Help me understand a thing or two

Rrvp · Feb 22, 2021

pfr Is there a neater/simpler way to get the same output without sed of awk ?

UP=$(uptime)
UP=${UP#*up}
UP=${UP%%,*}
echo $UP

yeti · Feb 22, 2021

pfr Is there a neater/simpler way to get the same output without sed of awk ?

$ UP=$(set - $(uptime) ; echo $3 days)
$ echo $UP
39 days

pfr · Feb 22, 2021

rvp ️ This does the trick. The only thing which is strange is, I like to encase each output in [square brackets] however when I do this I get a trailing space after the first bracket like so: [ 14 minutes]. This triggers my OCD slightly I've just added the bracked to the echo line at the end like this:

UP=$(uptime)
UP=${UP#*up}
UP=${UP%%,*}
echo [$UP]

yeti Nice! However, I shutdown my laptop when I'm done using it so no need for "days"

yeti · Feb 23, 2021

pfr yeti Nice! However, I shutdown my laptop when I'm done using it so no need for "days"

Without "days" it even is shorter... ;-)
I only kept it because your original awk/sed dance had it.

pfr · Mar 9, 2021

Ok, new query...

I'd like for my laptop to warn me when my battery is low. Visual notifications are useless and I would rather have an audible beep (which I noticed isn't available on NetBSD) or some other sound once the battery gets below 10%.

I guess a shell script could do this but would a system service need to be started at boot in order to monitor the battery status?

Nneubaer · Mar 9, 2021

pfr Why not run the script from cron every minute or so? And battery level can be checked with envstat I think.

Rrvp · Mar 10, 2021

pfr I would rather have an audible beep (which I noticed isn't available on NetBSD) or some other sound once the battery gets below 10%.

Call your script which plays a wav file or somesuch in /etc/powerd/scripts/sensor_battery. That script is called with a warning-under event when the SOC reaches 10% and a critical-under event when it reaches 1%. There is also a low-power event there to shutdown the system.

pfr · Mar 10, 2021

neubaer I thought about using cron but dont really want scripts running every minute if it isn't necessary. I think using a powerd scrips as RVP suggeests will work better.

rvp Awesome, thanks. Is there any way to use a built in hardware beep/bell rather than a .wav file?

Rrvp · Mar 12, 2021

pfr Is there any way to use a built in hardware beep/bell rather than a .wav file?

Set device permissions (as root--once only):

chmod go+rw /dev/speaker

Then, in your script:

echo -n CDEF >/dev/speaker

See spkr(4) for more info.

pfr · Mar 13, 2021

rvp
I assumed I could just add this to the /etc/powerd/scripts/sensor_battery script like so but it didn't work.
Does it need to be called from a separate script?

#!/bin/sh -
#
#       $NetBSD: sensor_battery,v 1.8 2014/03/13 00:50:55 christos Exp $
#
# Generic script for battery sensors.
#
# Arguments passed by powerd(8):
#
#       script_path device event sensor state_description
#
case "${2}" in
normal)
        logger -p warning \
            "${0}: (${3}) capacity reached normal state [${1}]" >&1
        exit 0
        ;;
state-changed)
        logger -p warning "${0}: (${3}) state changed to ${4} [${1}]" >&1
        exit 0
        ;;
warning-capacity|warning-under)
        logger -p warning \
            "${0}: (${3}) capacity below warning limit [${1}]" >&1
        exit 0
        ;;
critical-capacity|critical-under)
        logger -p warning \
            "${0}: (${3}) capacity below critical limit [${1}]" >&1
        echo -n C >/dev/speaker
        exit 0
        ;;
warning-over)
        logger -p warning \
            "${0}: (${3}) capacity above warning limit [${1}]" >&1
        echo -n CD >/dev/speaker
        exit 0
        ;;
        critical-over)
        logger -p warning \
            "${0}: (${3}) capacity above critical limit [${1}]" >&1
        exit 0
        ;;
high-capacity)
        logger -p warning \
            "${0}: (${3}) capacity above high limit [${1}]" >&1
        exit 0
        ;;
maximum-capacity)
        logger -p warning \
            "${0}: (${3}) capacity above maximum limit [${1}]" >&1
        exit 0
        ;;
#
# This event is _ONLY_ received when all AC Adapters are OFF and all
# batteries on the system are in CRITICAL or LOW state.
#
# It is not recommended to remove the shutdown call.
#
low-power)
        logger -p warning "${0}: LOW POWER! SHUTTING DOWN." >&1
        /sbin/shutdown -p now "${0}: LOW POWER! SHUTTING DOWN."
        echo -n CDEF >/dev/speaker
        exit 0
        ;;
*)
        logger -p warning "${0}: unsupported event ${2} on device ${1}" >&1
        exit 1
        ;;
esac

Rrvp · Mar 13, 2021

pfr I assumed I could just add this to the /etc/powerd/scripts/sensor_battery script like so but it didn't work.

powerd running? powerd=YES in /etc/rc.conf? (it's enabled by default in /etc/defaults/rc.conf)
Does the beep work on the command line?

