h2status is a trivial (about 50 LOC) bash wrapper to i3status that nevertheless allows to conveniently: (i) write custom modules in bash to add full-fledged json entries to the status bar, (ii) write mouse event handlers in bash with access to the full set of event parameters as bash variables, (iii) arbitrarily transform the final output to cha…

h2status

#!/bin/bash

function status { :; }

function on_event { :; }

function transform { cat; }

function entry {
  echo -ne '{"name":"'$1'","full_text":"'$2'"'${3:+,$3}'},'
}

function cached_status {
  local file=$tmp$1 interval=$2 command=$3
  read_status $1
  [[ -f $file ]] && (( $(date +%s) - $(stat -c %Y $file) < $interval )) && return
  touch $file
  { write_status $1 "$(eval $command)"; } >/dev/null &
}

function read_status {
  [[ -f $tmp$1 ]] && flock -s ${tmp}lock -c "cat $tmp$1"
}

function write_status {
  flock ${tmp}lock -c "echo '$2' > $tmp$1"
  update
}

function update {
  killall -USR1 i3status
}

function event_loop {
  while read line
  do
    eval $(echo "$line" | sed -re 's/^,|\{|\}|"//g' -e 'y/,:/;=/')
    on_event > /dev/null
  done
}

function status_loop {
  read; read; echo -e '{"version":1,"click_events":true}\n['
  while read line
  do
    echo "$line" | sed -r 's/^(,?\[)\{/\1'"$(status)"'{/' | transform
  done
}

tmp=/tmp/h2status_
[[ $1 == "update" && ! $2 ]] && { update; exit 0; }
[[ $1 == "write" && $2 && $3 && ! $4 ]] && { write_status $2 "$3"; exit 0; }
[[ $* ]] && { echo "Usage: h2status [update|write <module> <value>]"; exit 1; }
. ~/.h2statusrc
trap 'rm -f $tmp*; exit' EXIT INT TERM HUP
rm -f $tmp*
i3status | status_loop &
event_loop

h2statusrc

#!/bin/bash

# Use this as a template for your own configuration, to be placed in ~/.h2statusrc.
# All three functions are optional as a default NOP implementation is provided.
# Remember to configure output_format = "i3bar" in ~/.i3status.conf.

function status {
  entry sync_random "SR: $RANDOM" '"color":"$00FF00"'
  entry async_random "ar: $(cached_status async_random 30 'echo $RANDOM')"
}

function on_event {
  case $name in
  async_random) [[ $button == 1 ]] && write_status async_random $RANDOM
  esac
}

function transform {
  sed -r 's/ar:/AR:/'
}