~derf

You have reached the personal homepage of an entity commonly known as derf / derfnull / Birte Friesel. Hi! 👋

If you are looking for the more professional side of me, you may take a look at my Publications (see below) or head directly to my work homepage: Dr. Birte Kristina Friesel @ Universität Osnabrück

Resources

Contact

You can reach me by E-Mail (d​erf@fina​lr​ewind.org) and on IRC (derf0 @ OFTC, hackint). My PGP key for E-Mail encryption is 64FE6EC0 55560F9E F13A3044 19E6E524 EBB177BA. I occasionally post stuff on the Fediverse (@derf@social.skyshaper.org).

The remainder of this page duplicates a curated sub-set of projects and the latest blog entries.

Projects

Travel::Routing::DE::DBRIS v0.11
Interface to bahn.de itinerary service 
> dbris 'Eichlinghofen H-Bahn, Dortmund' 'Dortmund Hbf'

19.01. 16:51  (00:21)  17:12   .  Bus  S

Bus 440 → Oespel S-Bahnhof, Dortmund
16:51 (+1)  ab  Eichlinghofen H-Bahn, Dortmund
16:56 (+1)  an  Oespel S-Bahnhof, Dortmund

Fußweg 46m  (≈ 3 min.)
S 1 → Dortmund Hbf   .
17:01 (+5)  ab  Dortmund-Oespel  2
17:12 (+2)  an  Dortmund Hbf  7
Travel::Routing::DE::HAFAS v0.10
Interface to HAFAS itinerary services 
> hafas 'Eichlinghofen H-Bahn, Dortmund' 'Dortmund Hbf'

00:15        Schw-B HB5  (0:03)  S 1

Schw-B HB5 → Universität S-Bahnhof, Dortmund
21:51  ab  Eichlinghofen H-Bahn, Dortmund
21:55  an  Universität S-Bahnhof, Dortmund

Walk 37m  (approx. 3 minutes)
S 1 → Dortmund Hbf
21:58  ab  Dortmund Universität: 2
22:06  an  Dortmund Hbf: 4
Travel::Routing::DE::EFA v2.24
Interface to EFA itinerary services 
> efa Essen Martinstr Düsseldorf Hbf
14:34 ab  Essen Martinstr.: Bstg. 1      Straßenbahn 108      Essen Altenessen Bf Schleife
14:38 an  Essen Hauptbahnhof: Bstg. 1

14:47 ab  Essen Hauptbahnhof: 2          R-Bahn RE11 (RRX)    Düsseldorf Hbf
15:24 an  Düsseldorf Hbf: 10
Travel::Status::DE::DBRIS v0.27
Interface to bahn.de public transit monitors 
> dbris-m 'Bochum Hbf'
06:39  ( +7)   ICE 843                             Berlin Hbf  5
06:39  ( +7)   ICE 853                             Berlin Hbf  5
06:51  (+19)       S 1                              Essen Hbf  7
06:37  ( +1)   ICE 527                            München Hbf  3
Zug fährt abweichend mit nur einem Zugteil. Die Wagen 31 - 39 entfallen.
Travel::Status::DE::HAFAS v6.25
Interface to HAFAS public transit monitors 
> hafas-m 'Hamburg Dammtor'
13:49  ( +1)  RE 7     Flensburg                  3
13:49  ( +1)  RE 7     Kiel Hbf                   3
13:49         S 5      Buxtehude                  2
13:50  ( +4)  Bus 5    Nedderfeld, Hamburg
13:50         U 1      Ohlstedt, Hamburg
Travel::Status::DE::EFA v3.20
Interface to EFA public transit monitors 
> efa-m -s VVO Dresden Hbf
13:40 ( -2)  5      66           Lockwitz
13:41        3      3         .  Wilder Mann
13:44        4      3         .  Coschütz
13:44        6      66           Freital-Deuben
13:46 ( +4)  6      360          Kurort Altenberg Bahnhof
13:46        5      360          Dresden Ammonstraße / Budapester Straße
13:48 ( +1)  1      7         *  Weixdorf
13:51        1      10        .  Tolkewitz
13:52        Gl.10  RE3          Hof Hbf
db-infoscreen
Public Transit Departure Monitor
TODO!
feh v3.11.2
imlib2 based image viewer
TODO!
msp430-etv
MSP430 EnergyTrace viewer
TODO!
travelynx
Public Transit Travel Logger
TODO!
zlib-deflate-nostdlib
C/C++ embedded decompression library
TODO!

