`batfetch` errors out with `power_now': No such file or directory`, `energy_now': No such file or directory` and `/1000000: syntax error: operand expected (error token is "/1000000")`.

[dreirund]

When I run batfetch, checkout just from today (git commit hash 196329f), it errors out for me with

  🬭🬭🬭█████🬭🬭🬭
  █         █  <censored>@<censored>-winmax2
  █         █  model   Standard SR Real Battery
cat: '/sys/class/power_supply/BAT*/energy_now': No such file or directory
cat: '/sys/class/power_supply/BAT*/power_now': No such file or directory
/usr/bin/batfetch: line 140: [: =: unary operator expected
(standard_in) 1: syntax error
  🮂🮂🮂🮂🮂🮂🮂🮂🮂🮂🮂  charge  100% h 0m
cat: '/sys/class/power_supply/BAT*/power_now': No such file or directory
/usr/bin/batfetch: line 153: /1000000: syntax error: operand expected (error token is "/1000000")

ls -1dF /sys/class/power_supply/BAT0/*:

/sys/class/power_supply/BAT0/alarm
/sys/class/power_supply/BAT0/capacity
/sys/class/power_supply/BAT0/capacity_level
/sys/class/power_supply/BAT0/charge_full
/sys/class/power_supply/BAT0/charge_full_design
/sys/class/power_supply/BAT0/charge_now
/sys/class/power_supply/BAT0/current_now
/sys/class/power_supply/BAT0/cycle_count
/sys/class/power_supply/BAT0/device@
/sys/class/power_supply/BAT0/hwmon2/
/sys/class/power_supply/BAT0/manufacturer
/sys/class/power_supply/BAT0/model_name
/sys/class/power_supply/BAT0/power/
/sys/class/power_supply/BAT0/present
/sys/class/power_supply/BAT0/serial_number
/sys/class/power_supply/BAT0/status
/sys/class/power_supply/BAT0/subsystem@
/sys/class/power_supply/BAT0/technology
/sys/class/power_supply/BAT0/type
/sys/class/power_supply/BAT0/uevent
/sys/class/power_supply/BAT0/voltage_min_design
/sys/class/power_supply/BAT0/voltage_now

My system has current_now and charge_now instead of power_now and energy_now.

I have made a script that handle the different cases and displays the correct units -- you can feel inspired by it if you want:
linux-terminal-battery-status.sh.

[dreirund]

I still get such an error:

  🬭🬭🬭█████🬭🬭🬭
  █         █  <censored>@<censored>-winmax2
  █         █  model   Standard SR Real Battery
/usr/bin/batfetch: line 143: [: =: unary operator expected
(standard_in) 1: syntax error
  █    󱐌    █  charge  100% h 0m
/usr/bin/batfetch: line 156: /1000000: syntax error: operand expected (error token is "/1000000")

It turns out that I do not have /sys/class/power_supply/BAT0/power_now, but on my system it is current_now.

Same with energy_now, which is not present on my system; but charge_now is present on my system.

Regards!

[sokai]

FYI: As you can see, energy_now + power_now (used by get_charge()) are missing, BUT all values can (now?) be found in uevent …!

BR

~ ❯ nix run github:ashish-kus/batfetch
  🬭🬭🬭█████🬭🬭🬭
  █         █  sokai@host
  █         █  model   SMP DELL G8VCF33
/nix/store/w567m0x1mykskh7ff4fhkdi7gsdn1s4m-batfetch/bin/batfetch: line 143: [: =: unary operator expected
(standard_in) 1: syntax error
  █    󱐌    █  charge  90% h 0m
/nix/store/w567m0x1mykskh7ff4fhkdi7gsdn1s4m-batfetch/bin/batfetch: line 156: /1000000: syntax error: operand expected (error token is "/1000000")

~ ❯ uname -a
Linux host 6.12.21 #1-NixOS SMP PREEMPT_DYNAMIC Fri Mar 28 21:03:33 UTC 2025 x86_64 GNU/Linux

