Problem
You would like to refresh your local git repository after deleting some remote branches, usually after merging them to a develop,master etc repository, so doing branch -a or branch -r would not display them anymore.
Solution
You would need to issue the following git command:
git remote prune origin
And then doing a branch -r or branch -a should not display the deleted remote branches anymore.
Problem
You want to search in a directory or some files for a specific string and you also want to know the number in the file that the text is found.
Solution
Use grep with the -n for the line number and the -r for directory search as in the following:
grep -n -r 'search_item' /path/to/folder/
Problem
After installing rvm on dreamhost, when trying to install any ruby version afterwards, there is a prompt for password, and when entering the user’s password there is the message that the user is not in the sudoers list.
Solution
To be able to install the rvm ruby version you would like you should be installing them by using the following which is based on the answer here :
rvm list remote ruby-1.9.3-p194 ruby-1.9.3-p286 ruby-1.9.3-p327 ruby-1.9.3-p362 ruby-1.9.3-p374 ruby-1.9.3-p392 ruby-1.9.3-p429 ruby-1.9.3-p448 ruby-2.0.0-p0 ruby-2.0.0-p195 ruby-2.0.0-p247
and then:
rvm mount -r https://rvm.io/binaries/debian/6/x86_64/ruby-2.0.0-p247.tar.bz2 --verify-downloads 1
Problem
When trying to use the new Capistrano 3.x to set up your rails project in a dreamhost account, you get the following error complaining that the git-ssh.sh script copied to your account by capistrano cannot be executed as the permission is denied:
fatal: cannot exec '/tmp/example.com/git-ssh.sh': Permission denied
Solution
It seems that Dreamhost, and quite possibly other hosting providers are not allowing executables from the /tmp directory, which is where Capistrano places the git-ssh.sh script. So in order to be able to execute the script you can change the directory where the script is copied in the first place and put it in your home directory. You can do that by adding the following to the config/deploy.rb file:
set :tmp_dir, "/home/dh_user_name/tmp"
Problem
In your rails project very often, after creating a new migration, you have to run the migration in the development database and then in the test database.
Solution
A neat way to combine both these steps as one, taken from the book Rails 4 in Action, is to create an alias in your ~/.bashrc configuration file with the following, so that you only have to run migrate after each migration that would apply the migration in both development and test databases:
alias migrate='bin/rake db:migrate && bin/rake db:test:prepare'
Problem
You have forgotten your web-gui credentials to login into your dd-wrt router but you have still telnet access to it.
Solution
Login with telnet to your router and then run the following two commands to reset the web interface:
nvram set http_passwd= nvram commit
and then go to your Web interface to set a new one.
* Based on this post
Very nice infographic explaining the origin of some common UI symbols:
Exploring Everyday Things with R and Ruby, as the title suggests, is a book about data exploration, written in a very easy and very unusual way, that will make it hard to put down.
In the beginining it starts with a short introduction to the two languages used to achieve its purpose.
It gives a short explanation about the reason of using Ruby, followed by installation instructions and some basic ruby information. After that there is a short introduction to Ruby’s UI toolkit called Shoes.
The second initial part covers the other language to be used in the examples to follow, R. There are again the reason for picking R, installation instructions and a brief introduction to the capabilities of the language and especially the data analysis and graphing abilities.
Following the first two parts, is where the book starts to get really interesting and fun and it will certainly make you want to try the examples worked on.
Subjects like ‘Offices and Restrooms’ which is about deternining the correct people-to-restrooms ratio, ‘How to Be an Armchair Economist’ about a market economy simulation, ‘Discover Yourself Through Email’ dealing with email data mining, ‘In A Heartbeat’ for measuring the hearbeat, including a homemade digital stethoscope, ‘Schooling Fish and Flocking Birds’ a simulation of the Boids algorithm in Ruby, and finally ‘Money, Sex and Evolution’ an entire artificial world populate by the roids of the previous example.
All of the examples are fascinating, something that I would never imagine it would be possible to simulate before reading this book, and also include information about their specific fields.
So in conclusion, it is a very enjoyable, interesting and out of the ordinary book, helped greatly by the author’s unique writing style, and one that I would recommend to anyone with an interest in Ruby or R to read.
Problem
You would like to use the build method for creating an association (details) that belongs to another assocation (user).
When the user has many details then you would have something like the following:
class User < ActiveRecord::Base has_many :details end
then you could do:
User.details.build
but when you have:
class User < ActiveRecord::Base has_one :detail end
would throw an error:
NoMethodError: undefined method `build' ...
Solution
In order to be able to use the build in a has_one relation you would need to use like:
User.build_detail
Problem
You are getting a libv8 installation error in a new rails 4.0 application in an older linux installation
An error occurred while installing libv8 (3.16.14.3), and Bundler cannot continue. Make sure that `gem install libv8 -v '3.16.14.3'` succeeds before bundling.
Solution
This is causes by the latest gem version of the therubyracer dependency on the libv8.
You can get over it by specifying version 0.11.4 for the gem as in:
gem 'therubyracer', '~> 0.11.4', platforms: :ruby
and then running bundle install again.