Nostalgic Java Tools


Package mdvl-java-nostalgic-tools provides a few Tools that are included in MDVL for nostalgia only, because their functionality is provided by other, and well-maintaned tools. Still, the tools are very simple and run on Windows as well as Linux which does not always hold for their better counterparts.

Compile all tools (requres Ant and a JDK) by running

$ ant

Package them together (on Debian systems with suitable depnendencies installed) by running

$ ant package

The following sections describe the individual tools in man-page style.



cmdcolors – Display color capabilities of the console (max 16 colors)




Outputs a table with certain useful ANSI escape sequence colors. Does not display all possible combinations but some that are considered most useful.

cmdcolors screenshot

See also

colortest-16b(1) – does the same thing but better in all regards: The output is less convoluted and it reminds the user of the correct escape sequence syntax.



netread – Listen to data incoming on sockets and display it in hex.


netread [port]


Listens on the specified port by using a socket. Whenever data comes in, it prints them out in HEX. Once the connection closes, a new socket is created.

The default port is 5971 unless otherwise specified.


Open a terminal and run netread:

$ netread
NetRead 1.0, Copyright (c) 2012
For further info send an e-mail to

Listening on port 5971
Press enter to terminate application.

 68  65  6c  6c  6f  20  77  6f  72  6c  64  0a                        

 6e  65  77  20  77  6f  72  6c  64  0a                                

In another terminal, send some messages:

$ echo hello world | nc 597
$ echo new world | nc 5971

See also

nc(1), xxd(1) and the shell together do the same:

$ while true; do nc -l 5971 | xxd; echo; done
00000000: 6865 6c6c 6f20 776f 726c 640a            hello world.

00000000: 6e65 7720 776f 726c 640a                 new world.



version_change – Compute checksums of a directory’s files to detect changes.


version_change display DATABASE DIR
version_change accept  DATABASE DIR


This tool recursively computes the SHA-256 checksums of all files found below directory DIR and stores them in a CSV file DATABASE when invoked with accept.

When invoked with display, it will compute all the checksums and based on that, output a list of files that were either added, changed or removed.


See also

find(1), sort(1), diff(1), sha256sum(1)

Combine them as follows:

# accept
find . -type f -exec sha256sum {} + | sort > state_old.txt
# display
find . -type f -exec sha256sum {} + | sort > state_new.txt
diff state_old.txt state_new.txt
# accept (without recomputation!)
mv -f state_new.txt state_old.txt

If cut and paste are added to swap the columns in the state_ files, it behaves even more like version_chnage in that it will become possible to detect the difference between changed and added/deleted files.



vcp – Copy directory trees while displaying a lot of progress info




Copies directory SRC to DST. Two modes of invocation are to be distinguished:

During Invocation, vcp displays a lot of progress information. Some of the ideas (speed diagram) have been taken up by Windows 10’s copy function while others (progress bars separate for number of files and data) are quite uncommon.

Visual Copy does not retain any file attributes nor modification times.

Visual Copy screenshot

Exit Status

1 failed to list some directories or incorrect commandline options
2 failed to copy some files
64 Bug

See also

rsync(1) – does everything better except for the progress bars.

# Command to replace
vcp /root/ /tmp/test

# Very reliable, works efficiently over netcat to transfer large
# structures. No resumption upon interruption.
tar -C /root -c . | pv | tar -C /tmp/test -x

# Slightly slower (?) than tar, but allows resuming the transfer
# and displays the names of the files as transferred
rsync -av /root/ /tmp/test/



xmlparser – Commandline tool to parse XML files with Java


xmlparser FILE


This program attempts to parse the given XML file using a SAXParser that is validating and XInclude aware. In case of invalid files, the exception is printed to console, otherwise no output is shown.

See also

xmlstarlet(1) which can provide a similar use with xmlstarlet validate. Website 5 (1.0.1) – no Flash, no JavaScript, no Webfont, no Copy Protection, no Mobile First. No bullshit. No GUI needed. Works with any browser.

Created: 2020/10/14 22:41:12 | Revised: 2022/09/18 21:15:44 | Tags: mdvl, package, java, legacy | Version: 1.0.0 | SRC (Pandoc MD) | GPL

Copyright (c) 2020 For further info send an e-mail to

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with this program. If not, see <>.