最近在做下載html頁面的時候，用了rubyzip包，它的說明文檔裏有這樣一段可以直接拿來用的

require ‘zip‘
# This is a simple example which uses rubyzip to
# recursively generate a zip file from the contents of
# a specified directory. The directory itself is not
# included in the archive, rather just its contents.
#
# Usage:
#   directory_to_zip = "/tmp/input"
 

#   output_file = "/tmp/out.zip"
#   zf = ZipFileGenerator.new(directory_to_zip, output_file)
#   zf.write()
class ZipFileGenerator
  # Initialize with the directory to zip and the location of the output archive.
  def initialize(input_dir, output_file)
    @input_dir = input_dir
    @output_file = output_file
  end

  
 
# Zip the input directory.
  def write
    entries = Dir.entries(@input_dir) - %w(. ..)

    ::Zip::File.open(@output_file, ::Zip::File::CREATE) do |zipfile|
      write_entries entries, ‘‘, zipfile
    end
  end

  private

  # A helper method to make the recursion work.
  def write_entries(entries, path, zipfile)
    entries.each do 
 
|e|
      zipfile_path = path == ‘‘ ? e : File.join(path, e)
      disk_file_path = File.join(@input_dir, zipfile_path)
      puts "Deflating #{disk_file_path}"

      if File.directory? disk_file_path
        recursively_deflate_directory(disk_file_path, zipfile, zipfile_path)
      else
        put_into_archive(disk_file_path, zipfile, zipfile_path)
      end
    end
  end

  def recursively_deflate_directory(disk_file_path, zipfile, zipfile_path)
    zipfile.mkdir zipfile_path
    subdir = Dir.entries(disk_file_path) - %w(. ..)
    write_entries subdir, zipfile_path, zipfile
  end

  def put_into_archive(disk_file_path, zipfile, zipfile_path)
    zipfile.get_output_stream(zipfile_path) do |f|
      f.write(File.open(disk_file_path, ‘rb‘).read)
    end
  end
end

於是按照說明直接使用，我的代碼如下：

report_path = "path/folder" # 某個path下的folder
output_file = Rails.root.join(download_path, "report.zip")
File.delete(output_file) if File.exists?(output_file)
zf = ZipFileGenerator.new(report_path, output_file)
zf.write()

這時出現了Errno::EACCES (Permission denied @ rb_sysopen的錯誤。

它的意思應該是沒有權限打開文件。

按照這個思路分析，去排查權限的問題，但權限都是正常的，沒有什麽問題。

再去看說明文檔，發現了其中的原由，文檔裏有這麽一段：

# Usage:
#   directory_to_zip = "/tmp/input"
#   output_file = "/tmp/out.zip"
#   zf = ZipFileGenerator.new(directory_to_zip, output_file)
#   zf.write()

這說明directory_to_zip和output_file都是string對象。

而我傳入的Rails.root.join(download_path, "report.zip")，是一個Pathname對象，這導致了錯誤的出現。

我們平常在rails裏較為常用的Rails.root.join和File.join的區別就是返回的對象不同，並且Rails.root使用時也可以像字符一樣，以致我都認為它就是返回的字符串，所以才導致了這樣的錯誤，以後還是要仔細些才行，不要再犯同樣的錯誤，特此mark一下。

rubyzip 壓縮文件夾時遇到Errno::EACCES (Permission denied @ rb_sysopen -