{
  "cells": [
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": "## Creating a custom magic command in an IPython extension"
    },
    {
      "cell_type": "code",
      "execution_count": 1,
      "metadata": {},
      "outputs": [],
      "source": "from IPython.core.magic import register_cell_magic"
    },
    {
      "cell_type": "code",
      "execution_count": 2,
      "metadata": {},
      "outputs": [],
      "source": "@register_cell_magic\ndef cpp(line, cell):\n    \"\"\"Compile, execute C++ code, and return the standard output.\"\"\"\n\n    # We first retrieve the current IPython interpreter instance.\n    ip = get_ipython()\n\n    # We define the source and executable filenames.\n    source_filename = '_temp.cpp'\n    program_filename = '_temp'\n\n    # We write the code to the C++ file.\n    with open(source_filename, 'w') as f:\n        f.write(cell)\n\n    # We compile the C++ code into an executable.\n    compile = ip.getoutput(\"g++ {0:s} -o {1:s}\".format(\n        source_filename, program_filename))\n\n    # We execute the executable and return the output.\n    output = ip.getoutput('./{0:s}'.format(program_filename))\n\n    print('\\n'.join(output))"
    },
    {
      "cell_type": "code",
      "execution_count": 3,
      "metadata": {},
      "outputs": [
        {
          "data": {
            "text/plain": "Hello world!"
          },
          "execution_count": 3,
          "metadata": {},
          "output_type": "execute_result"
        }
      ],
      "source": "%%cpp\n#include<iostream>\nint main()\n{\n    std::cout << \"Hello world!\";\n}"
    }
  ],
  "metadata": {},
  "nbformat": 4,
  "nbformat_minor": 0
}