Welcome to Rob Groen's website

The Internet Jigsaw

Internet and internet systems are like one big jigsaw. Every piece has to be on the right place. If just one piece isn't right than you won't get the result you hoped for.

E-commerce specialist

I am a E-commerce specialist and can help you with many questions about this fantastic way of selling you products or services. In the late '90 I started a web shop for selling white-goods over the Internet on the Dutch marked. I was the first one who did that and there was no software like Drupal of OS-Commerce. I had to invent it all by myself. It was a great time!.
The shop was very successful and some day a big company made me an offer that I couldn't refuse. So I sold my e-commerce business.

Now I use my knowledge to advice and help other e-commerce companies to get better, grow and make more profit. My strength is the combination between technique and commerce.

Linux specialist

I am a Linux specialist and work with Linux since 1997. I am using mainly Debian based distributions like Debian and Ubuntu.
Please let me help you to find the pieces you need and how to stuck them together.Visit my Linux Tips & Trick page to see some helpful solutions.

Scheveningen Luxemburg Scheveningen

Classic SLS Rally

Since 1995 I drive with the technical service and repair group in the Classic SLS Rally. this Rally is for old car dated before 1975 and they drive from Scheveningen, a famous city on the west coast from The Netherlands, to downtown Luxembourg city and back again.

The rally includes 2 nightly stays in Belgium.

SLS Rally Medaille

Portfolio overview

A overview with some of my website projects. I prefer building websites in Drupal, Joomla and OS-Commerce.


Latest Tips & Tricks

My latests solutions for Linux software problems.
(English Only)

Multiple images to one paged pdf file

If you want to make one pdf-file that exist of multiple A4 pages with one each page a jpg-image.

Create a directory and drop all jpg images in that directory.
Launch this command in that directory

convert *.jpg -resize 575x823^> -bordercolor '#ddd' -border 5x5 -page A4 -background white -extent 595x842 "FILE NAME.pdf"

Grep emailaddress from IMAP dir with UNDELIVERABLE messages

Case

You send newsletter and get a hole buns of UNDELIVERABLE email back in your INbox. You find this irritating and want to cleanup your newsletter database.

To do so you probably need a list with all email addresses you want to un-subscribe.

Solution

  • First create a new IMAP directory.

Compress PDF files

Compressing PDF file can be don on many different ways. This is how I got the best result. By compressing a 14.4MB file with big HiRes pictures to a 2.7MB file for screen use.

In Ubuntu (Linux) open the PDF in a PDF viewer

Print the PDF to a file with the file -> print -> ps, name the file output_print_to_file.ps ( this makes a large postscript file)

Check for valid of invalid emailaddresses with egrep

Xterm.png

If you want to check if a file, like a csv-file with e-mail-addresses for a newsletter, contains invalid formatted email-addresses then you can use this egrep command.

egrep "\w+([._-]\w)*@\w+([._-]\w)*\.\w{2,4}" emial.csv -vn

Input file email.csv is a file containing all the email-addresses.

ZPanel creates multiple backups on one day

Suddenly my ZPanel began making multiple backups on one day. Looking at the filename of the backup it looks like the backups are made 1 sec after another.

Backup has file names like this

zadmin_Oct-18-2014_051006.zip
zadmin_Oct-18-2014_051007.zip
zadmin_Oct-18-2014_051008.zip


Fotografie

Fotografie is al sinds mijn jeugd een hobby. In de jaren '70 fotografeerde ik met een 2-hands grootbeeld spiegelreflex camera. Echt een oudje en ondanks zijn leeftijd een prima camera. Dat was in die tijd normaal dat je naast je camera ook een aparte, losse belichtingsmeter bij je had. Immers met de camera kon je niets ander dan scherpstellen, de sluitertijd en het diafragma instellen.

Nikon-D90.jpg