Modernize usage of File.dirname(__FILE__) to support symlinks

[pcbeard]

I tried to create a symlink to ftpd/bin/ftpdrb, but this broke the relative path name loading code:

unless $:.include?(File.dirname(__FILE__) + '/../lib')
  $:.unshift(File.dirname(__FILE__) + '/../lib')
end

This stack overflow article suggests using __dir__ as the equivalent of File.dirname(File.realpath(__FILE__)) which is precisely what's needed to compute the proper relative paths. Here's a patch:

diff --git a/bin/ftpdrb b/bin/ftpdrb
index 4513597..dcd222d 100755
--- a/bin/ftpdrb
+++ b/bin/ftpdrb
@@ -2,8 +2,8 @@
 #
 # Ftpd is a pure Ruby FTP server library. CLI version
 #
-unless $:.include?(File.dirname(__FILE__) + '/../lib')
-  $:.unshift(File.dirname(__FILE__) + '/../lib')
+unless $:.include?(__dir__ + '/../lib')
+  $:.unshift(__dir__ + '/../lib')
 end
 
 require 'ftpd'

[wconrad]

ftpd currently supports Ruby versions going back to 1.9.3. __dir__ was introduced in 2.0, I think.

Can you tell me more about the symlink? Normally, if a gem is installed, its executables should automatically be in your path, so there'd be no need to create a symlink to it.

By the way, I found that ftpdrb wasn't running correctly at all when run from an installed gem. I fixed that in 9be1d37 and that fix is in 2.0.2 which I released today.