How to write to file in Ruby?

I need to read the data out of database and then save it in a text file.

How can I do that in Ruby? Is there any file management system in Ruby?

Are you looking for the following?

File.open(yourfile, 'w') { |file| file.write("your text") }

[Zambri][1]'s answer [found here][2] is the best.


File.open("out.txt", '<OPTION>') {|f| f.write("write your stuff here") }

where your options for `<OPTION>` are:

`r` - Read only. The file must exist.

`w` - Create an empty file for writing.

`a` - Append to a file.The file is created if it does not exist.


`r+` - Open a file for update both reading and writing. The file must exist.

`w+` - Create an empty file for both reading and writing.

`a+` - Open a file for reading and appending. The file is created if it does not exist.

In your case, `w` is preferable.


[1]:

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[2]:

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For those of us that learn by example...

Write text to a file like this:

IO.write('/tmp/msg.txt', 'hi')

BONUS INFO ...

Read it back like this

IO.read('/tmp/msg.txt')

Frequently, I want to read a file into my clipboard ***

Clipboard.copy IO.read('/tmp/msg.txt')

And other times, I want to write what's in my clipboard to a file ***

IO.write('/tmp/msg.txt', Clipboard.paste)

*** Assumes you have the clipboard gem installed

See:

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This is preferred approach in most cases:

File.open(yourfile, 'w') { |file| file.write("your text") }

When a block is passed to `File.open`, the File object will be automatically closed when the block terminates.

If you don't pass a block to `File.open`, you have to make sure that file is correctly closed and the content was written to file.

begin
file = File.open("/tmp/some_file", "w")
file.write("your text")
rescue IOError => e
#some error occur, dir not writable etc.
ensure
file.close unless file.nil?
end

You can find it in [documentation][1]:

static VALUE rb_io_s_open(int argc, VALUE *argv, VALUE klass)
{
VALUE io = rb_class_new_instance(argc, argv, klass);
if (rb_block_given_p()) {
return rb_ensure(rb_yield, io, io_close, io);
}
return io;
}

[1]:

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The Ruby [File class](

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) will give you the ins and outs of `::new` and `::open` but its parent, the [IO class](

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), gets into the depth of `#read` and `#write`.

To destroy the previous contents of the file, then write a new string to the file:

<!-- language: lang-rb -->

open('myfile.txt', 'w') { |f| f << "some text or data structures..." }

To append to a file without overwriting its old contents:

<!-- language: lang-rb -->

open('myfile.txt', "a") { |f| f << 'I am appended string' }

You can use the short version:

File.write('/path/to/file', 'Some glorious content')

It returns the length written; see [::write][1] for more details and options.

To append to the file, if it already exists, use:

File.write('/path/to/file', 'Some glorious content', mode: 'a')


[1]:

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