How to read until EOF from cin in C++
The only way you can read a variable amount of data from stdin
is using loops. I've always found that the std::getline()
function works very well:
std::string line;
while (std::getline(std::cin, line))
{
std::cout << line << std::endl;
}
By default getline()
reads until a newline. You can specify an alternative termination character, but EOF is not itself a character so you cannot simply make one call to getline()
.
Using loops:
#include <iostream>
using namespace std;
...
// numbers
int n;
while (cin >> n)
{
...
}
// lines
string line;
while (getline(cin, line))
{
...
}
// characters
char c;
while (cin.get(c))
{
...
}
resource
You can do it without explicit loops by using stream iterators. I'm sure that it uses some kind of loop internally.
#include <string>
#include <iostream>
#include <istream>
#include <ostream>
#include <iterator>
int main()
{
// don't skip the whitespace while reading
std::cin >> std::noskipws;
// use stream iterators to copy the stream to a string
std::istream_iterator<char> it(std::cin);
std::istream_iterator<char> end;
std::string results(it, end);
std::cout << results;
}