Errno::ENOENT: 没有那个文件或目录 ruby [英] Errno::ENOENT: No such file or directory ruby

问题描述

我收到以下错误:

"Errno::ENOENT: No such file or directory"

当我尝试将文件下载到不存在的目录时.

when I try to download a file into a directory that does not exist.

例如:

ftp = Net::FTP.new('example.com')
ftp.login
files = ftp.chdir('pub/lang/ruby/contrib')
files = ftp.list('n*')
ftp.getbinaryfile('nif.rb-0.91.gz', 'pub/lang/ruby/contrib/nif.gz', 1024)
ftp.close

但是，对于我将要下载的许多文件，完整的目录路径将不存在.例如，在第一个文件创建 pub 之前，它不会存在，这也适用于 lang/ruby/contrib.

However, for many of the files I will be downloading, the full directory path will not exist. For example, until the first file creates pub, it won't exist and this goes for lang/ruby/contrib too.

有没有一种方法可以检查目录是否存在，如果不存在则创建它们?我知道存在吗?，但这看起来是参考文件，它不会创建完整路径.我想我需要一些递归方法来遍历文件夹结构，直到遇到文件名.

Is there a method that can check if directories exist and if not create them? I know that there is exist?, but that looks to reference files and it does not create the full path. I figure I need some recursive method to traverse down the folder structure until it hits the filename.

mkdir_p 似乎正是我需要的解决方案.

mkdir_p seems to be exactly the solution I need.

但是，当我使用/a/b/c"路径时，我注意到FileUtils.mkdir_p(File.dirname(localdir))返回错误:Errno::EACCES: Permission denied -/a

However, when I use a path of "/a/b/c" I noticed that FileUtils.mkdir_p(File.dirname(localdir)) returns an error: Errno::EACCES: Permission denied - /a

如果我手动删除前面的/"，它会起作用.这是什么原因造成的?解决错误的最佳解决方案是什么?我应该只使用以下内容吗?

If I remove the "/" in front manually it works. What is causing this? What is the best solution for resolving the error? should I just use the following?

 path="/a/b/c"
 if path[0]="/"
    path=path[1..-1]
 end

然而，我觉得这只是一个黑客.

However, I feel like this is just a hack.

推荐答案

您无法保存到不存在的路径.作为开发人员，您有责任在尝试保存文件之前确保目标路径存在.

You can't save to a non-existing path. As the developer you're responsible to make sure your destination paths exist prior to trying to save the file.

Ruby 有一些方法可以让您检查文件或目录是否存在:

Ruby has methods that let you check for the existence a file or directory:

• File.exist?('path/to/file')
• File.file?('path/to/file')
• File.directory?('path/to/file')
• Dir.directory?('path/to/dir')
• Dir.mkdir('path/to/dir')
• FileUtils.makedirs('path/to/目录')

FileUtils.makedirs() 是 mkpath 和 mkdir_p 的别名.我更喜欢 makedirs 因为它是一个助记符.

FileUtils.makedirs() is an alias to mkpath, and mkdir_p. I prefer makedirs because it's a mnemonic.

这些也很有用:

• Dir.chdir('path/to/dir')
• FileUtils.chdir('path/to/dir')

在这两者之间我更喜欢 Dir.chdir，因为它需要一个块.该块内发生的任何操作都发生在您更改的目录中.退出时，目录恢复到以前的状态.

Between those two I prefer Dir.chdir, because it takes a block. Any actions that occur inside that block happen in the directory you changed to. At exit, the directory reverts to what it was previously.

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