I'm programming in C++ with Netbeans 8.2 at school, these computers have Ubuntu 14.04 and gcc-4.3.
The cout randomly works altought it doesn't send any errors in the log.
Every computer here has the same problem.
main.cpp:
#include <cstdlib>
#include <iostream>
using namespace std;
int main(int argc, char** argv) {
cout << "Hello World!" << endl;
return 0;
}
Posible (and expected) output:
Hello World!
RUN FINISHED; exit value 0,; real time: 0ms; user: 0ms; system: 0ms
Other posible output:
RUN FINISHED; exit value 0,; real time: 0ms; user: 0ms; system: 0ms
Sometimes the compiler prints out and finish without being noticed. So you can use cin to check if that is happening to you.
#include <cstdlib>
#include <iostream>
using namespace std;
int main(int argc, char** argv) {
cout << "Hello World!" << endl;
int test;
cin >> test;
return 0;
}
Here the compiler will wait for you to enter a value, so you will have plenty of time to see your output.
I solved this going to Project Properties -> Run -> Console Type -> Standard output
Related
#include <iostream>
#include <stdio.h>
#include <stdlib.h>
#include <cstdlib>
using namespace std;
int main() {
string line;
cout << "HW\n";
getline(cin,line);
cout << "Your line is - " << line << "\n";
system("pause");
return 0;
}
I want to do gui to factorio headless server by myself so i need to exec few bash scripts. I think i need function system() to that ?
I think I got problem with lib path. Please don't blame to wrong installed vcpkg. Paths is :
/opt/factorio/bin/x64/vcpkg/installed
/usr/include/c++/9/x86_64-redhat-linux
/usr/include/linux
/usr/include/c++/9/tr1
Command system() not found says Visual Studio.
system("pause"); is meant to be used only on Windows. It runs the Windows command-line "pause" program and waits for that to terminate before it continues execution of your program. That's why it's a bad practice to use it in your code, no matter if you are running your code on Windows or Linux.
Here is a better way you can achieve the same result:
#include <iostream>
using namespace std;
int main() {
do {
cout << '\n' << "Press the Enter key to continue.";
} while (cin.get() != '\n');
return 0;
}
instead of:
#include <iostream>
using namespace std;
int main() {
system("pause");
return 0;
}
I installed codellite 7.0 yesterday and have been trying to work with it. But there seem to be some problem. I cannot run any code.
For now code is pretty simple.
#include <stdio.h>
int main(int argc, char **argv)
{
printf("hello world\n");
return 0;
}
however, it returns following and output is blank with Press any key to continue
Current working directory: D:\ .....
Running program: le_exec.exe ./1
Program exited with return code: 0
Your program is running fine, the only problem is that after the printf the program returns 0 and shuts down immediately, it does run and print out "hello world", you just don't have the time to see it.
To make the program wait for user input so that you can see the output use cin.get() :
#include <stdio.h>
#include <iostream>
int main(int argc, char **argv)
{
printf("hello world\n");
std::cin.get();
return 0;
}
I am new to C++. I downloaded and run Dev-C++ and I write and run F9 this:
#include <iostream>
using namespace std;
int main()
{
cout << "Hello, world!";
return 0;
}
But no "Hello, world!" is printed, why?
Many IDE users have this problem. The program runs but it closes before you can see its results on the screen. One portable fix is to add this at the bottom of main before you return:
std::cin.get();
That way it will wait for you to enter some text before it exits.
#include <iostream>
using namespace std;
int main()
{
cout << "Hello, world!";
getchar();
return 0;
}
Add getchar() at the end of your program as a simple "pause-method" as consoles seems to close so fast, so you need to "delay" to see your console.
The output is printed to a terminal, and you don't have a newline etc.... very unlikely that you will see it, so
Add a newline to the output
make sure you have time to read the output before the terminal window closes (add a sleep or something)
Don't use using namespace as that is a bad practice and will lead to trouble in your programming.
So like;
#include <iostream>
#include <unistd.h>
int main()
{
std::cout << "Hello, world!" << std::endl;
sleep(2);
return 0;
}
When using this simple snippet
int main(int argc, char** argv) {
cout << "Joris" << endl;
return 0;
}
I get randomly this result:
Joris
or
RUN FAILED.
Behaviour occurs with internal terminal or standard output in project settings.
I run under openSUSE Netbeans 7.0.1 with GCC.
Do you get the same result with the following?
#include <iostream>
int main()
{
std::cout << "Joris" << std::endl;
return 0;
}
Is there a C++ equivalent to Python's time.sleep()?
Use boost::this_thread::sleep
// sleep for 5 seconds
boost::this_thread::sleep(boost::posix_time::seconds(5));
The following code will sleep for 10 milliseconds.
boost::this_thread::sleep(boost::posix_time::milliseconds(10))
Refer to boost::posix_time::time_duration for more ways to construct the duration.
I'm not aware of any portable function, but mainstream OSes have usleep for *nix and Sleep for Windows.
Please note that the code above was tested on Code::Blocks 12.11 and Visual Studio 2012
on Windows 7.
For forcing your programme stop or wait, you have several options :
sleep(unsigned int)
The value has to be a positive integer in millisecond.
That means that if you want your programme wait for 2 second, enter 2000.
Here's an example :
#include <iostream> //for using cout
#include <stdlib.h> //for using the function sleep
using namespace std; //for using cout
int main(void)
{
cout << "test" << endl;
sleep(5000); //make the programme waiting for 5 secondes
cout << "test" << endl;
sleep(2000); // wait for 2 secondes before closing
return 0;
}
If you wait too long, that probably means the parameter is in second. So change it like that :
sleep(5);
For those who get error message or problem using sleep try to replace it by _sleep or Sleep especially on Code::Bloks.
And if you still getting probleme, try to add of one this library on the biggining of the code.
#include <stdio.h>
#include <time.h>
#include <unistd.h>
#include <dos.h>
#include <windows.h>
system("PAUSE")
A simple "Hello world" programme on windows console application would probably close before you can see anything. That the case where you can use system("Pause").
#include <iostream>
using namespace std;
int main(void)
{
cout << "Hello world!" << endl;
system("PAUSE");
return 0;
}
If you get the message "error: 'system' was not declared in this scope" just add
the following line at the biggining of the code :
#include <cstdlib>
cin.ignore()
The same result can be reached by using cin.ignore() :
#include <iostream>
using namespace std;
int main(void)
{
cout << "Hello world!" << endl;
cin.ignore();
return 0;
}
cin.get()
example :
#include <iostream>
using namespace std;
int main(void)
{
cout << "Hello world!" << endl;
cin.get();
return 0;
}
getch()
Just don't forget to add the library conio.h :
#include <iostream>
#include <conio.h> //for using the function getch()
using namespace std;
int main(void)
{
cout << "Hello world!" << endl;
getch();
return 0;
}
You can have message telling you to use _getch() insted of getch