Ubuntu 15.10 and Rails (unable to install nodejs)

The guide I'm following gives this command as one of the steps to install Rails...

sudo add-apt-repository ppa:chris-lea/node.js

When typing that out in version 15.10, I got an error.

I read two forum posts suggesting to use 14.04 because 15.10 wasn't supported.

Rails install on XUbuntu 14.04 (ERROR: Failed to build gem native extension)

I am following the steps on this page verbatim but came across an error when I got to the point of installing Rails.  This is the error I got...

Fetching: nokogiri-1.6.7.1.gem (100%)
Building native extensions.  This could take a while...
ERROR:  Error installing rails:
 ERROR: Failed to build gem native extension.

    /home/user/.rvm/rubies/ruby-2.2.4/bin/ruby -r ./siteconf20151223-26597-j3i7to.rb extconf.rb
checking if the C compiler accepts ... *** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of necessary
libraries and/or headers.  Check the mkmf.log file for more details.  You may
need configuration options.

Provided configuration options:
 --with-opt-dir
 --without-opt-dir
 --with-opt-include
 --without-opt-include=${opt-dir}/include
 --with-opt-lib
 --without-opt-lib=${opt-dir}/lib
 --with-make-prog
 --without-make-prog
 --srcdir=.
 --curdir
 --ruby=/home/user/.rvm/rubies/ruby-2.2.4/bin/$(RUBY_BASE_NAME)
 --help
 --clean
/home/user/.rvm/rubies/ruby-2.2.4/lib/ruby/2.2.0/mkmf.rb:456:in `try_do': The compiler failed to generate an executable file. (RuntimeError)
You have to install development tools first.
 from /home/user/.rvm/rubies/ruby-2.2.4/lib/ruby/2.2.0/mkmf.rb:571:in `block in try_compile'
 from /home/user/.rvm/rubies/ruby-2.2.4/lib/ruby/2.2.0/mkmf.rb:522:in `with_werror'
 from /home/user/.rvm/rubies/ruby-2.2.4/lib/ruby/2.2.0/mkmf.rb:571:in `try_compile'
 from extconf.rb:80:in `nokogiri_try_compile'
 from extconf.rb:87:in `block in add_cflags'
 from /home/user/.rvm/rubies/ruby-2.2.4/lib/ruby/2.2.0/mkmf.rb:619:in `with_cflags'
 from extconf.rb:86:in `add_cflags'
 from extconf.rb:336:in `<main>'

extconf failed, exit code 1

Gem files will remain installed in /home/user/.rvm/gems/ruby-2.2.4/gems/nokogiri-1.6.7.1 for inspection.
Results logged to /home/user/.rvm/gems/ruby-2.2.4/extensions/x86_64-linux/2.2.0/nokogiri-1.6.7.1/gem_make.out

I read many forum posts where I tried a handful of suggestions and none of them worked. I finally came across a stack overflow post where the suggestion of running this command was towards the bottom...

sudo apt-get install libgmp-dev

...or...

sudo apt-get install libgmp3-dev

Many of the suggestions I found on a few different forum posts stated that I needed to run...

sudo apt-get install git-core curl zlib1g-dev build-essential libssl-dev libreadline-dev libyaml-dev libsqlite3-dev sqlite3 libxml2-dev libxslt1-dev libcurl4-openssl-dev python-software-properties libffi-dev

...but given the setup guide I'm following (along with a few notes I've take), I'd already installed all of those packages.  The extra package needs to be installed for XUbuntu 14.04 and the regular Ubuntu 14.04 images in order to install Rails.

Installing Ruby onto XUbuntu 14.04 (kept installing source)

Trying to install ROR on an XUbuntu 14.04 VirtualBox vm.  Thought I'd mention one of the problems I ran into.  At first I was trying to install RVM/ROR etc from this page on an xubuntu-14.04.3-desktop-i386 image and every time I got to the part of running this line...

rvm install 2.2.3

...the install would download the source and then have to compile.  After some troubleshooting and reading some forum posts, I found out that the binaries weren't available. I did that by typing...

rvm list remote

...and only 2 JRuby binaries were showing up.  When I typed in...

rvm info

...I then noticed I was in a 32 bit environment and not a 64 bit environment like my other Ubuntu image.  After downloading and installing the 64 bit image (xubuntu-14.04.3-desktop-amd64.iso), I no longer had this issue.

