How do I write to a local file?

Question

I'm learning Ruby, and can't figure out how to open and write to a local file. How can I open a file and write a string to it?

It would be really good if you spent time reading through [the core and standard Ruby libraries](http://www.ruby-doc.org/) to familiarize yourself with what's available. Even if you don't know what everything is used for, over time you'll run into the need, and, having glanced at the documentation a few times, you'll remember it's in there somewhere. As is, your question is very elementary, and very well explained by the [IO classes' documentation](http://www.ruby-doc.org/core-2.0.0/IO.html). — the Tin Man, Oct 16 '13 at 04:26

Chris Cashwell · Answer 1 · 2013-10-15T22:17:32.613

1

Opening and writing to a file is done via Ruby's File class. Here's an example.

File.open('path/to/file.txt', 'w') do |file|
  file.write('this is how you write to a file')
end

The first argument to File#open is the relative file location. The second is the mode.

edited Oct 15 '13 at 22:17

answered Oct 15 '13 at 22:10

Chris Cashwell

Don't forget to close the file, `file.close`, after you're done writing to it. – HM1 Oct 15 '13 at 22:27
2

@HM1 the file will be automatically closed if a block is given. – Stefan Oct 15 '13 at 22:32
1

Don't forget to close the question – boulder_ruby Oct 16 '13 at 05:36

score 0 · Answer 2 · answered Oct 15 '13 at 23:31

0

To read from file

File.read(file)

To write string to file

File.write(file, string)

answered Oct 15 '13 at 23:31

sawa

1

@DavidLjungMadison, you probably should read the [IO class documentation](http://www.ruby-doc.org/core-2.0.0/IO.html) a bit more closely. @sawa's answer is correct as File inherits from IO, which has both class and instance versions of `read` and `write`. – the Tin Man Oct 16 '13 at 04:31
@DavidLjungMadison Don't tell a lie. It was not added in Ruby 2.0. It is available at least in Ruby 1.9.3. Don't make an un-useful excuse. – sawa Oct 17 '13 at 06:33
@DavidLjungMadison Doesn't it even come to your mind to remove your first comment that is telling false information? Really surprising. All you think of is thinking what another layer of excuse to add? – sawa Oct 18 '13 at 09:47

score -1 · Answer 3 · edited Oct 16 '13 at 04:34

-1

What exactly do you want? Do you want to download the photo and save it? Or do you want to save the URL of the photo?

You can save the photo with Mechanize, because Mechanize.new.get creates a new file retrieved from the given URL and response body.

file = Mechanize.new.get(url)
file.class #=> Is a file, returns Mechanize::File
file.save('photo.jpg')

You can name the file however you like, with the #save method.

Or you can save the URL of the photo in a file by using the Ruby File class.

File.open('photo_url.txt', 'w') { |file| file.write(url) }

The file will be automatically closed by Ruby after the block terminates.

edited Oct 16 '13 at 04:34

the Tin Man

answered Oct 15 '13 at 22:27

JanDintel

There's nothing in the question hinting that the OP wants to retrieve an image from a URL. – the Tin Man Oct 16 '13 at 04:34
There was, until it was edited – JanDintel Oct 16 '13 at 22:36

score -1 · Answer 4 · edited Oct 16 '13 at 05:56

-1

one liner

File.open(path, "w") {|f| f.write(string)}

edited Oct 16 '13 at 05:56

SheetJS

answered Oct 16 '13 at 05:39

boulder_ruby

yeah you're right doing it this way is stupid – boulder_ruby Oct 17 '13 at 23:39

4 Answers4