[SOLVED] Possible to modify lock screen to show battery percentage?

[SilenceIsG0lden]

I've looked around but couldn't find anything to this -- could very well be I didn't look in the right places.

Whenever I have my Mac plugged in to charge the battery, the lock screen is visible whenever I don't actively use it. I appreciate that there is an icon in the upper right corner of the lock screen indication that the battery is being charged -- but I am looking for a way to get the percentage showing. That way I could make a guess how much longer it needs to charge without having to unlock the system.

Can anyone point me in the right direction or the solution?

Thanks!!

[Hoser Rob]

I did a search and the only thing I can find is an applet for Cinnamon that was started, apparently didn't work right, and was abandoned. This was from 2016. Not encouraging.

[Koentje]

Yes, that's possible.
Place this script in ~/bin and make an autostart application.

Code: Select all

#!/bin/bash
##########################################################
#                                                        #
#  Shows battery status in screensaver                   #
#                                                        #
##########################################################

# Path to hwmon for BAT0
device=$(ls -1 /sys/class/power_supply/BAT0 | grep hwmon)
hwmonpath="/sys/class/hwmon/$device"
if [ "$device" = "" ]; then
  echo -e "\e[31;1m* Can not find any BAT0 hardware monitor in /sys/class/hwmon, exiting script.\e[0m"
  exit 1
fi

# Start loop
while :
do
    # Checks if screensaver is active
    ss=$(xdg-screensaver status)
    if [ "$ss" = "enabled" ]; then
      capacity=$(cat $hwmonpath/device/capacity)
      dconf write /org/cinnamon/desktop/screensaver/default-message "'Battery $capacity%'"
    fi
   
    # Sleep 10 seconds and check again
    sleep 10
done

This script runs in a loop, checks if screensaver is enabled and if so gets capacity_level from BAT0 and shows it under your clock. The screensaver updates the text only every minute when the clock is updated! First start can take a few seconds before the battery text apears.

[SilenceIsG0lden]

Yes, that's possible.

Thank you, Koentje, for trying to help me!
I followed your instructions: created a file, copied the contents of the script into it and saved it, opened /bin as root and copied it into it. Then opened Startup Applications and added the script, simply as a link to the file, picked a 30 second delay after bootup.

I then rebooted. Started the lock screen (via power button, which I set in power management to start the lock screen). Sadly, the battery percentage is not showing up; I waited a few minutes.

I then looked at the script in more detail; however, my knowledge is rather limited. What I discovered, though, is that the folder /sys/class/hwmon/ has no '$device' items -- instead there are 6 links to folders, all numbered, starting with 0: /sys/class/hwmon/hwmon0/, /sys/class/hwmon/hwmon1/, etc.

All of those folders have a modified time stamp from when I last booted up. Their contents are not identical either, one has just 4 items, and one has as many as 20 - though some of those are again folders with more items. Am I understanding your script correctly that in this case the script exits, since it doesn't find the hardware monitor? Or did I get that wrong? I'm not getting any error message to that effect, though. Would it appear in the screensaver on the lock screen? (Am still confused if it's lock screen or screensaver - since the only screensaver that's not just black/blank seems to be the lock screen... )

If I go into any of those folder, e.g.: hwmon1, I seem to end up in an endless loop if I follow the first folder each time:
/sys/class/hwmon/hwmon1/device/hwmon1/device/hwmon1/device/hwmon1/device/hwmon1/device/hwmon1/device/hwmon1/device/hwmon1 -- it just keeps going like this; I stopped clicking.

Anything I could provide from my system so you can help me further? Or did you already spot a mistake I made? Maybe in setting up the script in the autostart app?

It seems like it should work, since I do have the hardware monitor. I don't know why that should matter, but to be on the safe side: I also use the Slimbook Battery software, with 3 different profiles, to extend my battery life (or "turbo charge" it for starting Google docs...). Could that interfere?

Thanks again!

