Sublime Text: Always run a single file in a project no matter what is focused

When I program, I often try to split up my code into modules. This requires that I use different files. However, I also want to run my code from a “main” or a “master” file as well. It’s pretty annoying in Sublime Text, or any text editor, to have to switch to your main file to run your project.

I’ve talked about how to do this in TextMate but how can you pull this off in Sublime Text? Let me show you how.

  1. Create a Sublime Text project for your program. You can do this by using the menu Project > Save Project As…”.
  2. Open the settings for your project using the menu Project > Edit Project.
  3. You’ll get a mostly empty text window. Modify this window to include a build definition, such as the following one for Python:
    • "build_systems": [
          "name": "PyProj",
          "cmd": ["python", "-u", "$file"],
          "file_regex": "^[ ]*File \"(...*?)\", line ([0-9]*)",
          "selector": "source.python"
  4. Modify the line with “cmd” and change “$file” to the master file you always want to run. For example, if your main file is called pyproj.py, then change it to pyproj.py.
Add the "build_systems" JSON field in your project settings file, accessible through the Project menu > Edit project.

Add the “build_systems” JSON field in your project settings file, accessible through the Project menu > Edit project.

That’s it! While you’re editing your project settings, you can make other customizations as well as you see fit.

Obviously, this isn’t limited to just setting a file to be run no matter what file you’re focused on. You could use this to add command-line arguments to a single project, to run project-specific scripts for building and testing, or to otherwise customize the way the “Control-B” (Command-B on Mac OS X) works when you are running the project. You can essentially define your own build system on a per-project basis in a project file’s “build_systems” section and use any information in Sublime Text’s build system documentation to do so. Unfortunately, the build system documentation doesn’t really describe this because it’s focused more toward Package development.

For more information about how project settings work, look at Sublime Text’s documentation for build systems and for projects!


TextMate and Running a Master File

Many people find my blog searching about how to make their multi-file LaTeX projects build in TextMate.

It’s worth nothing that the TM_MASTER_FILE works for almost any programming project, not just LaTeX. So, if you’re working on a Python or a Ruby project and have a main file that you want to run, set the TM_PROJECT_MASTER to point to that and save yourself some effort. Here’s a reminder on how to do that.

  1. Open your project file (or create one if you don’t have one).
  2. De-select any selected files in the TextMate drawer by clicking on empty space.
  3. Click on the “i” in the bottom-right corner of the drawer.
  4. Add a variable named TM_PROJECT_MASTER.
  5. Set the value to the name of your main file (in my Ludum Dare game, it was painterscat.py

Now your “run” ⌘r shortcut will always run your main file with minimal hassle!