Dr. Rolf Freitags Projects

Priority notice
Most of the software i made was developed under Linux, but most of it, including the drivers, can be compiled and used with no or minor modifications under MS-Windows via Cygwin. with the Ioperm driver (package Devel/Ioperm, it has to be started via "ioperm -i") and the appended compiler option -lioperm.

dupmerge - A Program for securely finding and optional linking/deleting duplicate files here.
It it written in C, runs on various platforms (Win32/64 with Cygwin, Unix, Linux etc.) and you can also find it in the grml repository: http://deb.grml.org/pool/main/d/dupmerge/.
You can find a tutorial here.

The original dupmerge author, Phil Karn, has rewritten the original version from scratch, with a new algorithm: http://www.ka9q.net/code/dupmerge/.
So there are now, since december 2008, two actual versions of dupmerge: The karn and the freitag version.
Similar programs are
Duplicate Files Finder - Seems to be similar to dupmerge but with C++ source and a GUI,
fdf - Is written in Perl/C and runs across most platforms (Win32, Unix and probably others). It Uses MD5, SHA1 and other checksum algorithms,
FindRepe - Is written in Java and a command-line tool designed for an eficient search of duplicate files (GNU/Linux, Mac OS X, Unix, Windows,
freedup - Is written in POSIX C and runs across platforms (Windows with Cygwin, Linux, AIX, etc),
fslint - Has commandline interface and GUI,
liten - Is written in Python and has a command line tool and library, using md5 checksums and a novel byte comparison algorithm (Linux, Mac OS X, Unix, Windows),
ua - Is a Unix/Linux command line tool, designed to work with find (and the like), like dupmerge,
and whatpix.

See also the (german) iX article Entdoppeltes Lottchen and the (german) deduplication article "Weniger ist mehr", iX 03/2008, p. 135-137.

There are also other programs for finding duplicate files, e. g. Dupeguru.

For finding similar pictures you need other programs like Diffimg, Findimagedupes or Dupeguru_PE = dupeGuru Picture Edition. Dupeguru_PE can find similar pictures even when they have a different format, e. g. jpg and png.

For finding similar music files and more you can use dupeGuru Music Edition.

Compiler-Tests0 - A minimal compiler test suit, especially for mikrocontroller compiler here.

randomize - An IPv4 number randomizer here.

Public Key Steganography hier.

A driver for the cheap digital multimeter VC 840/VC 820 here.

A driver for the cheap digital LCR meter LCR 612 here.

A driver and powerbox for the cheap relay card 8fa for switching up to eight times 250 V AC / 5 A here.

Frequency and impulse counter program which needs only the parallel port IRQ for frequencies up to 270 kHz here.
The program runs under Linux with the hard realtime patch RTAI.

Some simple programs for the parallel port, e. g. a test to see if the data port is bidirectional and a simulator which simulates heartbeats and treads for an ergometer here.

A driver for reading/writing data on MMC/SD cards with an MSP430 mikrocontroller here.

A PCI template driver for linux with an interrupt handler for Kernel version >= 2.5 here.

A driver for the real time clock DS1339 and some driver stubs for the ARM9 platform here.

Apache2 and proftpd server configuration files with bandwidth and connection limitation for a server with a DSL connection here.

My Geiger counter page here.

My PC battery charging page here.

My physical curios pages: Diffusion Machine.

My Science Myths page.

USB-Sticks.64 GB USB memory stick

Ergänzungen zum Encrypted Root Filesystem Howto .

WARdriving/WARsitting, Bash script for automatic connect to free WiFis . free WiFi

WiFi power measurements .

Mini Howto of WiFi (power) tuning under Linux .

pinger, a program for high resolution pinging and monitoring .

multithreaded_logger, a multithreaded program for logging (data aquisition) under Linux from 1 to many (>32) devices, serial and/or parallel ports, with one posix thread for every device, with defragmentation of serial data packets and with polling for parallel devices .

Bombenbau-Anleitungen für Informatiker .

Other/old projects, e. g. a random number test suit with an entropy test, coupon collectors test etc., are here.