[Koentje]

Place the script in ~/bin not /bin! In other words, place it in your home's bin folder and try again. And see if it can be executed and is owned by you! Let me know if still nothing happens..

[SilenceIsG0lden]

Place the script in ~/bin not /bin! In other words, place it in your home's bin folder and try again.

Oh! That would make a difference. I don't seem to have one in my home folder. So, shall I make one? If so, would it be as a ".bin" or "bin"?

[Koentje]

Place the script in ~/bin not /bin! In other words, place it in your home's bin folder and try again.

Oh! That would make a difference. I don't seem to have one in my home folder. So, shall I make one? If so, would it be as a ".bin" or "bin"?

bin

And see if you have these lines in your ~/.bashrc file

Code: Select all

# set PATH so it includes user's private bin if it exists
if [ -d "$HOME/bin" ] ; then
    PATH="$HOME/bin:$PATH"
fi

This way the bin folder is in your PATH.

[SilenceIsG0lden]

[...]bin
[...]
And see if you have these lines in your ~/.bashrc file
[...]
This way the bin folder is in your PATH.

Thank you for your continued help! I've done both of those things -- and took the file with the script out of the other place + deleted the autostart entry for it + created a new one with the new link.
But still no luck: Rebooted, started screensaver, moved the mouse to active the login screen, waited a few minutes, nothing. The battery icon just sits there as usual.

Please confirm: every time you refer to the home folder, it is in fact 'home\{username}' - correct?

What about the fact that I don't have a device in '/sys/class/hwmon' and only those numbered virtual (as in they are all links) hwmon0 - hwmon5 folders?

[Koentje]

Yes what else could be 'home'? Of cource it is your home directory... /home/$USER.
And yes again, /sys/class/hwmon only contains links.. because the real hwmon folders are in the devices folder, but linked to /sys/class/hwmon.

What does the script say when you start it from the terminal... error message or does it go into the loop?

[SilenceIsG0lden]

Yes what else could be 'home'?

Well, if I go one level up I have '/home/{username}' and '/home/.ecryptfs' -- I just wanted to be sure. (Sometimes the smallest misunderstandings can lead to extensive troubleshooting.)
[...]

And yes again, /sys/class/hwmon only contains links.. because the real hwmon folders are in the devices folder, but linked to /sys/class/hwmon.

I'm sorry; I don't want to annoy you. I was just trying to understand the script. I followed the links, and only the hwmon2 (i.e. /sys/class/hwmon/hwmon2/device) has a 'capacity' file; hwmon5/device has 'capacity_level'.

What does the script say when you start it from the terminal... error message or does it go into the loop?

Seemingly nothing happened. But when I wanted to close the terminal window, it said there was still something running. So I pressed the power button to call up the screensaver -- and voila! OK. This is weird. Literally nothing else changed except for me running the script once in the terminal. Could that have kicked off something? It is persistent; I just rebooted.

THANK YOU, Koentje!!

[Koentje]

I followed the links, and only the hwmon2 (i.e. /sys/class/hwmon/hwmon2/device) has a 'capacity' file; hwmon5/device has 'capacity_level'.

What did the name file say in both hwmon folders?

Seemingly nothing happened. But when I wanted to close the terminal window, it said there was still something running.

So the loop was activated.

So I pressed the power button to call up the screensaver -- and voila! OK. This is weird. Literally nothing else changed except for me running the script once in the terminal. Could that have kicked off something? It is persistent; I just rebooted.

It did not klick off anything, you prabably did not wait long enough the first time for the text to come up.. as i said, could take a while the first time.

THANK YOU, Koentje!!

You're welcome!

[SilenceIsG0lden]

What did the name file say in both hwmon folders?

hwmon2's is the battery, BAT0; hwmon5's is hidpp_battery_0. No idea what that could be. You?

