CODEWITHSUNDEEP
rubyfileio
Picachieu
Picachieu

Reputation: 3782

How to get file mode in ruby?

I'm new to ruby file IO. I have a function that takes a File parameter, and I need to make sure that the file is in read-only mode.

def myfunction(file)
    raise ArgumentError.new() unless file.kind_of?(File)

    #Assert that file is in read-only mode
end

Any help would be appreciated!

Upvotes: 1

Views: 714

Answers (3)

a_Borham
a_Borham

Reputation: 24

You can use file.readable?, which returns true or false.

Please check this link.

Upvotes: 0

Galaxy
Galaxy

Reputation: 1279

So all you need is 'make sure make sure that the file is in read-only mode', why not just set it as readonly with FileUtils.chmod.

Or if actually you just want to test if it is readonly, use File.writeable?

Upvotes: 2

Andrew Schwartz
Andrew Schwartz

Reputation: 4657

If you don't need to raise an error, you can use reopen, I think something like:

file = file.reopen(file.path, "r")

I can't find a way to otherwise verify that there isn't a write stream, but here's a bit of a hack that will work. Although I don't like exception throwing being used in the expected path, you could use close_write:

begin
  file.close_write
  # you could actually raise an exception here if you want
  # since getting here means the file was originally opened for writing
rescue IOError
  # This error will be raised if the file was not opened for
  # writing, so this is actually the path we want
end

Upvotes: 2

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