Hello. I have some questions regarding file manipulation with Win32 API functions.
I want to make a header that is the size of INT and memories in it the number of USERS (for example);
After that I want to make a vector that contains the adresses of every USER and another vector that contains the size of the USER;
Lets assume that I will Create the file with 100 entries.
The created file would be like:
(INT) first 4 bytes; (the value of this one is 100 as 100 USERS)
INT[100] a vector with 100 ints and every element containing an adress of the USER (first element of the vector is the first user adress etc..)
INT[100] a vector with 100 ints and every element containing an sizeof the USER (first element of the vector is the first user size etc..)
WriteFile(test_usernames, (char*)&users_number, sizeof(int), &dwBytesWritten11, NULL);
WriteFile(test_usernames, (char*)&adrresses[0], sizeof(int)*users_number, &dwBytesWritten11, NULL);
WriteFile(test_usernames, (char*)&sizes[0], sizeof(int)*users_number, &dwBytesWritten11, NULL);
SetFilePointer(test_usernames,sizeof(int) , NULL, FILE_BEGIN);
WriteFile(test_usernames, (char*)sizes[0], sizeof(int), &dwBytesWritten11, NULL);
1. If I write DATA1 that contains 4bytes for example and I want to return later and write exactly after that DATA1 i set the FilePointer to the sizeof(DATA1 ) of the sizeof(DATA1 ) + 1?
2. WriteFile( ... (char*)users[0] , sizeof(int)*users_number ) will start to write from element 0 to the last element of the vector because of the sizeof that tells where to stop or because the & operator? What about if I want only to write a single element to the file (like in the last line of the code) it will be ok (char*)sizes[0] or (char*)&sizes[0] with smaller size to write specified in the WriteFile argument ?