Btw, I was too premature in my celebration -- I had plugged the Macbook in when it was at 34% charge. It's fully charged now, but the % in the lockscreen is not changing, no matter how often I go in there or how long I wait. I ran the script in a terminal, and now it updated to 100% - even though by now I'm down to 89%.

Any idea what could be going on?

[Koentje]

hwmon2's is the battery, BAT0; hwmon5's is hidpp_battery_0. No idea what that could be. You?

I guess you have a battery powered mouse or keyboard?

Btw, I was too premature in my celebration -- I had plugged the Macbook in when it was at 34% charge. It's fully charged now, but the % in the lockscreen is not changing, no matter how often I go in there or how long I wait. I ran the script in a terminal, and now it updated to 100% - even though by now I'm down to 89%.
Any idea what could be going on?

I don't know, maybe it's a mac thing? On my Dell Latitude i get an update every minute. If i set a custom time in screensaver settings and add seconds to it, i get an update every second! %H:%M:%S.

I changed the script a little so now you see if AC is pluggen in.

Code: Select all

#!/bin/bash
##########################################################
#                                                        #
#  Shows battery status in screensaver                   #
#                                                        #
##########################################################

# Path to hwmon for BAT0
hwmonpath="/sys/class/hwmon/$(ls -1 /sys/class/power_supply/BAT0 | grep hwmon)"
while :
do

     ss=$(xdg-screensaver status)

     if [ "$ss" = "enabled" ]; then
       capacity=$(cat $hwmonpath/device/capacity)
       ac=$(upower -d | grep 'online: ' | awk '{print $2}')
       if [ "$ac" = "yes" ]; then
         ac="[AC]"
       else
         ac=""
       fi

       # Uncomment below line to test on terminal
       #echo "$ac Battery $capacity%"
       
       dconf write /org/cinnamon/desktop/screensaver/default-message "'$ac Battery $capacity%'"
     fi
  
  sleep 10
done

You can also test it first on the terminal and uncomment the #echo "$ac Battery $capacity%" line. Start the script, start screensaver, plug your ac adapter, wait 10 seconds, then unplug ac adapter, wait 10 seconds, then exit screensaver. See if there is some battery output on the terminal.

[SilenceIsG0lden]

hwmon2's is the battery, BAT0; hwmon5's is hidpp_battery_0. No idea what that could be. You?

I guess you have a battery powered mouse or keyboard??

Insert facepalm. Yes, a wireless mouse.

You can also test it first on the terminal and uncomment the #echo "$ac Battery $capacity%" line. Start the script, start screensaver, plug your ac adapter, wait 10 seconds, then unplug ac adapter, wait 10 seconds, then exit screensaver. See if there is some battery output on the terminal.

This is so odd. I tested with the uncommented line, and everything went as it should; it even updated the battery percentage in the screensaver, with the added [AC]. I changed the file in the BIN folder with your new script. Rebooted -- and the percentage shown in the screensaver was stuck at the number it was before I rebooted. I ran the script again in the terminal, went into the screensaver, came back in to look at the terminal window -- and it showed 108%, the 109%, but the battery was actually at 89%. When I started the screensaver again, it also showed 109% there. I haven't closed the terminal window, and it's steadily counting up there. My battery is at 100% now, but still plugged in. The script output is at 112%.

Thank you very much for your efforts, but I think there's something particular about the MacBook that prevents your script from working correctly, as you have already suggested. Wouldn't be too surprising, I suppose. I won't change the solved status, though, as it may well work for others, and I'm now moving on without a solution. (First world problems...)

[Koentje]

I have used this script the past 2 weeks on my own laptop and it works great for me. So this is something mac indeed.
But can you test something for me please. Maybe i can change something in the script for it to work.
When the laptop percentage goes beyond 100%, can you run upower -d | grep 'percentage' for me and see if this tells the correct or also incorrect numbers?

[Koentje]

Anyway, in case upower does show the correct value, then below script should work!

