BaSzErr - blog:2026:01:11

2026-01-11_-_redundant_internet_at_home

anonymous@undisclosed.example.com (Anonymous) — Sun, 11 Jan 2026 12:25:29 +0000

2026-01-11 - redundant internet at home

for some years now i work 95% remotely, visiting office only a few times a year. this means i want to have network connection as stable as it can be. while i do have fiber optics and while it's almost perfect wrt availability, 1-2 times a year there are moment when internet is down… and with my luck, this can strike in a very bad moment.

to combat that i decided to get a redundant network connection. my 2nd ISP is a mobile provider. therefor i have 2 WANs – the main via my PC-router one and a RasPi with USB modem attached. on a home router i have a simple script that pings a set a predefined IPs to check if internet connection is there or not. if it fails, it moves to a secondary link. it goes like this:

#!/bin/bash
set -eu -o pipefail
app=$(basename "$0")
 
function is_alive # <0:iface>
{
  local i=1
  local n=5
  for addr in $(sort -R /etc/startup/allowed_external_hosts.ips | head "-$n")
  do
    timeout 4 ping -c 2 -I "$1" "$addr" > /dev/null 2>&1 && return 0
    echo "$app: ping $addr via $1 failed ($i/$n)"
    ((++i))
  done
  echo "$app: looks like $1 is dead..."
  return 1
}
 
function set_default # <0:metric_pri> <1:metric_sec>
{
  echo "$app: setting $if_pri=$1 vs. $if_sec=$2"
  (
    set +e
    set -x
    ip r del "${rule_pri[@]}"
    ip r del "${rule_sec[@]}"
    ip r add "${rule_pri[@]}" metric "$1"
    ip r add "${rule_sec[@]}" metric "$2"
    systemctl stop  openvpn
    systemctl start openvpn
    sleep 2 # give VPN some time to reconnect, so that the routing table is shown properly
    ip r
  )
  echo "$app: switchover completed"
}
 
function set_pri
{
  set_default 2000 3000
}
 
function set_sec
{
  set_default 3000 2000
}
 
if_pri=wan0
if_sec=wan1
 
rule_pri=( $(ip r | grep "^default .* $if_pri\>" | sed -e 's/ metric .*//' -e 's/ *$//') )
rule_sec=( $(ip r | grep "^default .* $if_sec\>" | sed -e 's/ metric .*//' -e 's/ *$//') )
 
current=unknown
 
trap set_pri EXIT
 
while sleep 1
do
  if is_alive "$if_pri"
  then
    if [ "$current" = pri ]
    then
      sleep 3
    else
      set_pri
      current=pri
    fi
    continue
  fi
 
  if is_alive "$if_sec"
  then
    if [ "$current" = sec ]
    then
      sleep 11
    else
      set_sec
      current=sec
    fi
    continue
  fi
 
  echo "$app: both interfaces seem to be dead - that's bad..."
done

the script is meant to be ran as a systemd service.

since pinging is possible via an explicitly-specified interface, we can check if a given link is up or not, w/o changing any network settings. then, if link switch is required, it's enough to swap metric of 2 interfaces (here: wan0 and wan1) and restart VPN, so that it connects via a new interface… and that's it. works like a charm for a long time now, with fairly fast switching in case of a problem. it's also quite noise resistant, as many different IPs are used randomly and multiple IPs are checked before deciding to fail over.

