I am making a program that stores a default password that when entered correctly you can change it. Problem is when I enter the new password it doesn't save when I close and open the program.
#include<iostream>
#include<sstream>
using namespace std;
string inputC;
string yes = "yes";
string no = "no";
string password;
string input;
void correct()
{
cout << "Would you like to change the password?" << endl;
cin >> inputC;
if (inputC == yes)
{
cout << "Enter new password:" << endl;
cin >> password;
}
else
{
cout << "You now have access." << endl;
}
}
void enter()
{
cout << "Enter password: " << endl;
cin >> input;
if (input == password)
{
cout << "Correct" << endl;
correct();
}
else
{
cout << "Incorrect" << endl;
enter();
}
}
int main()
{
if (password.empty())
{
password = "password";
}
enter();
}
http://pastebin.com/zhKTW2FB
As far as I know, variables you create with code go to RAM Memory, so they are destroyed as soon as your programs finishes. In order to keep the new password, you should consider having it written in an external text file or database.
Related
I'd like to use yaml-cpp for storeing some config-values. In order to get in touch with yaml-cpp, I've written a method which creates a node (_config is from Type YAML::Node), put some values in it and write it into a file:
void write_config()
{
std::ofstream fout("/home/user/config.yaml");
_config["Foo"]["0"] = "0";
_config["Foo"]["1"] = "1";
_config["Foo"]["2"] = "2";
_config["Foo"]["3"] = "3";
_config["Foo"]["4"] = "4";
_config["Foo"]["5"] = "5";
fout << _config;
}
after running this Method, a valid yaml file is created:
Foo:
1: 1
3: 3
0: 0
5: 5
4: 4
2: 2
After that, I have created a Method to read the file and print some information:
void load_config()
{
_config = YAML::Node("/home/user/config.yaml");
cout << "_config: " << _config << endl;
cout << "doc.Type(): " << _config.Type() << "\n";
cout << "doc.size(): " << _config.size() << "\n";
for (const auto& kv : _config)
{
std::cout << kv.first.as<std::string>() << "\n"; // prints Foo
std::cout << kv.second.as<std::string>() << "\n"; // prints Foo
}
}
but the output is:
_config: /home/user/config.yaml
doc.Type(): 2
doc.size(): 0
could someone tell me why the Node is empty (size == 0) and how I can read the file properly?
Thank you in advance!
I've found my Mistake...
_config = YAML::Node("/home/user/config.yaml");
should be
_config = YAML::LoadFile("/home/user/config.yaml");
I am trying to save the data the user inputted inside a linked-list and then store those data inside a file so that I can retrieve them back when I enter the 2nd option(as per in the int main()). Unfortunately, after I wrote the data into the file and check back the file, I found out that my data is missing and the file is filled with garbage.so I cant retrieve the data back. Is there any solution to this problem?? Thank you.
#include<iostream>
#include<cstdlib>
#include<iomanip>
#include<fstream>
using namespace std;
fstream fp;
class List{
private:
struct node{
string name;
string surname;
int idNum;
string nationality;
int number;
node *next;
}nod;
node* head;
node* curr;
node* temp;
public:
List();
bool isEmpty(node *head){
if(head==NULL){
return true;
}
else
return false;
}
void AddNode(string addName,string addsurName,int addId,string addNation,int addNumber);
void insertAsFirst(string addName,string addsurName,int addId,string addNation,int addNum);
//void DeleteNode(int delData);
void printList();
void write_linky(string name,string surName,int idNum,string nation,int number);
void read_linky();
}lb;
List::List(){
head=NULL;
curr=NULL;
temp=NULL;
}
void List::insertAsFirst(string addName,string addsurName,int addId, string addNation,int addNum){
node *n = new node;
n->name=addName;
n->surname=addsurName;
n->idNum=addId;
n->nationality=addNation;
n->number=addNum;
n->next = NULL;
head = n;
//last = temp;
}
void List::AddNode(string addName,string addsurName,int addId,string addNation,int addNum){
if(isEmpty(head)){
insertAsFirst(addName,addsurName,addId,addNation,addNum);
}
else{
node* n = new node;
n->next=NULL;
n->name=addName;
n->surname=addsurName;
n->idNum=addId;
n->nationality=addNation;
n->number=addNum;
curr = head;
while(curr->next != NULL){
curr = curr->next;
}
curr->next = n;
}
}
void List::printList(){
curr=head;