The script looks OK, except:

There is no beep for warning-under (10%)--only critical-under (1%) & warning-over (why this?) beep.
For the low-power event, the beep should come before shutdown is initiated.

pfr Does it need to be called from a separate script?

A separate script like /usr/local/bin/alarm.sh (with the event passed to it) would be cleaner.
And, I don't understand why you want a pathetic bleep when one can go Dive! Dive! Dive!

pfr · Mar 13, 2021

rvp powerd running? powerd=YES in /etc/rc.conf?

Yes.

rvp Does the beep work on the command line?

Yes

rvp The script looks OK, except:
There is no beep for warning-under (10%)--only critical-under (1%) & warning-over (why this?) beep.
For the low-power event, the beep should come before shutdown is initiated.

This is the default script, I only added the calls to /dev/speaker

I've changed it to look like this:

warning-capacity|warning-under)
    logger -p warning \
        "${0}: (${3}) capacity below warning limit [${1}]" >&1
    echo -n C >/dev/speaker
    exit 0
    ;;
critical-capacity|critical-under)
    logger -p warning \
        "${0}: (${3}) capacity below critical limit [${1}]" >&1
    echo -n CD >/dev/speaker
    exit 0
    ;;

&

low-power)
    logger -p warning "${0}: LOW POWER! SHUTTING DOWN." >&1
    echo -n CDEF >/dev/speaker  
    /sbin/shutdown -p now "${0}: LOW POWER! SHUTTING DOWN."
    exit 0
    ;;

I got a beep once rendomly at 4% will keep testing.

rvp A separate script like /usr/local/bin/alarm.sh (with the event passed to it) would be cleaner.
And, I don't understand why you want a pathetic bleep when one can go Dive! Dive! Dive!

How does calling a separate script keep it cleaner? Without it, it's one less script right?

And I don't need a fancy alarm, I like to use what tools are built in.

Rrvp · Mar 13, 2021

The changes now look OK.

pfr I got a beep once rendomly at 4% will keep testing.

Right. Note that warning-under and critical-under are 10% and 1% of the original design capacity. As the battery ages, and the last full capacity decreases, these percentages will creep upwards. envstat will tell you what the current values are.

pfr How does calling a separate script keep it cleaner?

Well, you can use the same line in sensor_battery:

test -x /usr/local/bin/alarm.sh && /usr/local/bin/alarm.sh ${2}

and take different actions based on the event. Then, if you want to take more actions later, you can just edit your script instead of fiddling with the system ones.

For instance, let's say you want to sound a klaxon alarm (I'm not saying you should--just hypothetically). Here, you would:

$ youtube-dl -f 140 https://www.youtube.com/watch?v=39rw7dgX1wo
$ ffmpeg -loglevel error -i Submarine\ Dive\ Alarm-39rw7dgX1wo.m4a -t 8 klaxon.wav

and, in the script, you would call:

audioplay /some/path/klaxon.wav

And, if a klaxon blaring is missed, email the user:

mail -s 'Battery critical alert' me <<\EoF
Battery is critical. Shutdown system now.
Alaaaaarm! Awooga! Awooga! Awooga!
EoF

Also, pop-up a message:

xmessage -fn lucidasans-bold-24 -bg Red -fg Ivory -center \
	$'Battery is critical.\nShutdown NOW!'

If those are missed, blink the screen:

#!/bin/sh
N=${1:-3}
i=1
cmd_off="/opt/intel_backlight/bin/intel_backlight 0"
cmd_on="/opt/intel_backlight/bin/intel_backlight 86"
while [ $i -le $N ]
do	>/dev/null $cmd_off; sleep .75
	>/dev/null $cmd_on; sleep .5
	i=$((i + 1))
done

Or, in extreme cases, fill the whole screen red:

xterm -fa 'Bitstream Vera Sans Mono:style=Bold' -fs 48 \
	-fullscreen -bg Red -fg Ivory -e '
tput blink civis
printf "Battery critical\nShutdown NOW!!!\n" | centre.awk
read x'

centre.awk:

#!/usr/bin/awk -f
{
	if (length > MAX)
		MAX = length
	L[NR] = $0
}
END {
	system("tput clear")
	cmd = "stty -f /dev/stderr size"
	cmd | getline
	close(cmd)
	if (($1 + 0 < NR) || ($2 + 0 < MAX))
		exit 1
	row = ($1 - NR) / 2
	col = ($2 - MAX) / 2
	for (i = 1; i <= NR; i++) {
		cmd = sprintf("tput cup %d %d", row++, col)
		system(cmd)
		printf("%s", L[i])
	}
}

Endless possibilities...

pfr · Mar 15, 2021

rvp envstat will tell you what the current values are.

