#include <iostream>
#include <vector>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <string.h>

int main(int argc, char** argv) {

	if (argc < 2) {
		std::cout << "invalid input" << std::endl;
		return 1;
	}

	const std::string fpath = argv[1];

	struct stat st;
	int ret = stat(fpath.c_str(), &st);
	if (ret != 0) {
		std::cout << "failed statting: " << fpath << ", " << strerror(errno) << std::endl;
		return 1;
	}

	FILE* fin = fopen(fpath.c_str(), "r");
	if (!fin) {
		std::cout << "Failed opening: " << argv[1] << std::endl;
		return 1;
	}

	char* buf = new char[st.st_size];
	memset(buf, 0, st.st_size);
	size_t r = fread(buf, 1, st.st_size, fin);
	fclose(fin);

	if (r != st.st_size) {
		std::cout << "read: " << r << "/" << st.st_size << " bytes" << std::endl;
		delete[] buf;
		return 1;
	}

	std::vector<std::string> lines;
	std::string l;

	for (size_t t = 0; t < st.st_size; ++t) {
		if (buf[t] == '\n') {
			lines.push_back(l);
			l = std::string();
			continue;
		}

		l += buf[t];
	}

	std::cout << "there are: " << lines.size() << " lines" << std::endl;

	delete[] buf;
	return 0;
}