cout << "\n\t\t\t\t CUSTOMER INFO" << endl << endl;
cout <<"NAME" << setw(20) << "SURNAME" << setw(20) << "ID NO. " << setw(20) << "NATIONALLITY" << setw(20) << "TELEPHONE" << endl << endl;
while(curr != NULL){
cout << curr -> name << setw(20) << curr -> surname << setw(20) << curr -> idNum << setw(20) << curr -> nationality << setw(20) << curr -> number << endl << endl;
curr=curr->next;
/*cout<<curr->number << endl;
cout<<curr->age << endl;
cout<<curr->idNum << endl;
cout<<curr->name<< endl;
cout<<curr->surname << endl;
cout<<curr->nationality << endl;
curr = curr->next;
}
*/
}
}
void List::write_linky(string name,string surName,int idNum,string nation,int number)
{
fp.open("Link.dat",ios::out|ios::app);
lb.AddNode(name,surName,idNum,nation,number);
lb.printList();
fp.write((char*)&nod,sizeof(node));
fp.close();
cout<<"\n\nThe Data Has Been Added ";
}
void List::read_linky(){
fp.open("Link.dat",ios::in);
while(fp.read((char*)&nod,sizeof(node)))
{
lb.printList();
//cout<<"\n\n=====================================================\n";
//getch();
}
fp.close();
//getch();
}
int main(){
List lb;
int idNum,number;
string name,surname,nationality;
char choice,ch;
cout<<"Please select your choice"<<endl;
cout<<"1.Book ticket"<<endl;
cout<<"2.view details"<<endl;
cin>>ch;
switch(ch){
case '1':
do{
cout<< "Enter name: ";
cin>>name;
cout<< "Enter surname: ";
cin>>surname;
cout<< "Enter identification number: ";
cin>>idNum;
cout<< "Enter your nationality: ";
cin>>nationality;
cout<< "Enter contact number: ";
cin>>number;
lb.write_linky(name,surname,idNum,nationality,number);
//lb.AddNode(number,age,idNum,name,surname,nationality);
cout<<"\n\nDo you want to add more entry?";
cin>>choice;
}while(choice=='y');
break;
case '2':
lb.read_linky();
break;
}
}
//lb.printList();
I've never done this but I'd guess string is a complex structure that doesn't lend itself to being written to disk like this. As a test change these to (say) char[255] and it might be happier.
I am writing simple chat in Qt + Apache Thrift but right now I need to face a problem with connecting multiple clients. On first sight everything looks good and I cannot find where the problem is.
Here is my server main.cpp:
int main(int argc, char **argv)
{
int port = 9090;
::apache::thrift::stdcxx::shared_ptr<UsersStorageHandler> handler(new UsersStorageHandler());
::apache::thrift::stdcxx::shared_ptr<TProcessor> processor(new UsersStorageProcessor(handler));
::apache::thrift::stdcxx::shared_ptr<TServerTransport> serverTransport(new TServerSocket(port));
::apache::thrift::stdcxx::shared_ptr<TTransportFactory> transportFactory(new TBufferedTransportFactory());
::apache::thrift::stdcxx::shared_ptr<TProtocolFactory> protocolFactory(new TBinaryProtocolFactory());
TSimpleServer server(processor, serverTransport, transportFactory, protocolFactory);
std::cout << "Users server started..." << std::endl;
std::cout << std::endl;
std::cout << std::endl;
server.serve();
return 0;
}
Here is my server handler.h:
class UsersStorageHandler : virtual public UsersStorageIf
{
public:
UsersStorageHandler();
int32_t subscribeUser(const std::string& username);
void unsubscribeUser(const int32_t userID);
private:
Users users;
};
Here is my server handler.cpp:
UsersStorageHandler::UsersStorageHandler()
{
srand(time(NULL));
}
int32_t UsersStorageHandler::subscribeUser(const std::string &username)
{
++idGenerator;
assert(username != "");
User user;
user.userId = idGenerator;
user.username = username;
user.colorR = (rand() % 255) + 0;
user.colorG = (rand() % 255) + 0;
user.colorB = (rand() % 255) + 0;
user.colorA = 0;
users[idGenerator] = user;
std::cout << "NEW USER CONNECTED" << std::endl;
std::cout << "==================" << std::endl;
std::cout << "Username:\t" << user.username << std::endl;
std::cout << "User ID:\t" << user.userId << std::endl;
std::cout << "User R:\t" << user.colorR << std::endl;
std::cout << "User G:\t" << user.colorG << std::endl;
std::cout << "User B:\t" << user.colorB << std::endl;
std::cout << "User A:\t" << user.colorA << std::endl;
std::cout << "==================" << std::endl;
std::cout << "CURRENT USERS COUNT:\t" << users.size() << std::endl;
std::cout << std::endl;
std::cout << std::endl;
/*
* SEND TO CLIENT INFO ABOUT NEW USER HERE
*/
return idGenerator;
}
