How to list all PostgreSQL databases and their sizes in MB

You must provide proper database name and user:


File: gistfile1.txt
-------------------

psql -c "SELECT pg_database.datname, pg_database_size(pg_database.datname), pg_size_pretty(pg_database_size(pg_database.datname)) FROM pg_database ORDER BY pg_database_size DESC;" -d  

How to restore or update Arduino Mega 2560 firmware?

This tutorial is for Linux users. It will cover step by step how to flash an Arduino with miscellaneous firmwares (it’s for absolute beginners, you should know Linux quite good to perform this). I use cheap cloned board called Mega Keyes model Mega 2560 R3 with Atmega 2560 16AU. You can also use this method to unbrick your faulty Arduino.

Continue reading How to restore or update Arduino Mega 2560 firmware?

How to find Raspberry Pi using MAC address

When you want to find your headless but networked Raspberry Pi and you’re lazy like me use nmap:

sudo nmap -sP 192.168.1.0/24 | awk '/^Nmap/{ip=$NF}/B8:27:EB/{print ip}'

Mask /24 means that addresses from 192.168.1.0 to 192.168.1.254 will be searched. You can extend that to /16 if you don’t know subnet of your device.

How to obscure your WordPress version and troll the attacker a little…

One of my company’s WordPress installations has been hacked by Turkish hackers recently. After quick investigation I’ve found that script version was little bit old (not a very popular website, mea culpa, not updated very often). In case you didn’t know, WordPress is bundled with readme file by default. I’ve found that malicious scripts or people use that to determine your version’s branch. So I’ve decided to Troll them a little bit… Continue reading How to obscure your WordPress version and troll the attacker a little…

How to add Bower component when it’s not in the repository?

Sometimes component that you want to use in your project isn’t available in Bower repo. There is a way to install it, even in very specified version. Go to project’s Github, in my case it’s here. Copy URL from the browser, and paste it somewhere. Now go to relases and click commit id that you’re interested in (this random blue colored string):

After that you’ll see full commit id, in this case it’s fef978b279c546923ad4f4118acea4d503e7596c. Paste that to the end of repository URL you’ve copied earlier. Remember to prefix it with # char and add .git to the URL:

https://github.com/bfintal/Counter-Up.git#fef978b279c546923ad4f4118acea4d503e7596c

Finally mix it with your bower.json file. Here’s full example:

{
	"name": "Realhero report",
	"description": "Report template based on New Age",
	"main": "index.js",
	"authors": ["Konrad Fedorczyk"],
	"license": "ISC",
	"homepage": "http://realhe.ro",
	"private": true,
	"ignore": ["**/.*", "node_modules", "bower_components", "test", "tests"],
	"dependencies": {
	    "bootstrap": "^3.3.7",
	    "font-awesome": "^4.6.3",
   	 	"jquery": "^1.11.3",
   	 	"simple-line-icons": "^2.3.2",
   	 	"morris.js": "^0.5.1",
   	 	"jqvmap-fedek6": "https://github.com/fedek6/jqvmap.git#774c12a57916ab82e17406203bb41522dfe0e38b",
   	 	"Counter-Up": "https://github.com/bfintal/Counter-Up.git#fef978b279c546923ad4f4118acea4d503e7596c"
	}
}

Look at the last line of dependencies part, here’s component that I’ve added.

Permission denied when script is trying to execute ps_files_cleanup_dir

This is pretty common problem. I’ve encountered it on recent version of the Debian operating system. When you see something like that:

Notice:  session_start(): ps_files_cleanup_dir: opendir(/var/lib/php5/sessions) failed: Permission denied (13) in /mnt/www-data/htdocs/raportMNW/inc/bryanjhv/slim-session/src/Slim/Middleware/Session.php on line 110

You can fix that easily with following Linux commands:

sudo nano /etc/php5/apache2/php.ini

Now use CTRL+W to find following string session.save_path and configure it like that:

session.save_path = "/tmp"

Save your file using CTRL+X and restart Apache2 service:

sudo service apache2 restart

And voilà!