News

2026-03-30 00:00

Travel::Routing::DE::DBRIS v0.11

Travel-Routing-DE-DBRIS-0.11.tar.gz (signature)

  • Segment: Add is_cancelled accessor
  • dbris: indicated cancelled stops and segments
2026-03-28 00:00

Travel::Routing::DE::DBRIS v0.10

Travel-Routing-DE-DBRIS-0.10.tar.gz (signature)

  • Handle wonky backend timestamps during DST transition (e.g. CET to CEST)
  • dbris: -m / --modes-of-transit: identifiers are now case-insensitive
  • Connection::Segment: new accessors: dep_stop, arr_stop
  • dbris: Show arrival date for cross-midnight connections
2026-03-28 00:00

Travel::Status::DE::DBRIS v0.27

Travel-Status-DE-DBRIS-0.27.tar.gz (signature)

  • Handle wonky backend timestamps during DST transition (e.g. CET to CEST)
2026-03-28 00:00

Travel::Status::DE::VRR v3.20

Travel-Status-DE-VRR-3.20.tar.gz (signature)

  • Handle wonky backend timestamps during DST transition (e.g. CET to CEST)
2026-03-27 00:00

Travel::Status::DE::DBRIS v0.26

Travel-Status-DE-DBRIS-0.26.tar.gz (signature)

  • Update train names (patch by Lili Chelsea Urban)
  • dbris: Indicate when we are waiting for a request
2026-03-05 00:00

Travel::Status::DE::DBRIS v0.25

Travel-Status-DE-DBRIS-0.25.tar.gz (signature)

  • ...::Formation::Sector: Remove cube_meters and cube_percent accessors. The corresponding data is no longer provided by the backend.
2026-02-28 00:00

Travel::Status::DE::VRR v3.19

Travel-Status-DE-VRR-3.19.tar.gz (signature)

  • EFA->new: add optional num_results argument (default: 40)
  • efa: add -n / --num-results option
2026-02-23 00:00

Travel::Routing::DE::DBRIS v0.09

Travel-Routing-DE-DBRIS-0.09.tar.gz (signature)

  • Increase default timeout to 20 seconds to deal with bahn.de's WAF now delaying most requests by about 10 seconds.
2026-02-22 00:00

Travel::Status::DE::DBRIS v0.24

Travel-Status-DE-DBRIS-0.24.tar.gz (signature)

  • Increase default timeout to 20 seconds to deal with bahn.de's WAF now delaying most requests by about 10 seconds.
2026-02-08 00:00

Travel::Status::DE::IRIS v2.04

Travel-Status-DE-IRIS-2.04.tar.gz (signature)

  • Update station and meta databases for rail replacement service around Düsseldorf / Wuppertal / Hagen / Dortmund
2026-02-07 00:00

Travel::Status::DE::IRIS v2.03

Travel-Status-DE-IRIS-2.03.tar.gz (signature)

  • Add missing geocoordinates for two stations
  • Update meta database
2026-02-06 00:00

Travel::Routing::DE::DBRIS v0.08

Travel-Routing-DE-DBRIS-0.08.tar.gz (signature)

  • Deutsche Bahn have rolled out a rather aggressive Akamai EdgeSuite WAF configuration, and too-frequent requests made with this module may cause the corresponding IP address or range to be blocked for yet-to-be-determined amounts of time. Send more plausible requests with randomized user agent strings and additional headers to maybe hopefully slightly reduce the risk of this happening.
  • New dependency: UUID
2026-02-06 00:00

Travel::Status::DE::DBRIS v0.23

Travel-Status-DE-DBRIS-0.23.tar.gz (signature)

  • Deutsche Bahn have rolled out a rather aggressive Akamai EdgeSuite WAF configuration, and too-frequent requests made with this module may cause the corresponding IP address or range to be blocked for yet-to-be-determined amounts of time. Send more plausible requests with randomized user agent strings and additional headers to maybe hopefully slightly reduce the risk of this happening.
  • New dependency: UUID
2026-02-06 00:00

Travel::Status::DE::IRIS v2.02

Travel-Status-DE-IRIS-2.02.tar.gz (signature)

  • Update station database
2026-02-05 00:00

Travel::Status::DE::HAFAS v6.25

Travel-Status-DE-HAFAS-6.25.tar.gz (signature)

  • Update service definitions. Fixes BVG service.