You would want to break this down into several smaller reads rather than having the one big read like I wrote, that was just there to illustrate. I also made sure that it wouldn't compile for you to read this part. There is an obvious problem in if you are trying to read a file which is too large then this will not be able

Well, work as in this will copy the file's contents exactly. Is guaranteed to work, and this is pretty much the basics of the file copy routine. WriteFile(target, buffer, li.QuadPart, /*other params*/) Target = CreateFile(target, GENERIC_WRITE, /*other params*/) ReadFile(source, buffer, li.QuadPart, /*other params*/) Source = CreateFile(source, GENERIC_READ, /* Other params*/) If you are using C, then the C standard should guarantee the exact same things. The standard also guarantees that if you copy an object to an array of char or unsigned char large enough to hold the object, and then copy back the array to a new object, then what is in the new is guaranteed to be an exact copy of the original object. So the char type is defined to be the same size as a byte. The C++ standard defines a byte to be at least large enough to contain any member of the basic execution character set, and the char type is defined in the same Special thanks to papagaga and Incomputable for helping me with this topic via can just use ReadFile to read it into a void * buffer, and then use WriteFile to write it back out to file.Īlso, the C++ standard guarantees that you can use char for this kind of thing. Reading a dataset with unknown, mixed data types is another beast and beyond the scope of this article, but see this code review for possible solutions.

Extending this to read/write a dataset of only doubles or only strings should be fairly straight-forward. So far we’ve seen how to read and write datasets with integer values only. This program reads our previously created CSV files and writes each dataset to a new file, essentially creating copies of our original files. #include #include #include #include // std::pair void write_csv ( std :: string filename, std :: vector > dataset )

How to convert a file into map in c++