to visually sort images under Linux doesn’t seem to be a trivial task. I duckduckgo‘ed for a long time and had a look at various image and file managing applications before finding gthumb. And even there, you first need to create a “catalog” and within the catalog a “library” which will finally allow you to manually sort your images. All of which is not documented.

Once you’ve sorted your images, you’d possibly want to export the sorting? Again, no trace of any help or documentation: gthumb catalogs are saved under $HOME/.local/share/gthumb/catalogs/foobar.catalog.

Tomáš Pospíšek

Since I found Michel de Boer’s explanation of many of the fundamental SIP concepts in his 2005 dutch presentation of the Twinkle SIP phone very short and easy to follow - contrary to a lot of other material about SIP out there - I’ve translated it to english.

Here it is: Twinkle - a SIP softphone for Linux

Well, sometimes one wonders why people write tools that wheight a megabyte, when it’s easy to stick together one or two tools with a script and have the same thing.

Here’s a ruby script that generates a ping latency graph (target is google):

#!/usr/bin/ruby
#
# based on
#   http://oss.oetiker.ch/rrdtool/prog/rrdruby.en.html example
# with help of the tutorial
#   http://oss.oetiker.ch/rrdtool/tut/rrdtutorial.en.html
# and the docu
#   http://oss.oetiker.ch/rrdtool/doc/rrdcreate.en.html
# 
# placed in the public domain by Tomáš Pospíšek

require "RRD"

$rrd    = `mktemp /tmp/tmp.XXXXXXXX`.chomp
$grafik = `mktemp /tmp/tmp.XXXXXXXX`.chomp
$start  = 0

def now()
  Time.now.to_i
end

def create()
  $start=now()
  RRD.create(
    $rrd,
    "--start", "#{$start - 1}",
    "--step", "#{1}",       # every 1s
    "DS:pinglatency:GAUGE:10:0:200", # 10s of missing data are OK, min=0, max=200 (ping time)
    "RRA:AVERAGE:0.5:1:#{60*30}") # 60 seconds * 30 minutes
  puts "RRD database created #{$rrd} at #{$start}"
  puts "Your graph is at #{$grafik}"
end

def ping_latency
   `ping -c 1 -n -w 1 google.com` =~ /.* time=(\d+)/
  # 64 bytes from 74.125.43.147: icmp_seq=1 ttl=52 time=31.6 ms
  return $1
end

def update()
  puts "updating #{$rrd} with #{now()}:#{ping_latency()}"
  RRD.update($rrd, "#{now()}:#{ping_latency()}")
end

def generate_gfx()
  # puts "generating graph #{$grafik}"
  RRD.graph(
   "#{$grafik}",
    "--title", " Ping latency to Google",
    "--x-grid", "SECOND:10:MINUTE:1:MINUTE:2:0:%X",
    "--start", $start.to_s,
#    "--end", # -> now
    "--interlace",
    "--imgformat", "PNG",
    "--width=450",
    "DEF:pinglatency=#{$rrd}:pinglatency:AVERAGE",
    "AREA:pinglatency#00b6e4:ms")
end

#main
create()
while(true)
  update()
  generate_gfx()
  sleep 1
end

It generates a graph like this:

Copying a DVD under Linux wasn’t a problem for a long time. I always used k3b. However lately I failed to copy a DVD.

k3b would say: "failed to retireve all CSS keys" or in german "es konnten nicht alle CSS Schlüssel geholt werden". k9copy would say: "libdvdread: Error cracking CSS key for /VIDEO_TS/VTS_03_1.VOB (0x0031ccb6)!!"

First I thought k3b didn’t have access to libdvdcss. However it turns out that aparently some DVD drives won’t return data from some sections of a disc if the region code of the drive is not set.

My drive is a “HL-DT-ST DVDRAM GSA-T20N”. After setting the region code with "regionset" I was able to copy the DVD. Thanks a lot to the population of the internet that allowed me to slowly progress to a solution…

In short:

$ sudo apt-get install regionset
$ regionset
[...]
Would you like to change the region setting of your drive? [y/n]:y
Enter the new region number for your drive [1..8]:2
New mask: 0xFFFFFFFD, correct? [y/n]:y
Region code set successfully!

Region codes can be found here

Tomáš Pospíšek