Sep 14 2015
Below an example to show how to remove duplicate objects from an array using underscore in Coffeescript.
My answer is based on the following stackoverflow q/a: http://stackoverflow.com/a/9923961/1688441
array= _.uniq(_.collect(initialArray, (x) -> JSON.stringify x )).map((v) -> JSON.parse(v))
Jun 10 2015
“Revisr is a Git and WordPress database plugin that allows you to keep track of your web projects in version control. Revisr eliminates redundant interfaces in your workflow and allows you to focus on the task at hand.” – Revisr
That sounds well and good. However, configuration required a few steps and below we document them.
It is needed to install git, create certificates, upload them to github, and also set appropriate permissions.
sudo apt-get install git
~/# cd /var/www /var/www# chown www-data .
b) Generate a certificate:
sudo -u www-data ssh-keygen -t rsa
You shouldn’t enter a passphrase and you should see the correct key.
root@server:/var/www/# cd .ssh root@server:/var/www/.ssh# cat id_rsa.pub ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDOL…etc
Go to Github site and upload the certificate.
A) See step 4 of https://help.github.com/articles/generating-ssh-keys/
B) Add your specific key to the github website at: https://github.com/settings/ssh
sudo -u www-data bash ssh -T [email protected]
You should see:
Hi username! You've successfully authenticated, but GitHub does not # provide shell access. Type "Exit" to exit www-data terminal and type "sudo bash" to start root terminal.
Type:
exit sudo bash
Go to the wordpress directory and set the correct permissions. Reference: http://stackoverflow.com/questions/18352682/correct-file-permissions-for-wordpress
chown www-data:www-data -R * # Let apache be owner
find . -type d -exec chmod 755 {} \; # Change directory permissions rwxr-xr-x
find . -type f -exec chmod 644 {} \; # Change file permissions rw-r--r-
git init
B) You should now be able to add and commit files using either the command line or the revisr command panel
chown www-data:www-data -R .[^.]* chown www-data:www-data .
The following steps should do it. Post your comments or questions below or send me an e-mail.
Mar 25 2015
“OpenGL (Open Graphics Library) is a cross-language, multi-platform applicaion
programming interface for rendering2D and 3D vector graphics. The API is typically used to interact with a graphics processor unit (GPU), to achieve hardware accelarated rendering.”
So OpenGL is an open library that let us a draw graphics. In this post we will show how a rookie can build a 
simple game with OpenGL in a C environment. Specifically this game will feature a spacecraft and we will design and implement each part of it using the primitive types of OpenGL . Moreover we will build the environment which includes space, stars , a sun and some planets with the same way. Then we will introduce the way that we can add an animation movement. Finally we will load an asteroid from an object file that will have an orbit towards our spacecraft and the goal will be to avoid the asteroid.
Mar 17 2015
Here is a simple example of using laravel 5 powerful forms to deliver a secure and fast result!
To make our lives easier we need to install the HTML package!
In file /compojer.json we add:
"require": {
"laravel/framework": "5.0.*",
"laravelcollective/html": "~5.0"
},
Next add the service provider and aliases.
In /config/app.php we update the following:
'providers' => [ 'Illuminate\Html\HtmlServiceProvider', ], 'aliases' => [ 'Form'=> 'Illuminate\Html\FormFacade', 'HTML'=> 'Illuminate\Html\HtmlFacade', ],
Mar 17 2015
Here are some tips you might find handy when you think you have done everything according to the tutorials!
In formrequests to authorise access only for registered/signed users we add
use Auth;
public function authorize()
{
if ( !Auth::check() )
return false;
return true;
}
Jan 15 2015
1) Change VCL backend configGo to your vcl file (in my case /etc/varnish/default.vcl). Edit the backend param to point to another server. Also increase the timeouts since it will take longer than accessing localhost.
backend default {
.host = "backupserver.org";
.port = "80";
.connect_timeout = 120s;
.first_byte_timeout = 600s;
.between_bytes_timeout = 60s;
}
sudo varnishd -C -f /etc/varnish/default.vcl
This will notify if any syntax issues exist.
I utilized:
$varnishadm -T localhost:6082
vcl.load reload01 /etc/varnish/default.vcl vcl.use reload01
Nov 27 2014
If you are using RESTClient (and don’t want to switch to CURL) but need to modify the user-client when testing a request, there are two ways:
Since RESTClient is an extension, by default it uses the user-agent of firefox.
As a start we can do a test and access the page http://whatsmyuseragent.com/ through the RestClient.
Oct 2 2014
Below we see an example of calling a mysql script from a file and passing a param.
So make a file with the following (or whatever else you wish):
SET @i = 1;
use databaseName;
SET @pID=@i+100;
SET @partnerID=concat('partner',@pID);
select @i, @pID , @partnerID;
Now, this will print out the values of i, pID, and partnerID.
Below that you could include insert statements or whatever else you wish.
Now how do we call this from bash and set the @i param?
user=root
password=mysqlPass
database=db
for i in {300..400..5}
do
sed -i "1 s/.*/set @i=$i;/" sample.sql
mysql --user="$user" --password="$password" < sample.sql
done
So how does this work?
We use sed to replace the first line completely in sample.sql with a new “set @i=” command containing the i param we want.
We then call mysql and feed the rewritten file.
Another way to do this would be to concatenate the sample.sql contents to the set command, and feed them to mysql in memory.
Aug 6 2014
In this post we will build a server – client application that will get our hands dirty with signals, fork, named pipes and the exec command. This application has a very simple concept:
“Client creates, with a new process, the Server and sends to him terminal commands using as interprocess communication a named pipe (aka fifo pipe)”
Moreover this model must executes terminal commands concurrently and we accomplish that using a signal handler. To be more specific when a client sends through the named pipe a command, the server wakes up because the signal handler receives the SIGCONT signal and changes the wake up variable from 1 to 0. This wake up variable is being used in the server to keep him in sleep mode and not busy waiting. Let’s see a simple example with just the mechanism of it:
Sep 15 2015
Git: How to merge your branch
1. Merging on develop
This method is the most frequently used. It uses the recursive automatic merging method of Git to merge the changes of your branch upon the main develop branch.
2. Merging with rebase
In this method you are applying the develop branch upon yourBranch. If there is a conflict in the process of merging the process stops and you must fix your conflicts manually which may be an advantage some developers. Moreover it does not produce a merge commit message, so it helps to keep the commit history clean.
3. Merging with pull on your branch
By Giannis Kanellopoulos • GIT, GIT version control, Uncategorized 0