How do you open a file in C

Question

I want to open a file in C++ for reading.

I need to be able to accomplish that for the following reasons:

text files, which would need some kind of read line function binary files, which would allow raw data to be read into a char* buffer

Answer 1

Depending on your requirements, there are three options. You could call fopen/fread/fclose in C, or you could use the C++ fstream facilities (ifstream/ofstream), or if you're using MFC, you could use the CFile class, which offers methods to do actual file operations.

All of them are adequate for text and binary, but none have readline capabilities. In that instance, you'd probably use the fstream classes (fstream.h) and the stream operators ( and >>) or the read function to read/write text blocks:

int nsize = 10;

std::vector somedata(nsize);

ifstream myfile;

myfile.open("");

myfile.read(somedata.data(), nsize);

myfile.close();

It's worth noting that if you're using Visual Studio 2005 or later, conventional fstream might not be accessible (there's a new Microsoft solution that's somewhat different but does the same thing).

Answer 2

Depending on your requirements, there are three options. You could call fopen/fread/fclose in C, or you could use the C++ fstream facilities (ifstream/ofstream), or if you're using MFC, you could use the CFile class, which offers methods to do actual file operations.

All of them are adequate for text and binary, but none have readline capabilities. In that instance, you'd probably use the fstream classes (fstream.h) and the stream operators ( and >>) or the read function to read/write text blocks:

int nsize = 10;

std::vector somedata(nsize);

ifstream myfile;

myfile.open("");

myfile.read(somedata.data(), nsize);

myfile.close();

It's worth noting that if you're using Visual Studio 2005 or later, conventional fstream might not be accessible (there's a new Microsoft solution that's somewhat different but does the same thing).