Use “#!/usr/bin/env hbcxx” to make C++ source code executable

#! C++
#! C++I normally write some kind of personal toy during the holiday season. For example last year I wrote a toy fibre scheduler to go with a microcontroller project I was working on. This year however I’ve cooked up something and can’t quite decide if its a great idea, a pointless idea or a stupid idea. One thing is clear however, to find out which of the three possibilities it is, this bit of code needed packaging up properly as a product and shared with the wider world. Basically hbcxx uses the Unix #!/path/to/interpreter technique to make C++ source code directly executable.I’ve been taking a new look at C++. There is a palpable sense of “buzz” in the C++ community as they realize that, with C++11, they are sitting on something pretty special. The advocacy from the presenters at Going Native this year was remarkably effective (although if you take my advice you won’t watch Scott Meyer’s brilliant Effective C++14 Sampler until you know what std::move is for).
Quoting Bjarne Stroustrup: Surprisingly, C++11 feels like a new language. Considering its source it is not at all surprising that this quote is absolutely on the money: modern C++, meaning C++11 or later, does feel like another language. This is not because the language has been changed massively but because the new features encourage a different, and slightly higher level way to think about writing C++. It’s faster and more fun, supports lambdas, has tools to simplify memory management and includes regular expressions out-of-the-box.I was actually pretty amazed to see regular expressions in the standard C++ libraries, so that coupled with humane memory management (albeit humanity where you have to explicitly opt-in) and the auto keyword really got me thinking differently about writing C++. auto even encouraged me to write a template (generic programming is so much easier when you don’t have to explicitly declare the type of every expression). All this and without losing type safety…So my great/pointless/stupid idea (delete whichever is inappropriate) is a tool to keep things fast and fun by putting off the moment you have to write a build system and install script. For simple programs, especially for quick and dirty personal toys and scripts, the day you have to write a proper build system may never come. You no longer want the distraction of making a separate directory and a Makefile and you’ll find that pkg-config to just work.Instead I just copy your C++ source code into $HOME/bin. Try it. It works.Features include:

  • Automatically uses ccache to reduce program startup times (for build avoidance).
  • Enables -std=c++11 by defualt.
  • Parses #include directives to automatically discover and compile other source code files.
  • Recognises the inclusion of boost header files and, where needed automatically links the relevant boost library.
  • pkg-config integration.
  • Direct access to underlying compiler flags (-O3, -fsanitize=address, -g).
  • Honours the CXX environemnt variable to ensure clean integration with tools such as clang-analyzer’s scan-build.

To learn more about hbcxx take a look at:

Then have fun.