2026-01-11_-_rsync_and_defaults

anonymous@undisclosed.example.com (Anonymous) — Sun, 11 Jan 2026 11:57:10 +0000

2026-01-11 - rsync and defaults

i really like rsync. there's sth brilliant in how it's (conceptually) simple and yet so powerful. there are however gotchas. recently i've noticed, when i sync data between some of my machines, there are certain files that are ~always re-synced (despite not being changed) as well as there are files that sync once, and then cause errors to sync after that.

to debug this it's worth using –itemize-changes that outputs a reason why a given file was synced. format is a bit cryptic, but after a moment with docs, it turned out that there's a bit of time offset (we're talking some tens of milliseconds, to be clear!) between source and target machines. this caused those “unfortunate” files to be always synced. the answer? use –times flag to rsync, so that it also copies creation / modification times from source. this way time offset between machines does not matter. that solved the 1st problem.

the second one is… odd. turns out that git does not give write permissions to object files in .git dir, as these are not expected to ever change after writing. fine locally, but a bit problematic when rsyncing repo, as there the file can change (e.g. resuming previous partial send). to fix this one –chmod=u+rw was added to rsync, so that remote copy has always R/W access for user at least. this allows to error-less sync things.

nice. these were quite some discoveries to be made. my only question – could we ask for a better defaults? the current ones just cause confusion…

btw: more rsync tips can be found on help_cmds repo, as usual.

2026-01-12_-_easy_emoji_under_linux

anonymous@undisclosed.example.com (Anonymous) — Mon, 12 Jan 2026 19:55:04 +0000

2026-01-12 - easy emoji under linux

recently i was wondering what's the best way to type in emoji under linux. some key bindings would be nice, to the common ones… and it turned out that using Wayland and sway DM it's very easy! :)

1st we need a script that's using wtype to simulate inserting characters from keyboard. e.g.:

#!/bin/bash
set -euo pipefail
for name in "$@"
do
  case "$name" in
    "cold_swet")     wtype "😅" ;;
    "grimacing")     wtype "😬" ;;
    "grin")          wtype "😁" ;;
    "hushed")        wtype "😯" ;;
    "innocent")      wtype "😇" ;;
    "rotfl")         wtype "🤣" ;;
    "scream")        wtype "😱" ;;
    "skull")         wtype "💀" ;;
    "sunglasses")    wtype "😎" ;;
    "thinking")      wtype "🤔" ;;
    "speak_no_evil") wtype "🙊" ;;
    "hear_no_evil")  wtype "🙉" ;;
    "see_no_evil")   wtype "🙈" ;;
    "spock")         wtype "🖖" ;;
    "thumbs_up")     wtype "👍" ;;
    "thumbs_down")   wtype "👎" ;;
    "rocket")        wtype "🚀" ;;
    "poo")           wtype "💩" ;;
    "rolling_eyes")  wtype "🙄" ;;
    "fire")          wtype "🔥" ;;
    "snowman")       wtype "⛄" ;;
    *)               wtype "?"  ;;
  esac
done

then add key bindings to Sway's config (i use right alt, as this is default for inserting polish national characters, too) in ~/.config/sway/config:

[...]
# emoji
bindsym Mod5+g       exec emoji grin
bindsym Mod5+shift+g exec emoji grimacing
bindsym Mod5+r       exec emoji rotfl
bindsym Mod5+Shift+r exec emoji rocket
bindsym Mod5+p       exec emoji spock
bindsym Mod5+Shift+p exec emoji poo
bindsym Mod5+t       exec emoji thinking
bindsym Mod5+h       exec emoji scream
bindsym Mod5+Shift+h exec emoji hushed
bindsym Mod5+u       exec emoji thumbs_up
bindsym Mod5+d       exec emoji thumbs_down
bindsym Mod5+l       exec emoji cold_sweat
bindsym Mod5+k       exec emoji skull
bindsym Mod5+j       exec emoji sunglasses
bindsym Mod5+i       exec emoji innocent
bindsym Mod5+y       exec emoji rolling_eyes
bindsym Mod5+f       exec emoji fire
bindsym Mod5+w       exec emoji snowman
[...]

…and off we go! :)

you might have noticed that not all emoji have a binding. that's ok, as you can still use the script from command line with e.g.: emoji fire and you get your character inserted where needed! :)

also a note – while in theory you could put wtype directly to Sway's config, it's make it harder to read, as there are no inline comments and in text mode, many emojis are hard to read or do not show at all (i.e. just a hex code).