Added script to add header to files, maintaining shebangs

insert_header.rb

+#!/usr/bin/env ruby
+
+require 'fileutils'
+
+# array of tuples
+HEADER_FILENAME = 0
+EXTENSIONS = 1
+headers = [
+	# file with license commented with hashtags # like this
+	# codes with hashtag comments
+	["license.txt", [".rb", ".yml", ".rake", ".ru", ".sh"]]
+	# add other files that use other comment types
+	# add other extensions that use other comment types
+]
+
+# if your code commets aren't hashtags, create other license files
+# add new license file and file extensions to the array like this
+
+# headers = [
+# 	["license.slash.txt", [".ext_with_slash"]]
+# 	["license.hash.txt", [".ext_with_hash1", ".ext_with_hash2"]]
+# ]
+
+# inserts contents of file 'header_filename' into all files of type in the array 'extensions'
+def insert_header_on_filetypes(extensions, header_filename)
+	extensions.each { |e|
+		Dir.glob("#{Dir.pwd}/**/*#{e}").each { |filename|
+			new_f = File.join(File.dirname(filename), File.basename(header_filename) + ".tmp")
+
+			FileUtils.cp(header_filename, new_f)
+
+			puts "Appending " + filename + " into " + new_f
+			File.open(filename, "r") { |file|
+      		line = file.gets
+				# if file has shebang on first line
+				if line.start_with?("#!/")
+					File.open(new_f,"w") { |merged_file|
+						# adds the original file shebang #!/usr/bin/[..] as first line
+						merged_file << line
+
+						# writes header file
+						File.open(header_filename, "r") { |header_file|
+							while h_line = header_file.gets
+								merged_file << h_line
+							end
+						}
+
+						# writes remaining source file
+						while line = file.gets
+							merged_file << line
+						end
+					}
+				# if file doesn't have shebang on first line
+				else
+					File.open(new_f,"a") { |merged_file|
+						# appends source file to header_file
+						merged_file << line
+						while line = file.gets
+							merged_file << line
+						end
+					}
+				end
+			}
+
+			puts "Overwriting \"" + new_f + "\" into " + filename
+			File.rename(new_f, filename)
+			puts "done\n\n"
+		}
+	}
+end
+
+def checkFile(path)
+	if !File.file?(path)
+		puts "Header file specified #{File.basename(path)} does not exist on current directory, please create one"
+		exit
+	end
+end
+
+headers.each { |header|
+	checkFile(header[HEADER_FILENAME])
+	insert_header_on_filetypes(header[EXTENSIONS], header[HEADER_FILENAME])
+}