How do I remove a setting from a YAML file?

Ruby
1

I’m working on a small command line app project at the moment and I need
to store settings. I decided to use YAML for the first time and a hash,
which is converted into a string which is in YAML, and then save that
into a file. The below is the code for the writing to the file:

read
previous_settings = @result
@settings.each do |k, v|
previous_settings[k] = v
end
if File.writable_real?(FILE)
File.open(FILE, ‘w+’) do |f|
f << previous_settings.to_yaml
end
@result = true
else
@result = false
end

All it does is it reads the file and sets its contents to the @result
variable. Then the previous_setting variable is set to that and the
contents of the @settings are added onto it. I then simply write to the
file. My question is: how do I delete a setting in a YAML file? Say this
is my YAML file:

foundation: http://foundation.zurb.com/files/foundation-4.1.6.zip
normalize: http://necolas.github.io/normalize.css/2.1.1/normalize.css
h5bp: https://github.com/h5bp/html5-boilerplate/archive/master.zip

And I want to remove the h5bp option? Is there a way of doing that
without actually opening the file, searching through it with Regex, and
then removing the setting and its value? I’m using Ruby 2.0.0p0
(2013-02-24 revision 39474) [x86_64-linux].

Thank so much!

2

Am Sun, 12 May 2013 20:39:37 +0900
schrieb “Rafal C.” [email protected]:

Hi Rafal,

File.open(FILE, ‘w+’) do |f|
f << previous_settings.to_yaml
end

Why do you use “w+” as the file mode? You don’t read from the file in
the supplied block.

My question is: how do I delete a setting in a YAML file?
Say this is my YAML file:

foundation: http://foundation.zurb.com/files/foundation-4.1.6.zip
normalize: http://necolas.github.io/normalize.css/2.1.1/normalize.css
h5bp: https://github.com/h5bp/html5-boilerplate/archive/master.zip

And I want to remove the h5bp option?

Simply load the YAML file, delete the corresponding hash key, and write
the file back out to disk.

hsh = YAML.load_file("yourfile.yml")
hsh.delete("h5bp")
File.open("yourfile.yml", "w"){|f| YAML.dump(hsh, f)}

Vale,
Marvin

–
Blog: http://pegasus-alpha.eu/blog

ASCII-Ribbon-Kampagne () | ASCII Ribbon Campaign ()

3

On Sun, May 12, 2013 at 8:36 AM, Rafal C. [email protected] wrote:

Works great, thanks a lot.

–
Posted via http://www.ruby-forum.com/.

Um, you do know that YAML files are plain, old text files and can be
edited by any text editor, yes?

4

Works great, thanks a lot.

5

Um, you do know that YAML files are plain, old text files and can be edited by
any text editor, yes?

Yeah, why are you asking?

6

On Sun, May 12, 2013 at 3:34 PM, Rafal C. [email protected] wrote:

Yeah, why are you asking?

Because you were asking how to remove a line from a YAML file…

7

tamouse mailing lists wrote in post #1108699:

On Sun, May 12, 2013 at 3:34 PM, Rafal C. [email protected] wrote:

Yeah, why are you asking?

Because you were asking how to remove a line from a YAML file…

In Ruby, not by hand.