ruby-on-rails – .seek在ruby中的含义

input_file = ARGV[0]

def print_all(f)
    puts f.read()
end

def rewind(f)
    f.seek(0)
end

def print_a_line(line_count,f)
puts "#{line_count} #{f.readline()}"
end

current_file = File.open(input_filE)

puts "First Let's print the whole file:"
puts # a blank line

print_all(current_filE)

puts "Now Let's rewind,kind of like a tape"

rewind(current_filE)

puts "Let's print the first line:"

current_line = 1
print_a_line(current_line,current_filE)