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Some amazing IEEE magazines for good reads

ComputingEdge magazine by IEEE Computer Society

At the following link (https://www.computer.org/web/computingedge/current-issue) you will find all of the issues of the ComputingEdge magazine of IEEE.

This publication is produced by the Computer Society and we believe you will find it to be very interesting to read.

ComputingEdge curates the hot technology knowledge from the 13 leading technology publications of Computer Society, plus adds unique original content, and makes it available in a single experience. The features and columns in ComputingEdge always emphasize the newest developments and current trends. ComputingEdge keeps you up to date by showing you what’s hot and what you need to know across the technology spectrum. It’s both an informative and an enjoyable read. ComputingEdge caters to your need-to-know key information about all aspects of the technology arena so you can make integrated decisions regarding your areas of specialty.

Modified from: https://www.computer.org/web/computingedge/

We’ve been reading this magazine for some time now and there is always a couple of articles that get our attention.

 


Fedora 27: Setup stackskills-dl

A couple of days ago we were asked to setup stackskills-dl on a Fedora 27 (x64).
Apparently stackskills-dl is a Ruby script that allows a registered user to download the StackSkills tutorials for which the user has access to.

Following the instructions at https://github.com/yoonwaiyan/stackskills-dl are not enough to get the application running as the json gem and the Ruby development files appear to be missing from the filesystem.

Solution: Below are the steps we followed to setup stackskills-dl and make it operational:

sudo dnf install gem ruby-devel youtube-dl wget;
gem install json;
gem install bundler;
git clone https://github.com/yoonwaiyan/stackskills-dl.git;
cd stackskills-dl/;
bundle install;

After the above steps were completed, we were able to use stackskills-dl from the clone/installation folder normally:

[[email protected] stackskills-dl]$ ruby stackskills_dl.rb -u "[email protected]ample.com" -p "e#rf54HTw3se!fe678f." -s https://stackskills.com/courses/enrolled/007;
Loaded login credentials from environment variables.
Login Successfully.
Finding https://stackskills.com/courses/enrolled/007 from your list of courses
Number of courses found: 1
...

[[email protected] stackskills-dl]$ ruby stackskills_dl.rb --help
Usage: ruby stackskills_dl.rb [options]
-u, --email NAME Email
-p, --password PASSWORD Password
-c, --course COURSE_URL Course URL in ID.
-s, --course-slug COURSE_SLUG Course URL in slug.

With out the Ruby json gem you would get the following error:

[[email protected] stackskills-dl]$ ruby stackskills_dl.rb --help;
/usr/share/rubygems/rubygems/core_ext/kernel_require.rb:55:in `require': cannot load such file -- json (LoadError)
from /usr/share/rubygems/rubygems/core_ext/kernel_require.rb:55:in `require'
from /home/george/.gem/ruby/2.4.0/gems/mime-types-2.99.1/lib/mime/types/loader.rb:226:in `load_from_json'
from /home/george/.gem/ruby/2.4.0/gems/mime-types-2.99.1/lib/mime/types/loader.rb:63:in `block in load_json'
from /home/george/.gem/ruby/2.4.0/gems/mime-types-2.99.1/lib/mime/types/loader.rb:62:in `each'
from /home/george/.gem/ruby/2.4.0/gems/mime-types-2.99.1/lib/mime/types/loader.rb:62:in `load_json'
from /home/george/.gem/ruby/2.4.0/gems/mime-types-2.99.1/lib/mime/types/loader.rb:88:in `load'
from /home/george/.gem/ruby/2.4.0/gems/mime-types-2.99.1/lib/mime/types/loader.rb:113:in `load'
from /home/george/.gem/ruby/2.4.0/gems/mime-types-2.99.1/lib/mime/types.rb:296:in `load_default_mime_types'
from /home/george/.gem/ruby/2.4.0/gems/mime-types-2.99.1/lib/mime/types.rb:323:in `<class:Types>'
from /home/george/.gem/ruby/2.4.0/gems/mime-types-2.99.1/lib/mime/types.rb:63:in `<top (required)>'
from /usr/share/rubygems/rubygems/core_ext/kernel_require.rb:55:in `require'
from /usr/share/rubygems/rubygems/core_ext/kernel_require.rb:55:in `require'
from /home/george/.gem/ruby/2.4.0/gems/mechanize-2.7.4/lib/mechanize/pluggable_parsers.rb:5:in `<top (required)>'
from /usr/share/rubygems/rubygems/core_ext/kernel_require.rb:55:in `require'
from /usr/share/rubygems/rubygems/core_ext/kernel_require.rb:55:in `require'
from /home/george/.gem/ruby/2.4.0/gems/mechanize-2.7.4/lib/mechanize.rb:1361:in `<top (required)>'
from /usr/share/rubygems/rubygems/core_ext/kernel_require.rb:133:in `require'
from /usr/share/rubygems/rubygems/core_ext/kernel_require.rb:133:in `rescue in require'
from /usr/share/rubygems/rubygems/core_ext/kernel_require.rb:40:in `require'
from /home/george/Videos/stackskills-dl/lib/course_finder.rb:1:in `<top (required)>'
from /usr/share/rubygems/rubygems/core_ext/kernel_require.rb:55:in `require'
from /usr/share/rubygems/rubygems/core_ext/kernel_require.rb:55:in `require'
from stackskills_dl.rb:4:in `<main>'


Automatically download possibly a whole public website using wget recursively

The following command will try to download a full website with all pages it can find through public links.

wget --wait=2 --limit-rate=200K --recursive --no-clobber --page-requisites --convert-links --domains example.com http://example.com/

Parameters:

  • --wait Wait the specified number of seconds between the retrievals.  We use this option to lighten the server load by making the requests less frequent.
  • --limit-rate Limit the download speed to amount bytes per second. We use this option to lighten the server load and to reduce the bandwidth we consume on our own network.
  • --recursive Turn on recursive retrieving.
  • --no-clobber If a file is downloaded more than once in the same directory, we prevent multiple version saving.
  • --page-requisites This option causes Wget to download all the files that are necessary to properly display a given HTML page.
  • --convert-links After the download is complete, convert the links in the document to make them suitable for local viewing.
  • --domains Set domains to be followed.  It accepts a domain-list as a comma-separated list of domains.