Ok great, will check that out. Ideally I'd like a warning before I get down to 4%

rvp For instance, let's say you want to sound a klaxon alarm (I'm not saying you should--just hypothetically)

You must be a submarine guy? This is certainly very cool, and I may end up doing somehting like this next time I get bored. But for now, a simple beep will suffice.

One thing I'm trying to figure out with spkr is how to speed up the tempo of the beeps. I've read the man page but there are no examples so I don't really know what the command should look like.

Rrvp · Mar 15, 2021

pfr echo 'L32 C D E' >/dev/speaker

pfr · Mar 15, 2021

rvp
echo 'L32 C D E F C D E F C D E F' >/dev/speaker will do it.

Thanks!

pfr · Mar 15, 2021

New day, new question. This time it's an error trying to install ueberzug using pip

Unfortunately the developer of ueberzug no longer allows for issues to be opened on github, so i'm coming here to see if anyone can help.

$ pip install ueberzug 
Defaulting to user installation because normal site-packages is not writeable
Collecting ueberzug
  Using cached ueberzug-18.1.9.tar.gz (36 kB)
Requirement already satisfied: python-xlib in ./.local/lib/python3.8/site-packages (from ueberzug) (0.29)
Requirement already satisfied: pillow in ./.local/lib/python3.8/site-packages (from ueberzug) (8.1.2)
Requirement already satisfied: docopt in ./.local/lib/python3.8/site-packages (from ueberzug) (0.6.2)
Requirement already satisfied: attrs>=18.2.0 in ./.local/lib/python3.8/site-packages (from ueberzug) (20.3.0)
Requirement already satisfied: six>=1.10.0 in ./.local/lib/python3.8/site-packages (from python-xlib->ueberzug) (1.15.0)
Using legacy 'setup.py install' for ueberzug, since package 'wheel' is not installed.
Installing collected packages: ueberzug
    Running setup.py install for ueberzug ... error
    ERROR: Command errored out with exit status 1:
     command: /usr/pkg/bin/python3.8 -u -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/tmp/pip-install-772bmp51/ueberzug_b53c21eb3dcb4dedb1ca878cf7509f88/setup.py'"'"'; __file__='"'"'/tmp/pip-install-772bmp51/ueberzug_b53c21eb3dcb4dedb1ca878cf7509f88/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' install --record /tmp/pip-record-ntig073p/install-record.txt --single-version-externally-managed --user --prefix= --compile --install-headers /home/dave/.local/include/python3.8/ueberzug
         cwd: /tmp/pip-install-772bmp51/ueberzug_b53c21eb3dcb4dedb1ca878cf7509f88/
    Complete output (51 lines):
    running install
    running build
    running build_py
    creating build
    creating build/lib.netbsd-9.1_STABLE-amd64-3.8
    creating build/lib.netbsd-9.1_STABLE-amd64-3.8/ueberzug
    copying ueberzug/__init__.py -> build/lib.netbsd-9.1_STABLE-amd64-3.8/ueberzug
    copying ueberzug/__main__.py -> build/lib.netbsd-9.1_STABLE-amd64-3.8/ueberzug
    copying ueberzug/action.py -> build/lib.netbsd-9.1_STABLE-amd64-3.8/ueberzug
    copying ueberzug/batch.py -> build/lib.netbsd-9.1_STABLE-amd64-3.8/ueberzug
    copying ueberzug/conversion.py -> build/lib.netbsd-9.1_STABLE-amd64-3.8/ueberzug
    copying ueberzug/files.py -> build/lib.netbsd-9.1_STABLE-amd64-3.8/ueberzug
    copying ueberzug/geometry.py -> build/lib.netbsd-9.1_STABLE-amd64-3.8/ueberzug
    copying ueberzug/layer.py -> build/lib.netbsd-9.1_STABLE-amd64-3.8/ueberzug
    copying ueberzug/library.py -> build/lib.netbsd-9.1_STABLE-amd64-3.8/ueberzug
    copying ueberzug/loading.py -> build/lib.netbsd-9.1_STABLE-amd64-3.8/ueberzug
    copying ueberzug/parser.py -> build/lib.netbsd-9.1_STABLE-amd64-3.8/ueberzug
    copying ueberzug/pattern.py -> build/lib.netbsd-9.1_STABLE-amd64-3.8/ueberzug
