Merge pull request #1854 from github/more-shebang-fixes

More shebang fixes

lib/linguist/shebang.rb

@@ -18,23 +18,32 @@ module Linguist
     #
     # Returns a String or nil
     def self.interpreter(data)
-      lines = data.lines
-      return unless match = /^#! ?(.+)$/.match(lines.first)
+      shebang = data.lines.first
 
-      tokens = match[1].split(' ')
-      script = tokens.first.split('/').last
+      # First line must start with #!
+      return unless shebang && shebang.start_with?("#!")
 
+      # Get the parts of the shebang without the #!
+      tokens = shebang.sub(/^#!\s*/, '').strip.split(' ')
+
+      # There was nothing after the #!
+      return if tokens.empty?
+
+      # Get the name of the interpreter
+      script = File.basename(tokens.first)
+
+      # Get next argument if interpreter was /usr/bin/env
       script = tokens[1] if script == 'env'
 
-      # If script has an invalid shebang, we might get here
+      # Interpreter was /usr/bin/env with no arguments
       return unless script
 
       # "python2.6" -> "python2"
-      script.sub! $1, '' if script =~ /(\.\d+)$/
+      script.sub! /(\.\d+)$/, ''
 
       # Check for multiline shebang hacks that call `exec`
       if script == 'sh' &&
-        lines.first(5).any? { |l| l.match(/exec (\w+).+\$0.+\$@/) }
+        data.lines.first(5).any? { |l| l.match(/exec (\w+).+\$0.+\$@/) }
         script = $1
       end
 

test/test_shebang.rb

@@ -17,6 +17,8 @@ class TestShebang < Test::Unit::TestCase
     assert_interpreter nil, " #!/usr/sbin/ruby"
     assert_interpreter nil, "\n#!/usr/sbin/ruby"
     assert_interpreter nil, "#!"
+    assert_interpreter nil, "#! "
+    assert_interpreter nil, "#!/usr/bin/env"
 
     assert_interpreter "ruby", "#!/usr/sbin/ruby\n# bar"
     assert_interpreter "ruby", "#!/usr/bin/ruby\n# foo"
@@ -34,6 +36,8 @@ class TestShebang < Test::Unit::TestCase
     assert_interpreter "python3", "#!/usr/bin/python3\n\n\n\n"
     assert_interpreter "sbcl", "#!/usr/bin/sbcl --script\n\n"
     assert_interpreter "perl", "#! perl"
+
+    assert_interpreter "ruby", "#!/bin/sh\n\n\nexec ruby $0 $@"
   end
 
 end