The following code example is taken from the book
The C++ Standard Library - A Tutorial and Reference
by Nicolai M. Josuttis, Addison-Wesley, 1999
© Copyright Nicolai M. Josuttis 1999
#include <iterator>
#include <algorithm>
#include <fstream>
#include <iostream>
int countLines (std::istream& in);
int main (int argc, char* argv[])
{
int count;
if (argc == 1) {
// no argument => count lines of standard input
count = countLines(std::cin);
}
else {
// count number of lines of all files passed as argument
std::ifstream in;
count = 0;
for (int i=1; i<argc; ++i) {
in.open(argv[i]);
if (!in) {
std::cerr << "failed to open " << argv[1] << "\n";
}
else {
count += countLines(in);
in.close();
}
}
}
std::cout << count << std::endl;
}
int countLines (std::istream& in)
{
return std::count(std::istreambuf_iterator<char>(in),
std::istreambuf_iterator<char>(),
'\n');
}