    copying ueberzug/process.py -> build/lib.netbsd-9.1_STABLE-amd64-3.8/ueberzug
    copying ueberzug/query_windows.py -> build/lib.netbsd-9.1_STABLE-amd64-3.8/ueberzug
    copying ueberzug/scaling.py -> build/lib.netbsd-9.1_STABLE-amd64-3.8/ueberzug
    copying ueberzug/terminal.py -> build/lib.netbsd-9.1_STABLE-amd64-3.8/ueberzug
    copying ueberzug/thread.py -> build/lib.netbsd-9.1_STABLE-amd64-3.8/ueberzug
    copying ueberzug/tmux_util.py -> build/lib.netbsd-9.1_STABLE-amd64-3.8/ueberzug
    copying ueberzug/ui.py -> build/lib.netbsd-9.1_STABLE-amd64-3.8/ueberzug
    copying ueberzug/version.py -> build/lib.netbsd-9.1_STABLE-amd64-3.8/ueberzug
    copying ueberzug/xutil.py -> build/lib.netbsd-9.1_STABLE-amd64-3.8/ueberzug
    creating build/lib.netbsd-9.1_STABLE-amd64-3.8/ueberzug/lib
    copying ueberzug/lib/__init__.py -> build/lib.netbsd-9.1_STABLE-amd64-3.8/ueberzug/lib
    creating build/lib.netbsd-9.1_STABLE-amd64-3.8/ueberzug/lib/v0
    copying ueberzug/lib/v0/__init__.py -> build/lib.netbsd-9.1_STABLE-amd64-3.8/ueberzug/lib/v0
    running egg_info
    writing ueberzug.egg-info/PKG-INFO
    writing dependency_links to ueberzug.egg-info/dependency_links.txt
    writing entry points to ueberzug.egg-info/entry_points.txt
    writing requirements to ueberzug.egg-info/requires.txt
    writing top-level names to ueberzug.egg-info/top_level.txt
    reading manifest file 'ueberzug.egg-info/SOURCES.txt'
    reading manifest template 'MANIFEST.in'
    writing manifest file 'ueberzug.egg-info/SOURCES.txt'
    copying ueberzug/lib/lib.sh -> build/lib.netbsd-9.1_STABLE-amd64-3.8/ueberzug/lib
    running build_ext
    building 'Xshm' extension
    creating build/temp.netbsd-9.1_STABLE-amd64-3.8
    creating build/temp.netbsd-9.1_STABLE-amd64-3.8/Xshm
    gcc -pthread -Wno-unused-result -Wsign-compare -DNDEBUG -O2 -D_FORTIFY_SOURCE=2 -I/usr/include -I/usr/pkg/include -O2 -D_FORTIFY_SOURCE=2 -I/usr/include -I/usr/pkg/include -O2 -D_FORTIFY_SOURCE=2 -I/usr/include -I/usr/pkg/include -fPIC -I/usr/pkg/include/python3.8 -c Xshm/Xshm.c -o build/temp.netbsd-9.1_STABLE-amd64-3.8/Xshm/Xshm.o
    Xshm/Xshm.c:5:10: fatal error: X11/Xlib.h: No such file or directory
     #include <X11/Xlib.h>
              ^~~~~~~~~~~~
    compilation terminated.
    error: command 'gcc' failed with exit status 1
    ----------------------------------------
ERROR: Command errored out with exit status 1: /usr/pkg/bin/python3.8 -u -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/tmp/pip-install-772bmp51/ueberzug_b53c21eb3dcb4dedb1ca878cf7509f88/setup.py'"'"'; __file__='"'"'/tmp/pip-install-772bmp51/ueberzug_b53c21eb3dcb4dedb1ca878cf7509f88/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' install --record /tmp/pip-record-ntig073p/install-record.txt --single-version-externally-managed --user --prefix= --compile --install-headers /home/dave/.local/include/python3.8/ueberzug Check the logs for full command output.

It would appear that Xshm (or lack thereof) may be the issue?

EDIT: I could potentially open a new thread for this one, but I just don't to spam the forum with to many questions.

pin · Mar 16, 2021

pfr It would appear that Xshm (or lack thereof) may be the issue?

Not really, it can't find libX11 headers. Usually you need to tell the compiler where to find it.

Rrvp · Mar 16, 2021

pin it can't find libX11 headers.

Correct.

Do: export CPPFLAGS=-I/usr/X11R7/include, then do the (clean) build again. (This is probably not the official python way, but, it should work.)

pfr · Mar 18, 2021

rvp Do: export CPPFLAGS=-I/usr/X11R7/include, then do the (clean) build again. (This is probably not the official python way, but, it should work.)

That worked. Cheers!