用string接收讀取內容

#include <string>
#include <fstream>
#include <streambuf>

std::ifstream t("file.txt");
std::string str((std::istreambuf_iterator<char>(t)),
                 std::istreambuf_iterator<char>());

std::ifstream t("file.txt");
std::stringstream buffer;
buffer << t.rdbuf();
 

ifstream ifs ("filename.txt");
string s;
getline (ifs, s, (char) ifs.eof());

用char[]接收讀取內容

std::ifstream t;
int length;
t.open("file.txt");      // open input file
t.seekg(0, std::ios::end);    // go to the end
length = t.tellg();           // report location (this is the length)
t.seekg(0, std::ios::beg);    // go back to the beginning
buffer = new char[length];    // allocate memory for a buffer of appropriate dimension
t.read(buffer, length);       // read the whole file into the buffer
t.close();      
 

參考地址：

https://stackoverflow.com/questions/2602013/read-whole-ascii-file-into-c-stdstring