How to check if a given directory exists in Ruby
RubyDirectoryRuby Problem Overview
I am trying to write a script which automatically checks out or updates a Subversion URL based on whether a specified directory exists or not.
For some reason, my code isn't working and always returns true even if it's false:
def directory_exists?(directory)
return false if Dir[directory] == nil
true
end
What am I doing wrong?
Ruby Solutions
Solution 1 - Ruby
If it matters whether the file you're looking for is a directory and not just a file, you could use File.directory?
or Dir.exist?
. This will return true only if the file exists and is a directory.
As an aside, a more idiomatic way to write the method would be to take advantage of the fact that Ruby automatically returns the result of the last expression inside the method. Thus, you could write it like this:
def directory_exists?(directory)
File.directory?(directory)
end
Note that using a method is not necessary in the present case.
Solution 2 - Ruby
You can also use Dir::exist?
like so:
Dir.exist?('Directory Name')
>Returns true
if the 'Directory Name' is a directory, false
otherwise.1
Solution 3 - Ruby
All the other answers are correct, however, you might have problems if you're trying to check directory in a user's home directory. Make sure you expand the relative path before checking:
File.exists? '~/exists'
=> false
File.directory? '~/exists'
=> false
File.exists? File.expand_path('~/exists')
=> true
Solution 4 - Ruby
File.exist?("directory")
Dir[]
returns an array, so it will never be nil
. If you want to do it your way, you could do
Dir["directory"].empty?
which will return true
if it wasn't found.
Solution 5 - Ruby
You could use Kernel#test
:
test ?d, 'some directory'
it gets it's origins from https://ss64.com/bash/test.html
you will notice bash test
has this flag -d
to test if a directory exists
-d file True if file is a Directory. [[ -d demofile ]]