Is there any way for me to force a check for Ruby 1.9 in a file that I require so I get a good error message before the main file is parsed?
$ rvm use 1.9.2-head
Using ruby 1.9.2 head
$ ruby app.rb
with apple,butter,flour we can make a great pie
here is my app
bye
$ rvm use 1.8.7
Using ruby 1.8.7 p249
$ ruby app.rb
app.rb:4: syntax error, unexpected tINTEGER, expecting tSTRING_CONTENT or tSTRING_DBEG or tSTRING_DVAR or tSTRING_END
make_pie apple:2, butter:1, flour:4
^
Here's a good blog post: http://blog.aizatto.com/2007/05/30/what-version-of-ruby-am-i-using/
However the technique doesn't get a chance to work if there is a syntax error in the file in 1.8.x that works in 1.9