Question

I’m trying to write a sh script to make a rails apps, however due to different conflict, I need to modify my environment.rb file to comment out the rails version. So my question is how do I had ‘#’ to line 8 of environment.rb?

Answer 1

There are many ways, but sed is the first hammer that came to mind:

sed 's/^\(RAILS_GEM_VERSION.*\)$/# \1/' -i '.backup' config/environment.rb

Or even in ruby:

ruby -pi  -e 'print "# " if $_ =~ /^RAILS_GEM_VERSION/' config/environment.rb