer and add a NULL terminator.

size_t index = 0;
// ...
char id[5];
memcpy(id, &myData[index], 4);
id[4] = '\0';
index += 4;

You can then read through your buffer sequentially by updating the index value every time you read something.