#include <iostream>
#include <cstdio>

int main(int argc, char** pp_args)
{
	if(argc == 1)
	{
		std::cout << "Usage: addnewline file1 file2 file3 ..." << std::endl;
		return 0;
	}
	else
	{
		int numErrors = 0;

		for(int i = 1; i < argc; ++i)
		{
			FILE* p_file = fopen(pp_args[i], "rb");
			if(!p_file)
			{
				std::cerr << "Couldn't open file " << pp_args[i] << std::endl;
				++numErrors;
				continue;
			}

			std::cout << pp_args[i] << ": ";

			fseek(p_file, 0, SEEK_END);
			long fileSize = ftell(p_file);

			bool addNewLine = fileSize == 0;
			if(fileSize)
			{
				fseek(p_file, fileSize - 1, SEEK_SET);
				int ch = fgetc(p_file);
				addNewLine = ch != '\n';
			}

			fclose(p_file);

			if(addNewLine)
			{
				p_file = fopen(pp_args[i], "ab");
				fputc('\n', p_file);
				fclose(p_file);

				std::cout << "added newline" << std::endl;
			}
			else
			{
				std::cout << "OK" << std::endl;
			}
		}

		return numErrors;
	}
}