Applying syntax in Sublime based on the first file line

In vim, you can add a comment at the top of files to set the syntax, e.g.:

# vim: syntax=ruby

In SublimeText there are many ways to detect syntax, one interesting approach I’ve recently found useful is to match on the top line in the file. For example, with Puppet there is a file called Puppetfile, it has no extension but it’s really Ruby syntax, so it’s useful to add linting incase you miss something simple like a , and break deployments.

I use a plugin called ApplySyntax making it easy to apply syntax options to files, I believe you can do this in the languages syntax without the plugin but YMMV:

{
...
  // Put your custom syntax rules here:
  "syntaxes": [
    {
    "syntax": [ "Ruby/Ruby" ],
    "rules": [
            { "first_line": ".*syntax=ruby.*" }, # To match on the first line in the file
            { "file_path": "^Puppetfile$"} # Or match on the file name or path itself
        ]
    }
  ]
...
}