Battery status in tmux status bar in FreeBSD
           ============================================

  Last edited: $Date: 2021/12/08 20:09:49 $


                            Ratpoison
                            ---------

  On  my  FreeBSD  laptop  I  switched  back  from the i3 window
  manager to the ratpoison window manager. I have  been  running
  ratpoison for more than a decade and only switched to i3 about
  two years ago.  So, now I am back at ratpoison.

  In ratpoison, I have no dock or permanent visible status bar.

                               tmux
                              -----

  I start tmux from my `.xinitrc` so it is always running in  my
  first  ratpoison window (window number zero). Most of the time
  I am in this window.

  So, the tmux status bar is a useful  location  for  displaying
  the battery status.

  See also: gopher://box.matto.nl/0/start_tmux_from_xinitrc.txt

                     Just enough information
                     -----------------------

  I don't need much information to be shown in the status bar.

  When  the  charger  is  connected,  I want to know how far the
  charging is.

  When on battery, I want to know  what  the  remaining  battery
  time is.

  ### Script

  For this, I created a small script `~/bin/battery.sh``:

    #!/bin/sh

    STATE=`sysctl -n hw.acpi.battery.state`

    if [ $STATE -eq 2 ]; then
       echo "chg" $(sysctl hw.acpi.battery.life | cut -d : -f 2) "%"
    else
       echo "batt:" $(apm | grep time | head -n 1 | cut -d : -f 2,3) "h"
    fi

  ### Format

  This results in the following format:

  - When the charger is connected: `chg 86 %`
  - When on battery: `batt: 3:44 h`

  For me, this is just enough.

                            ----------

  In `.tmux.conf` there is the following line:

    set -g status-right "#(~/bin/battery.sh) | %A %d-%b-%y %H:%M"

  This  displays  the  battery  status, the day of the week, the
  date and the time (in 24 hours format) at the  right  side  of
  the status bar, like `chg 88 % | Saturday 04-Dec-21 21:40`.

                            Resources
                            ---------

  See  also  this  page: 
  https://coderwall.com/p/bqw_tq/battery-status-in-tmux-status-bar