Module: Flydata::Util::FileUtil

Included in:
Helper::Action::ActionPosition, Helper::Action::SendLogs
Defined in:
lib/flydata/util/file_util.rb

Instance Method Summary collapse

Instance Method Details

#read_line(file_path, default_value = nil) ⇒ Object 



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# File 'lib/flydata/util/file_util.rb', line 11

def read_line(file_path, default_value = nil)
  ret = nil
  if FileTest.exist?(file_path)
    ret = File.readlines(file_path).first.to_s.strip
  end
  ret
end

#tail(path, num_of_lines) ⇒ Object

snip from gist.github.com/shaiguitar/6d926587e98fc8a5e301



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# File 'lib/flydata/util/file_util.rb', line 20

def tail(path, num_of_lines)
  file = File.open(path, "r")
  buffer_s = 512
  line_count = 0
  file.seek(0, IO::SEEK_END)

  offset = file.pos # we start at the end

  while line_count <= num_of_lines && offset > 0
    to_read = if (offset - buffer_s) < 0
                offset
              else
                buffer_s
              end

    file.seek(offset-to_read)
    data = file.read(to_read)

    data.reverse.each_char do |c|
      if line_count > num_of_lines
        offset += 1
        break
      end
      offset -= 1
      if c == "\n"
        line_count += 1
      end
    end
  end

  file.seek(offset)
  data = file.read
end

#write_line(file_path, new_value) ⇒ Object 



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# File 'lib/flydata/util/file_util.rb', line 4

def write_line(file_path, new_value)
  File.delete(file_path) if FileTest.exist?(file_path)
  File.open(file_path, 'w') do |out|
    out.write new_value
  end
end