void UsersStorageHandler::unsubscribeUser(const int32_t userID)
{
auto index = users.find(userID);
assert(index != users.end());
users.erase(index);
std::cout << "USER DISCONNECTED" << std::endl;
std::cout << "=================" << std::endl;
std::cout << "USER WITH ID " << userID << " ERASED" << std::endl;
std::cout << "USERS COUNT:\t" << users.size() << std::endl;
std::cout << std::endl;
std::cout << std::endl;
/*
* SEND TO CLIENT INFO ABOUT NEW USER HERE
*/
}
And right here is a method for connect to the server in client app:
void MainWindow::connectToServers(const std::string &ip, const uint32_t &port, const std::string &nick)
{
m_usersServerIP = ip;
m_usersServerPort = port;
try
{
::apache::thrift::stdcxx::shared_ptr<TTransport> socket(new TSocket(m_usersServerIP, m_usersServerPort));
::apache::thrift::stdcxx::shared_ptr<TTransport> transport(new TBufferedTransport(socket));
::apache::thrift::stdcxx::shared_ptr<TProtocol> protocol(new TBinaryProtocol(transport));
m_usersServerClient = std::make_shared<UsersStorageClient>(protocol);
transport->open();
m_clientID = m_usersServerClient.get()->subscribeUser(nick);
QMessageBox::information(this, "Connected",
"You are connected "
"with users server");
createAndRegisterUsersServerReactor();
activateChatScreen();
}
catch (const std::exception &e)
{
qDebug() << e.what();
}
qDebug() << "ID FROM SERVER:\t" << m_clientID;
}
As far as I checked right now it is working like this:
Created two instances of client app. In one instance fill nickname, ip, port and clicked connect (connectToServers method). Client connected. In another instance done the same but after clicked connected ... nothing happens. App freezes at this line:
m_clientID = m_usersServerClient.get()->subscribeUser(nick);
After closing first client, second one connects to the server.
A TSimplerServer supports a single connection. You should try using TThreadedServer to support multiple simultaneous clients.
As Chris mentioned above either make a Threaded server to server multiple requests simultaneously. For me I have created a non-blocking server as below to be able to serve multiple clients in async manner for loose coupling.
public static void start(dataClass configData, String env, int port) throws TTransportException {
TNonblockingServerTransport transport = new TNonblockingServerSocket(port);
TNonblockingServer.Args nBlockServer = new TNonblockingServer.Args(transport);
ccmProviderServiceImpl impl = new ccmProviderServiceImpl(configData, env);
Processor<ccmProviderServiceImpl> processor = new ccmProviderService.Processor<>(impl);
TServer server = new TNonblockingServer(nBlockServer.processor(processor));
//custom event handling for tracking
ccmServerEventHandler cse = new ccmServerEventHandler();
server.setServerEventHandler(cse);
server.serve();
}
I'm using boots's property_tree library. I'm looking for a way to get a child node from a ptree object, but return an empty ptree if failed. I came across a nice example in property_tree/examples/empty_ptree_trick.cpp:
void process_settings(const std::string &filename)
{
ptree pt;
read_info(filename, pt);
const ptree &settings = pt.get_child("settings", empty_ptree<ptree>());
std::cout << "\n Processing " << filename << std::endl;
std::cout << " Setting 1 is " << settings.get("setting1", 0) << std::endl;
std::cout << " Setting 2 is " << settings.get("setting2", 0.0) << std::endl;
std::cout << " Setting 3 is " << settings.get("setting3", "default") << std::endl;
}
which does exactly what I need. The problem is that the compiler complains that empty_ptree() function is not a member of boost:property_tree. Any ideas where empty_ptree() is?
I'm using boost 1.44 on VS2010.
I have just blown a full day trying to answer that question!
This was my solution. Firstly I used pointers, and not references as you have to initialize them immediately. Then I just caught the exception and added a new ptree.
using namespace boost::property_tree;
ptree r_pt;
ptree *c_pt;
read_xml( "file.xml" , r_pt);
try {
c_pt = &(r_pt.get_child( "example" ));
}
catch (ptree_bad_path) {
c_pt = &(r_pt.put_child( "example", ptree() ));
}
std::cout << "Setting 1 is " << c_pt.get("setting1", 0) << std::endl;
From what I could pick up they expect us to use the boost::optional type. But I'm just a beginner..
