ex16.rb

filename = ARGV.first

puts "We're going to erase #{ filename }"
puts "If you don't want that, hit CTRL-C (^C)."
puts "If you do want that, hit RETURN."

$stdin.gets

puts "Opening the file..."
target = open(filename, 'w')
# w = create an empty file for editing, or erase if file of same name is present.

puts "Truncating the file. Goodbye!"
target.truncate(0)
# Technically don't need this stuff above, since the w 
# handles removing the file contents, or creating a clean file.

puts "Now I'm going to ask you for three lines."

print "line 1:  "
line1 = $stdin.gets.chomp
print "line 2:  "
line2 = $stdin.gets.chomp
print "line 3:  "
line3 = $stdin.gets.chomp

puts "I'm going to write these to the file."

target.write(line1 + "\n" + line2 + "\n" + line3 + "\n" )

puts "And finally, we close it."
target.close