My RoR install

I've discovered and decided to follow through with the free online tutorial/class on the Odin Projects website.  Because I'm trying to become a full stack Ruby developer, I figured it would be good material to read and try to absorb.

I'm currently on the Web Development 101 >> The Basics >> Project Installations section where it's instructing all those following along to decide on an environment.  Yes, I did go ahead and sign up for a free account on the Nitrous website just to check it out. If you click the link on the Odin Project website that takes you to the Nitrous website, you do get a free account.  Going directly to the Nitrous website won't allow you to setup a free account.

Even though I setup an account on Nitrous, if I am going to want to plant myself into a development position, I need to get as familiar with the Linux platform as best as I can so I'm following along with the Linux environment setup. The Odin Project points it's followers to the RailsBridge Installfest webpage to setup an environment. If you get errors setting up your environment, they strongly encourage you to go through Nitrous.

I went ahead and followed the directions found on RailsBridge but ran into an error trying to install RVM. They also don't mention anything about modifying your bashrc file. In the past, I've also followed the setup instructions on the GoRails website. I'm going to list below the steps I took to get my environment setup but will give the readers digest version. If you want more of an explanation on these steps, please click on the appropriate link above.


I use Windows because that is what I'm most familiar as well as that is the platform that we must use where I work. So I use virtual machines with Linux installed.  My current choice of Linux flavor is Ubuntu. I created a brand new machine with version 14.04. I installed SPE (for when I do get back to learning Python).  I was using Scite but then I tried Geany out one day and fell in love with it because of the option to have a terminal window within one program and I don't have to switch back and forth when I want to try something out in IRB.  To each their own on which editor you choose.

From the point of having Ubuntu installed and updated along with having an editor ready to go, I performed the following steps in the terminal...

sudo apt-get install autoconf automake bison build-essential curl git-core 
libapr1 libaprutil1 libc6-dev libltdl-dev libreadline6 libreadline6-dev 
libsqlite3-0 libsqlite3-dev libssl-dev libtool libxml2-dev libxslt-dev 
libxslt1-dev libyaml-dev ncurses-dev nodejs openssl sqlite3 zlib1g
zlib1g-dev
 

Note: Do not copy and paste the above into your terminal window. Type it all out. 

If you are running Ubuntu 12.04 or 14.04, click on the Edit option on your terminal window, choose the Profile Preferences option, select the Title and Command tab and finally make sure there is a check mark next to the Run command as a login shell box. Click on the close button and then restart your terminal session.

Now to install RVM (assuming you don't want to use rbenv).  Instructions I've read from a few websites state to run this line...

curl -L get.rvm.io | bash -s stable

...I get a "GPG signature verification failed..." message when I try and download rvm.  A few lines below that error message it tells me to run...

gpg --keyserver hkp://keys.gnupg.net --recv-keys 409B6B1796C275462A1703113804BB82D39DC0E3

If that fails, you can run the following...

command curl -sSL https://rvm.io/mpapis.asc | gpg --import -

The line on your screen may be different. After obtaining the key, I'm now able to run the curl line above.

When I try and run...

type rvm | head -1

...I get "-bash: type: rvm: not found".  When I close the terminal again and restart it and run the above command, I get...

rvm is a function

...which is a good thing. Next, enter the following two lines to update your environment and to make the appropriate change to your bashrc profile...

source ~/.rvm/scripts/rvm
echo "source ~/.rvm/scripts/rvm" >> ~/.bashrc


Next install RVM with the following...

rvm install 2.2

This process took 5 minutes on my machine. On the last line you see after the above process completes is "Ruby was built without documentation, to build it run: rvm docs generate-ri".  I personally like to have my documentation local so I went ahead and ran...

rvm docs generate-ri

This process took 1-2 minutes. Next, type in the following two commands...

rvm use 2.2
rvm --default use 2.2

To test your installation, type the following...

ruby -v

Last but not least, install rails with the following...

gem install rails

That's all I will cover for this entry. I'm still new to all of this but I've read a lot of blogs and documentation on the install. If I've messed something up, by all means, please comment.