EDIT
I just found the implementation of empty_ptree<>.
template<class Ptree>
inline const Ptree &empty_ptree()
{
static Ptree pt;
return pt;
}
I think you can just add this to your code and use it as described in the empty_ptree_trick.cpp, but I am sticking with my solution for now untill I find out how its actually supposed to be done.
void process_settings(const std::string &filename)
{
ptree pt;
read_info(filename, pt);
const ptree &settings = pt.get_child("settings", ptree());
std::cout << "\n Processing " << filename << std::endl;
std::cout << " Setting 1 is " << settings.get("setting1", 0) << std::endl;
std::cout << " Setting 2 is " << settings.get("setting2", 0.0) << std::endl;
std::cout << " Setting 3 is " << settings.get("setting3", "default") << std::endl;
}
Note, that will prevent throwing an instance of 'boost::wrapexceptboost::property_tree::ptree_bad_path'
I have a class (contains a few scalar values and a vector of floats) and I want to read and write an instance as the value of another map.
// write
out << YAML::Key << "my_queue" << YAML::Value << my_queue;
// read (other code cut out...)
for (YAML::Iterator it=doc.begin();it!=doc.end();++it)
{
std::string key, value;
it.first() >> key;
it.second() >> value;
if (key.compare("my_queue") == 0) {
*it >> my_queue;
}
}
Writing this class works perfectly, but I can't seem to read it no matter what I do. It keeps throwing an InvalidScalar.
Caught YAML::InvalidScalar yaml-cpp: error at line 20, column 13: invalid scalar
and this is that the output (written with yaml-cpp without it reporting any errors) looks like:
Other Number: 80
my_queue:
size: 20
data:
- 3.5
- -1
- -1.5
- 0.25
- -24.75
- -5.75
- 2.75
- -33.55
- 7.25
- -11
- 15
- 37.5
- -3.75
- -28.25
- 18.5
- 14.25
- -36.5
- 6.75
- -0.75
- 14
max_size: 20
mean: -0.0355586
stdev: 34.8981
even_more_data: 1277150400
The documentation seems to say this is supported usage, a nested map, in this case with a sequence as one of the values. It complains about it being an InvalidScalar, even though the first thing I do it tell it that this is a map:
YAML::Emitter& operator << ( YAML::Emitter& out, const MeanStd& w )
{
out << YAML::BeginMap;
out << YAML::Key << "size";
out << YAML::Value << w.size();
out << YAML::Key << "data";
out << YAML::Value << YAML::BeginSeq;
for(Noor::Number i=0; i<w.size(); ++i) {
out << w[i];
}
out << YAML::EndSeq;
out << YAML::Key << "max_size";
out << YAML::Value << w.get_max_size();
out << YAML::Key << "mean";
out << YAML::Value << w.mean();
out << YAML::Key << "stdev";
out << YAML::Value << w.stdev();
out << YAML::EndMap;
return out;
}
Does anyone see a problem with this?
When you're reading the YAML:
std::string key, value;
it.first() >> key;
it.second() >> value; // ***
if (key.compare("my_queue") == 0) {
*it >> my_queue;
}
The marked line tries to read the value of the key/value pair as a scalar (std::string); that's why it tells you that it's an invalid scalar. Instead, you want:
std::string key, value;
it.first() >> key;
if (key.compare("my_queue") == 0) {
it.second() >> my_queue;
} else {
// ...
// for example: it.second() >> value;
}
YAML::Node internalconfig_yaml = YAML::LoadFile(configFileName);
const YAML::Node &node = internalconfig_yaml["config"];
for(const auto& it : node )
{
std::cout << "\nnested Key: " << it.first.as<std::string>() << "\n";
if (it.second.Type() == YAML::NodeType::Scalar)
{
std::cout << "\nnested value: " << std::to_string(it.second.as<int>()) << "\n";
}
if (it.second.Type() == YAML::NodeType::Sequence)
{
std::vector<std::string> temp_vect;
const YAML::Node &nestd_node2 = it.second;
for(const auto& it2 : nestd_node2)
{
if (*it2)
{
std::cout << "\nnested sequence value: " << it2.as<std::string>() << "\n";
temp_vect.push_back(it2.as<std::string>());
}
}
std::ostringstream oss;
std::copy(temp_vect.begin(), temp_vect.end(),
std::ostream_iterator<std::string>(oss, ","));
std::cout << "\nnested sequence as string: " <<oss.str() << "\n";
}
}
if (it2.second.Type() == YAML::NodeType::Map)
{
// Iterate Recursively again !!
}