~ ❯ ll /sys/class/power_supply/BAT0/
total 0
-rw-r--r-- 1 root root 4096  3. Apr 15:44 alarm
-r--r--r-- 1 root root 4096  3. Apr 14:58 capacity
-r--r--r-- 1 root root 4096  3. Apr 15:44 capacity_level
-rw-r--r-- 1 root root 4096  3. Apr 15:44 charge_control_end_threshold
-rw-r--r-- 1 root root 4096  3. Apr 15:44 charge_control_start_threshold
-r--r--r-- 1 root root 4096  3. Apr 14:58 charge_full
-r--r--r-- 1 root root 4096  3. Apr 14:58 charge_full_design
-r--r--r-- 1 root root 4096  3. Apr 14:58 charge_now
-rw-r--r-- 1 root root 4096  3. Apr 15:44 charge_types
-r--r--r-- 1 root root 4096  3. Apr 14:58 current_now
-r--r--r-- 1 root root 4096  3. Apr 14:58 cycle_count
lrwxrwxrwx 1 root root    0  3. Apr 14:58 device -> ../../../PNP0C0A:00
-r--r--r-- 1 root root 4096  3. Apr 15:44 eppid
drwxr-xr-x 3 root root    0  3. Apr 14:58 hwmon1
-r--r--r-- 1 root root 4096  3. Apr 14:58 manufacturer
-r--r--r-- 1 root root 4096  3. Apr 14:58 model_name
drwxr-xr-x 2 root root    0  3. Apr 15:44 power
-r--r--r-- 1 root root 4096  3. Apr 14:58 present
-r--r--r-- 1 root root 4096  3. Apr 14:58 serial_number
-r--r--r-- 1 root root 4096  3. Apr 14:58 status
lrwxrwxrwx 1 root root    0  3. Apr 14:58 subsystem -> ../../../../../../class/power_supply
-r--r--r-- 1 root root 4096  3. Apr 14:58 technology
-r--r--r-- 1 root root 4096  3. Apr 14:58 temp
-r--r--r-- 1 root root 4096  3. Apr 14:58 type
-rw-r--r-- 1 root root 4096  3. Apr 14:58 uevent
-r--r--r-- 1 root root 4096  3. Apr 14:58 voltage_min_design
-r--r--r-- 1 root root 4096  3. Apr 14:58 voltage_now

~ ❯ cat /sys/class/power_supply/BAT0/uevent 
DEVTYPE=power_supply
POWER_SUPPLY_NAME=BAT0
POWER_SUPPLY_TYPE=Battery
POWER_SUPPLY_STATUS=Charging
POWER_SUPPLY_PRESENT=1
POWER_SUPPLY_TECHNOLOGY=Li-poly
POWER_SUPPLY_CYCLE_COUNT=0
POWER_SUPPLY_VOLTAGE_MIN_DESIGN=7600000
POWER_SUPPLY_VOLTAGE_NOW=8450000
POWER_SUPPLY_CURRENT_NOW=3753000
POWER_SUPPLY_CHARGE_FULL_DESIGN=6842000
POWER_SUPPLY_CHARGE_FULL=6842000
POWER_SUPPLY_CHARGE_NOW=4874000
POWER_SUPPLY_CAPACITY=71
POWER_SUPPLY_CAPACITY_LEVEL=Normal
POWER_SUPPLY_MODEL_NAME=DELL G8VCF33
POWER_SUPPLY_MANUFACTURER=SMP
POWER_SUPPLY_SERIAL_NUMBER=2433

Update: uevent also is available for AC … (Maybe uevent is the future?)

~ ❯ cat /sys/class/power_supply/AC/uevent 
DEVTYPE=power_supply
POWER_SUPPLY_NAME=AC
POWER_SUPPLY_TYPE=Mains
POWER_SUPPLY_ONLINE=1