Try googling 'Ruby question mark'...without the quotes

I've been following the exercises on RubyMonk and at least 2 exercises so far use a question mark.  This symbol is not at the end of empty? or include? etc.  It's not even being used in a regex.  When I can't figure something out, I get frustrated. I've given up on a few of these exercises and had to hit the option "See the solution".  It was even more frustrating when the solution uses syntax not introduced in the lesson or even hinted at on the page asking you to solving a problem.  RubyMonk is not the only site that has this problem.  Had to vent...sorry.

Some Ruby beginners but most intermediate and all advanced will know that what I speak of above is the ternary or conditional operator. I have been googling Ruby question mark and adding words like symbol and comparison.  Right now, I'm working on the problem named Number Shuffle.  I had to click on the "See the solution" option which is the second time I'm seeing a question mark.  Here's the specific line...

no_of_combinations = number.to_s.size == 3 ? 6 : 24

Searching for this kept sending me to pages that discussed array/string elements ending with a question mark or pages discussing regular expressions. I finally found a page that talks about [value] ? [value] : [value]  I guess I wasn't using the right search terms or something.

I found the explanation on this page...

http://ruby.about.com/od/beginningruby/a/The-Ternary-Or-Conditional-Operator.htm

Here is the text that set me straight and answered my question...

The general format of this expression is as follows: conditional ? true : false. If the conditional expression is true, then the operator will evaluate as the true expression, otherwise it will evaluate as the false expression.

Now that I found out that this is a ternary operator, I can google and find all kinds of explanations on it. It would be nice if online tutorials explained or gave references to all syntax used.

Learning Regex con't (xxxxxxx-xxxx where x's are digits)

This one (regex) didn't take me as long to figure out given all that I read about regular expressions.

As part of my homework for Learning Ruby the Hard Way, I'm still working on my editor that takes 8 pieces of information and inserts it all into a tab delimited format .txt file.  The second column needs to be in the format of xxxxxxx-xxxx where the x's are digits and the hyphen needs to be included.  This is an account id in the system I'm working with where I'm going to eventually create a script to combine rows from files a 3rd party agency is giving to us.

Back to the editor, I created a regex to only accept an account id that has 7 digits, a hyphen followed by 4 more digits.  This one was easy compared to the online tutorials I was reading over.  Just inserting the regex here so I'll have it for future reference.

/^\d{7}\-\d{4}$/

Maybe by the time I'm finished with the 2 projects I want to complete, I'll have a cook book of regex's.

Learning Regex (file name with .txt extension)

I've gone through 6-7 web pages and 2 tutorials.  I did an initial search for a regex for a file name.  I didn't search but a minute or two then decided I need to learn a little more about regular expressions than just how to come up with one to recognize a file name.

After reading through a lot of documentation, I believe I came up with what I needed but first a little background.

I'm on lesson 36 of Learn Ruby the Hard Way.  I'm not making a game like the home suggests to.  Instead, I'm making a script that will ask for eight pieces of information and it will create a tab delimited file with each piece of information.  I'm giving the user the option to name the file.  The requirements will be that it must only contain letters (upper/lower case), digits, a hyphen and an underscore character and the file extension must end with a ".txt" (without the double quotes).  If the user types in anything else, it won't be accepted.

So I'm still at the beginning of creating this script and had to stop for a few days to learn how to put together regular expressions.  This is what I have so far for an acceptable file name.

I chose this type of project over creating a game because I need to ultimately create a script that parses a tab delimited file and combines rows/records based on values in 2 columns.  That will be my next project.

Here's the regex that I came up with to accept a file name with the above mentioned requirements.

/^[^\W+]\w+\-?(.txt$)/

I'm always open for suggestions on simplifying my code. I'm in no way an expert but the above expression works for what I need it for.  I'll be studying regular expressions in more depth as I continue on with my projects.