First Time To Run C++ Program on Ubuntu 14.04

Question

What is the command to run the following simple C++ program?

#include <iostream>
using namespace std;

// main () is where program execution begins
int main()
{
  cout << "Hello World";        // prints Hello World

  return 0;
}

Answer 1

First you need to compile and link your program. Assuming the source code is saved in a file yourprog.cpp, you can do that using the GNU C++ compiler g++, for example

g++ -Wall -o yourprog yourprog.cpp

The resulting executable will be called yourprog and you can then run it using

./yourprog

Answer 2

Here's a way to use make to build and run your program without requiring any additional setup:

make CXXFLAGS='-Wall -Werror' hello_world && ./hello_world

But assuming you will continue developing, you will want to create a file called Makefile to streamline things further.

CXXFLAGS = -Wall -Werror
default: build
build: hello_world
run: build
<tab>./hello_world

Then you can build and run your program by typing:

make run

If you just want to see if your program compiles without error, type:

make

Other notes:

• The <tab> above should be created using the tab key.
• It is important to include -Wall -Werror. These flags prevent certain obvious programming bugs from being ignored by the compiler. That means less debugging work for the programmer.
• I advocate the use of the -s option with make. It eliminates (usually) unnecessary verbosity.
• One feature of make is that it doesn't recompile your program if it doesn't need to. This can be a nice time-saver if the program takes a long time to compile. This is especially useful if your project has more than one source (.cpp) file, since these can be compiled independently -- and even in parallel (simultaneously) with the -j option.

Answer 3

There's a nifty package called binfmtc that allows you to run C++ files as if if they were "scripts" -- not requiring an explicit compilation step.

Once the binfmtc package is installed, your source file needs a /*BINFMTCXX: ... header comment (see example) and mark the .cpp file as executable using chmod +x.

/*BINFMTCXX: -Wall -Werror
*/
#include <iostream>
using namespace std;

// main () is where program execution begins
int main()
{
  cout << "Hello World";        // prints Hello World

  return 0;
}

Setup steps:

$ sudo apt install binfmtc
$ chmod +x ./first-time-to-run-c-program-on-ubuntu-14-04.cpp

Running the "script":

$ ./first-time-to-run-c-program-on-ubuntu-14-04.cpp
Hello World

Answer 4

First, you save it to a file, most likely by pressing ctrl+s, then compile it. To compile it, run the following command:

g++ path/to/that/file.cpp -o path/to/output/file.out

Then just drag the output file to the terminal window to run it, because it is now an executable file.

You need to use g++ because c++ is a compiled language, meaning you need a compiler to compile it into machine code. This results in c++ being a faster language than others.

Answer 5

open a terminal and execute the following

1- g++ -o outfilename.bin source.cpp

2- ./outfilename.bin

that assumes the source file is source.cpp

Answer 6

• Open terminal by pressing Ctrl+Alt+t

• Install GNU C++ Compiler by running following command:

  sudo apt-get install g++  
  

• Now compile the cpp source file by running this command:

  g++ sourceFile.cpp -o anything  
  

• You can now run the file like this:

  ./anything