How to check if a directory/file/symlink exists with one command in Ruby

问题

Is there a single way of detecting if a directory/file/symlink/etc. entity (more generalized) exists?

I need a single function because I need to check an array of paths that could be directories, files or symlinks. I know File.exists?"file_path" works for directories and files but not for symlinks (which is File.symlink?"symlink_path").

回答1:

The standard File module has the usual file tests available:

RUBY_VERSION # => "1.9.2"
bashrc = ENV['HOME'] + '/.bashrc'
File.exist?(bashrc) # => true
File.file?(bashrc)  # => true
File.directory?(bashrc) # => false

You should be able to find what you want there.

---

OP: "Thanks but I need all three true or false"

Obviously not. Ok, try something like:

def file_dir_or_symlink_exists?(path_to_file)
  File.exist?(path_to_file) || File.symlink?(path_to_file)
end

file_dir_or_symlink_exists?(bashrc)                            # => true
file_dir_or_symlink_exists?('/Users')                          # => true
file_dir_or_symlink_exists?('/usr/bin/ruby')                   # => true
file_dir_or_symlink_exists?('some/bogus/path/to/a/black/hole') # => false

回答2:

Why not define your own function File.exists?(path) or File.symlink?(path) and use that?

来源：https://stackoverflow.com/questions/4897568/how-to-check-if-a-directory-file-symlink-exists-with-one-command-in-ruby