Code: Select all

#!/bin/bash
##########################################################
#                                                        #
#  Shows battery status in screensaver                   #
#                                                  V2    #
##########################################################

up=$(which upower)

while :
do

     ss=$(xdg-screensaver status)

     if [ "$ss" = "enabled" ]; then
       capacity=$($up -d | grep 'percentage' | awk '{print $NF}' | head -n1)
       ac=$($up -d | grep 'online: ' | awk '{print $2}')
       if [ "$ac" = "yes" ]; then
         ac="[AC]"
       else
         ac=""
       fi

       # Uncomment below line to test on terminal
       #echo "$ac Battery $capacity%"

       dconf write /org/cinnamon/desktop/screensaver/default-message "'$ac Battery $capacity'"
     fi

  sleep 10
done

[SilenceIsG0lden]

Anyway, in case upower does show the correct value, then below script should work!

Yes, upower does show the correct value. Sadly, though, the script still doesn't work when saved in the Bin folder. As in the first version of your script, after changing the script in the Bin folder and after rebooting, it permanently shows the percentage of the last time I ran the script in the terminal. (With the only difference being that it now shows 4 digits after the comma.)

Could the problem lie elsewhere, not in the script itself, but how its handled by the system? Pure speculation, as I have no clue, just based on the fact that it works when running it in the terminal. It just seems like it or a part of it is not being "picked up" by Cinnamon. If I go to the entry in Startup Applications and click the run now arrow, it doesn't change anything either. Still stuck at that percentage.

I'm willing to troubleshoot some more, since I know how this kind of challenge can be churning away in the back of one's mind. And who knows, maybe it'll work out in the end!

[Koentje]

Maybe upower for your device gives other layout. Can you post output of upower -d

[SilenceIsG0lden]

Code: Select all

Device: /org/freedesktop/UPower/devices/line_power_ADP1
  native-path:          ADP1
  power supply:         yes
  updated:              Wed 14 Feb 2024 14:25:59 (2607 seconds ago)
  has history:          no
  has statistics:       no
  line-power
    warning-level:       none
    online:              no
    icon-name:          'ac-adapter-symbolic'

Device: /org/freedesktop/UPower/devices/battery_BAT0
  native-path:          BAT0
  vendor:               Newer Tech
  model:                A1495
  power supply:         yes
  updated:              Wed 14 Feb 2024 15:09:07 (19 seconds ago)
  has history:          yes
  has statistics:       yes
  battery
    present:             yes
    rechargeable:        yes
    state:               discharging
    warning-level:       none
    energy:              14.1488 Wh
    energy-empty:        0 Wh
    energy-full:         43.364 Wh
    energy-full-design:  38.48 Wh
    energy-rate:         12.7576 W
    voltage:             7.228 V
    charge-cycles:       687
    time to empty:       1.1 hours
    percentage:          32.628%
    temperature:         27.6 degrees C
    capacity:            100%
    technology:          lithium-ion
    icon-name:          'battery-good-symbolic'
  History (charge):
    1707944946	32.628	discharging
    1707944944	32.662	discharging
    1707944942	32.696	discharging
    1707944940	32.747	discharging
    1707944938	32.782	discharging
  History (rate):
    1707944946	12.758	discharging
    1707944944	10.012	discharging
    1707944942	11.537	discharging
    1707944940	13.068	discharging
    1707944938	12.432	discharging

Device: /org/freedesktop/UPower/devices/mouse_hidpp_battery_0
  native-path:          hidpp_battery_0
  model:                Wireless Mouse
  serial:               1c-e9-ee-76
  power supply:         no
  updated:              Wed 14 Feb 2024 15:08:44 (42 seconds ago)
  has history:          yes
  has statistics:       yes
  mouse
    present:             yes
    rechargeable:        yes
    state:               discharging
    warning-level:       none
    battery-level:       normal
    percentage:          55% (should be ignored)
    icon-name:          'battery-low-symbolic'

