rubyzip 压缩文件夹时遇到Errno::EACCES (Permission denied @ rb_sysopen -

最近在做下载html页面的时候，用了rubyzip包，它的说明文档里有这样一段可以直接拿来用的

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

于是按照说明直接使用，我的代码如下：

report_path = "path/folder" # 某个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()

这时出现了Errno::EACCES (Permission denied @ rb_sysopen的错误。

它的意思应该是没有权限打开文件。

按照这个思路分析，去排查权限的问题，但权限都是正常的，没有什么问题。

再去看说明文档，发现了其中的原由，文档里有这么一段：

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

这说明directory_to_zip和output_file都是string对象。

而我传入的Rails.root.join(download_path, "report.zip")，是一个Pathname对象，这导致了错误的出现。

我们平常在rails里较为常用的Rails.root.join和File.join的区别就是返回的对象不同，并且Rails.root使用时也可以像字符一样，以致我都认为它就是返回的字符串，所以才导致了这样的错误，以后还是要仔细些才行，不要再犯同样的错误，特此mark一下。

原文地址：https://www.cnblogs.com/limx/p/9059896.html