Software - Notes on my favorite programs

• If you just want to display the cover image of the currently playing album, you only have to add albumArt.jpg to the directory containing the music files. Some players require (used to require) this file to be named cover.jpg.
• This may/may not work with other file formats (not tested).

1. get a song as MP3 :
   yt-dlp --extract-audio --audio-format mp3 --audio-quality 0 https://music.youtube.com/watch?v=Oj0sOJ4BVJ0
2. find a cover art image to embed (works better with square-shaped images)
3. embed the image :
   ffmpeg -i song_withoutImage.mp3 -i image.jpg -map 0 -map 1 -c copy -disposition:v:1 attached_pic song_withImage.mp3
4. should you need to retry embedding the image, VLC will display a cached version of the embedded image. You may clear its cache in ~/.cache/vlc

Reboot-proof method (source) :

For the current session only (source) :

1. my Debian Buster workstation boots normally and displays the graphical login window, as usual
2. I enter my credentials, then
3. the screen turns black
4. there's nothing more I can do, the CTRL-Alt-Fn keys have no effect

• this Debian machine is actually a VirtualBox guest running on a Windows 7 host
• the Windows 7 machine itself is a notebook using 2 external screens via its docking station
• both Windows 7 and Debian are configured so that the Debian host uses the 2 external screens, in full-screen mode. This has worked for years.
• a few minutes before having this problem, I deplugged/replugged the notebook from its docking station, resulting in Windows 7 completely "forgetting" everything about the 2 external screens. I had to re-detect + reconfigure them
• at the next boot of the Debian machine, the "black screen" issue described above started

A few things to remember :

Solution :

1. Select the cells containing the line breaks you want to remove (or don't select anything if you want to alter the whole datasheet)
2. CTRL-h (or Edit | Find & Replace)
3. In the Find field, enter \n
4. In the Replace field, enter whatever you would like to replace line breaks with
5. Then click Other options
6. Tick Current selection only if you wish to alter selected cells only
7. Tick Regular expressions
8. Then Replace (or Replace All if you're brave enough)

• What is X2Go ?
• Server install on Debian
  • Preliminary notes
  • Install on Jessie
  • Install on Stretch
• Client install
  • on Windows 7
  • on Stretch
    • Bug : the connection closes instantly : Status: finished

What is X2Go ?

Server install on Debian (source, procedure for Stretch) :

Client install

Usage :

1. View the boot.properties file :
   cat /appli/projects/myApplicationName/weblogic_10.0MP1/wl-domains/DOMAINE-WLS-MYAPP/boot.properties

   #Mon Mar 21 17:00:17 MET 2011
   password={3DES}sRO9OiEXAWNw2AE7UfkAxw\=\=
   username={3DES}kpclVYTJKNeNXN1ZPNzfNQ\=\=

   And save the encrypted password for later.
2. Move to the security child directory of the directory containing the boot.properties file :
   cd /appli/projects/myApplicationName/weblogic_10.0MP1/wl-domains/DOMAINE-WLS-MYAPP/security/
3. Make sure there is a SerializedSystemIni.dat file in this directory (this file will be read by the script below) :
   ls -l SerializedSystemIni.dat
4. In this directory, create a Python script :

   cat << EOF > script.py
   from weblogic.security.internal import *
   from weblogic.security.internal.encryption import *
   
   # Remind user about how to use
   raw_input("Please ensure SerializedSystemIni.dat is in the current directory now, and press ENTER to continue.")
   
   # Get encryption service
   encryptionService = SerializedSystemIni.getEncryptionService(".")
   clearOrEncryptService = ClearOrEncryptedService(encryptionService)
   
   # Get user to enter password
   pwd = raw_input("Enter encrypted password (Eg. {3DES}Y1fA34S...): ")
   
   # Remove unnecessary escape characters
   preppwd = pwd.replace("\\\\", "")
   
   # Decrypt the password
   print "Recovered password is: " + clearOrEncryptService.decrypt(preppwd)
   EOF

   There are extra \ in the line : preppwd = pwd.replace("\\\\", "") to escape the regular \ when writing the file with cat and heredocs.
   The real line will be : preppwd = pwd.replace("\\", "")

5. Then run :
   • as webadm, the user owning the WebLogic processes : ${WL_HOME}/common/bin/wlst.sh script.py
   • as root : /logiciels/bea/weblogic_10.0MP1/wlserver_10.0/common/bin/wlst.sh script.py
     (or /export/logiciels/bea/weblogic_10.0MP1/wlserver_10.0/common/bin/wlst.sh ???)
   ... and enter the encrypted password when prompted.
6. Enjoy !

For all SVN commands requiring login and password :

svn --username userName --password 'password' svnCommand

Download sources from the SVN repository :

svn checkout http://SVN_repository_url/project/tagName[@revision] destinationDirectory

Register new files into the SVN repository :

svn add newFile1 newFile2 ...

Unregister files from the repository (details) :

• schedule files for deletion from repository upon next commit + remove files from working copy : svn del /path/to/oldFile1 /path/to/oldFile2 ...
• delete files from the repository (immediate commit) : svn del protocol://url/to/oldFile1 ...

Apply local changes to the repository :

• save ALL changes : svn commit -m "description of changes"
• OR save listed files only : svn commit file1 file2 ... -m "description of changes"

Update working copy after a commit by one of the project contributors :

svn update

Get information on working copy :

svn stat (or svn status)
Parameters :

Parameter	Usage	Example
--depth empty|files|immediates|infinity	Investigate not only the current directory	svn stat --depth infinity

Output :

Output	Meaning
? file	file is unknown to SVN
D file	file has been marked for deletion with svn del
M file	file has local modifications that are not yet saved into the repository

Information on local file :

svn info localFile

Discard local changes : roll back to the previous repository version :

svn revert path/to/file

Roll back to any previous repository version (source : 1, 2, SVN book) :

1. Testing : svn merge --dry-run -r currentRevision:revisionToRevertTo path/to/file
2. Same as above without --dry-run
3. Verify that the change is removed : svn diff
4. svn commit -m "Reverted to revision xxx."

Show differences between the working copy and the latest revision :

svn diff file

Differences between 2 revisions :

svn diff -r rev_n:rev_m file

Show modification author :

svn blame file

Show commit messages :

svn log file

The cat method :

The ffmpeg method (source) :

ffmpeg + cat (tested on Quicktime to MPEG):

1. Pick a font from xfontsel. Get its specification string into the clipboard with Select.
2. Append your chosen font specification string into ~/.Xresources :

   xterm*font:	*-fixed-medium-r-*-*-18-*

3. Restart X or reload settings immediately : xrdb -merge ~/.Xresources