Device: /org/freedesktop/UPower/devices/DisplayDevice
  power supply:         yes
  updated:              Wed 14 Feb 2024 15:09:06 (20 seconds ago)
  has history:          no
  has statistics:       no
  battery
    present:             yes
    state:               discharging
    warning-level:       none
    energy:              14.1488 Wh
    energy-full:         43.364 Wh
    energy-rate:         12.7576 W
    charge-cycles:       N/A
    time to empty:       1.1 hours
    percentage:          32.628%
    icon-name:          'battery-good-symbolic'

Daemon:
  daemon-version:  0.99.17
  on-battery:      yes
  lid-is-closed:   no
  lid-is-present:  yes
  critical-action: HybridSleep

[Koentje]

Ok, thanks! That made some things more clear.. you have another path to your AC device then my laptop. And your battery power has decimals indeed.. you can uncomment a line to get rid of the decimals.
The script now checks for the right path to BAT0 and AC. And it logs more stuff, your environment, when started, some upower things and when it goes into a loop waiting for the screensaver.. etc.
Call it ss-battstat3.sh and place it in your ~/bin folder. Then change the autostart application to point to the correct script. Logout and login again and it now has created a ~/bin/ss-battstat.log.

Code: Select all

#!/bin/bash
##########################################################
#                                                        #
#  Shows battery status in screensaver                   #
#                                                  V3    #
##########################################################
x=1
scrpath=$(readlink -f $0)
workdir=$(dirname $scrpath)
log="$workdir/ss-battstat.log"
datum=$(date +'%d-%m-%Y %H:%M')

# GET PATH TO UPOWER
up="$(which upower)"
# GET PATH TO BATTERY DEVICE
bat0=$($up -e | grep 'BAT0')
# GET PATH TO POWER SUPPLY
ps=$($up -e | grep 'line_power_')

echo -e "\n*** Starting battery status in screensaver on $datum ***\n" > "$log"
echo -e "------------------------------------------------------------------\n" >> "$log"
echo -e "$(env)\n" >> "$log"
echo -e "------------------------------------------------------------------\n" >> "$log"
echo -e "upower path = $up" >> "$log"
echo -e "BAT0 path = $bat0" >> "$log"
echo -e "AC path = $ps\n" >> "$log"
echo -e "$(upower -d)\n" >> "$log"
echo -e "------------------------------------------------------------------\n" >> "$log"
echo -e "*** Going into loop ***" >> "$log"

while :
do

     # GET SCREENSAVER STATUS
     ss=$(xdg-screensaver status)

     if [ "$ss" = "enabled" ]; then
       if [ "$x" = "0" ]; then echo "* Screensaver active!" >> "$log"; x=1; fi

       # GET BATTERY PERCENTAGE
       capacity=$($up -i "$bat0" | grep 'percentage' | awk '{print $NF}')

       # UNCOMMENT BELOW FOR BATTERY PERCENTAGE WITHOUT DECIMALS
       #capacity=$(echo "$capacity" | awk -F'.' '{print $1"%"}')

       # IS AC ADAPTER CONNECTED
       ac=$($up -i "$ps" | grep 'online:' | awk '{print $NF}')

        if [ "$ac" = "yes" ]; then
          ac="[AC]"
        else
          ac=""
        fi

       # UNCOMMENT BELOW LINE TO TEST ON TERMINAL  (or see ./ss-battstat.log)
       #echo "$ac Battery $capacity"

       # SET DCONF SCREENSAVER MESSAGE
       dconf write /org/cinnamon/desktop/screensaver/default-message "'$ac Battery $capacity'"
       echo "Dconf set to:  $(dconf read /org/cinnamon/desktop/screensaver/default-message)" >> "$log"
     else
       if [ "$x" = "1" ]; then echo "* Screensaver inactive, waiting to get active.." >> "$log"; x=0; fi
     fi

  # SLEEP 10 SECONDS BEFORE WE CHECK AGAIN
  sleep 10
done