update README.org

README.org

@@ -1,8 +1,13 @@
 * fschl dotfiles
 
-My personal computing environment.
+part of my personal computing environment. mainly contains
+configuration files for sway, some useful addons and system tools
+(git, terminal, ssh, backup). This repository also has some notes on
+security considerations when setting up a Linux system.
 
-** Features
+The relevant things for my workflows can be found in [[https://git.fschl-co.de/fschl/emacs]].
+
+** (future) Features
 
    - reproducable machine setup (GNU Guix)
    - keyboard-based environment (Sway wm)
@@ -25,24 +30,29 @@ My personal computing environment.
 
 *** SSH key generation
 
-     #+BEGIN_SRC bash
+ED25519 keys are favored over RSA keys when backward compatibility ''is not required''.
-       # ED25519 keys are favored over RSA keys when backward compatibility ''is not required''.
+This is only compatible with OpenSSH 6.5+ and fixed-size (256 bytes).
-       # This is only compatible with OpenSSH 6.5+ and fixed-size (256 bytes).
-       $ ssh-keygen -t ed25519 -f ~/.ssh/id_ed25519_host_$(date +%Y-%m-%d) -C "Key to HOST for user-xyz"
 
-       # Fallback for really old systems (why do you still have those??)
+#+BEGIN_SRC bash
-       # RSA keys are favored over ECDSA keys when backward compatibility ''is required'',
+  $ ssh-keygen -t ed25519 -f ~/.ssh/id_ed25519_host_$(date +%Y-%m-%d) -C "Key to HOST for user-xyz"
-       # thus, newly generated keys are always either ED25519 or RSA (NOT ECDSA or DSA).
+#+END_SRC
+
+Fallback for really old systems (why do you still have those??) RSA
+keys are favored over ECDSA keys when backward compatibility ''is
+required'', thus, newly generated keys are always either ED25519 or
+RSA (NOT ECDSA or DSA).
+
+#+BEGIN_SRC bash
   $ ssh-keygen -t rsa -b 8192 -f ~/.ssh/id_rsa_host_$(date +%Y-%m-%d) -C "Key to HOST for user-xyz"
 
   $ ssh-copy-id -i ~/.ssh/<file>.pub -p 22 user@host
-     #+END_SRC
+#+END_SRC
 
 *** GnuPG
 
- - https://wiki.mozilla.org/Security/Key_Management
+- https://wiki.mozilla.org/Security/Key_Management
- - https://keyring.debian.org/creating-key.html
+- https://keyring.debian.org/creating-key.html
- - https://wiki.debian.org/Subkeys
+- https://wiki.debian.org/Subkeys
 
  ~~/.gnupg/gpg.conf~:
 
@@ -86,18 +96,25 @@ My personal computing environment.
    - [ ] move to ansible for easier modularization of setup
    - [ ] OR: give GUIX a shot
 
-** Moving to Arch
+** Notes on Arch
 
    - official repository setup: https://wiki.archlinux.org/title/Official_repositories#multilib
      - ~multiplib~ is required for wine
    - Sound troubleshooting: https://wiki.archlinux.org/title/Advanced_Linux_Sound_Architecture/Troubleshooting#HDMI
    - Skype, VSCode: use ~yay~
 
+** TODO Fedora
+
+- fedora project
+- different Desktop/Workstation spins (Gnome, KDE, sway...)
+- =dnf= package manager, install updates on reboot
+- "Atomic Desktop", uses Fedora/RedHat CoreOS with rpm-ostree + flatpaks
+
 ** NEXT Moving to Guix
 
 - btrfs for snapshots, easier backups
 - encrypted =/boot= + =/home= partitions
-- separate subvolumes for =/gnu=, =var=, =swap=
+- separate subvolumes for =/gnu=, =/var=, =swap=
 
 - [ ] MOVE: https://www.draketo.de/software/package-guix.html
 
@@ -118,3 +135,18 @@ convert multiple .png files into multipage pdf with downscaling
           -extent 1240x1753 -gravity center \
           -units PixelsPerInch -density 150x150 multipage.pdf
 #+end_src
+
+lower resolution:
+#+begin_src bash
+  convert filePrefix*.png -resize 620x876 \
+          -extent 629x876 -gravity center \
+          -units PixelsPerInch -density 100x100 multipage.pdf
+#+end_src
+
+combine multiple pdf file into one multipage file
+#+begin_src sh
+  gs -dBATCH -dNOPAUSE -q -sDEVICE=pdfwrite -sOutputFile=result.pdf sourceFilePrefix-*.pdf
+#+end_src
+
+I read the answer like ImageMagick uses ghostscript internally.
+source: https://stackoverflow.com/questions/14738911/imagemagick-combine-2-generated-pdfs-into-1-multi-page-file