Create test files of specific size

Sometimes you need file of an exact site for testing purpose like an email attachment.

Here is how you make them in Linux command line:

dd if=/dev/zero of=file_5Mb.txt bs=1k count=5120
dd if=/dev/zero of=file_7Mb.txt bs=1k count=7168
dd if=/dev/zero of=file_8Mb.txt bs=1k count=8192
dd if=/dev/zero of=file_8.8Mb.txt bs=1k count=9011

How-To Change SMTP port Exim


Last week I would change the SMTP port from my Exim4 email server in Amsterdam.


I am using my laptop on many network over many providers. Also the network from in The Netherlands that blocked all SMTP (port 25) traffic outside here one network.

How To Split PDF forms


If you want to split your PDF forms you can use the pdf-toolkit with the burst command. The output are pdf-files for each page one.

pdftk INPUT_FILE.pdf burst

The result are multiply PDF files for each page one file.

Script to Wakeup machine over LAN


If you want to wakeup remote machine over a LAN and automatically start the remote desktop viewer this is a solution.

The script first send a magic package to wakeup the remote machine. After that is checking every 4 second is the remote desktop is available on the machine. This done by telnet-ting to port 5900.

How To Kill Pulseaudio when audio stucks


Steps to kill pulsaudio.
Solution for when there is no sound and the soundservers is blocked by pulseaudio

On my desktop machine I have frequently a problem with Pulseaudio. After playing a flash movie (Youtube) it happens very often that I have no audio anymore on my Moviplayers like Movie Player or VLC.

The solution for this problem is to kill all Pluseaudio processes.

How To Resize multiply images to prefered size


If you want to resize multiply images to a other (smaller) size you can use this command.

It's not recommend to enlarge pictures because that will have a negative effect on the quality of the enlarged image.

time find ./ -maxdepth 1 -iname '*.jpg' -exec convert '{}' -resize 500 '../big/{}' \;

* time: gives you the time the command was busy. This is optional.

How To add subtitles to a movie and save is to a new file


Add subtiltes to a new outputfile.
incl. resizeable subtitles, percentage from picture hight. So it can be shown on the Philips media player

mencoder -fontconfig -subfont-text-scale 3 -ovc lavc INPUT-FILE.avi -sub "" -oac copy -o OUTPUT-FILE.avi

How To Add subtitles in Mplayer


Playing a movie with "hot" added subtitles.

Use this command:

mplayer -fontconfig -subfont-text-scale 3 INPUT-FILE.avi -sub ""