insert_header.rb

#!/usr/bin/env ruby

# Copyright (C) 2015 Centro de Computacao Cientifica e Software Livre
# Departamento de Informatica - Universidade Federal do Parana
#
# This file is part of portalmec.
#
# portalmec is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# portalmec is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with portalmec.  If not, see <http://www.gnu.org/licenses/>.


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])
}