gistfile1.cpp

 #include <algorithm>
 #include <vector>

/** check if name names a valid path
 *
 */
inline bool path_exists(const std::string& name) {
 
	struct stat buffer;   
	
	return (stat (name.c_str(), &buffer) == 0); 

}


/** check if the string s is a positive
 * integer
 */
bool is_positive_number(const std::string& s)
{

    if (!s.empty() && std::find_if(s.begin(), 
        s.end(), [](char c) { return !std::isdigit(c); }) == s.end()) {

    	return (std::stoi(s) > 0);

    }

    return false;
}

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

	std::cout << argc << "\t" << !is_positive_number(argv[3]) << std::endl;

	if (argc != 5 || !is_positive_number(argv[3]) || !is_positive_number(argv[4]) ||
		!path_exists(argv[1] + 1) || !path_exists(argv[2] + 1)) {

		std::cout << "usage: CachingFileSystem rootdir mountdir numberOfBlocks blockSize\n";

		return FUNC_FAIL;

	}
	
	NumOfBlocks = std::stoi(argv[3]); // TODO: make extern
	BlockSize = std::stoi(argv[4]);