need help with basic script

pfr

So I'm atempting to write a script to output information to a terminal and use it as a bar. The inspiration comes from barsh.

So far this is what I've come up with:

#!/bin/sh -e

trap 'printf \\033[?25h' EXIT INT
printf '\033[?25l'

cpu() {
	cpu="$(grep -o "^[^ ]*" /proc/loadavg)"
}

memory() {
	memory="$(free -h | sed -n "2s/\([^ ]* *\)\{2\}\([^ ]*\).*/\2/p")"
}

disk() {
	disk="$(df -h | awk 'NR==2{print $4}')"
}

datetime() {
	datetime="$(date "+%a %d %b | %I:%M")"
}

bat() {
	read -r bat_status </sys/class/power_supply/BAT1/status
	read -r bat_capacity </sys/class/power_supply/BAT1/capacity
	bat_capacity=$(( (bat_capacity * 100) / 80 ))	# set battery full at %80
	bat="$bat_status $bat_capacity%"
}

vol() {
	ID="@DEFAULT_AUDIO_SINK@"
        get_mute="$(wpctl get-volume $ID | awk '{print $3}')"
        get_vol="$(wpctl get-volume $ID | awk '{print $2}' | sed s/0.//)"
        vol="$get_mute$get_vol%"
}

display() {
	echo "[Ram $memory] [CPU $cpu] [Disk $disk] [$bat] [Vol $vol] [$datetime]"
}

while printf '\033[K"$display"\r'; do
	sleep 1 #&
#	wait && {
#		[ $((sec % 5)) -eq 0 ] && memory
#		[ $((sec % 5)) -eq 0 ] && cpu
#		[ $((sec % 5)) -eq 0 ] && disk
#		[ $((sec % 1)) -eq 0 ] && bat
#		[ $((sec % 1)) -eq 0 ] && vol
#		[ $((sec % 60)) -eq 0 ] && datetime
#		[ $((sec % 1)) -eq 0 ] && display
#		sec=$((sec + 1))
#	}
done

The commented out section at the end is supposed to allow for individual variable polling/refresh rate. But fist I'm trying to get the output to work at all.

When I run this script. I dont get the desired output, I get a terminal that says "$display".

Any sh guru's around here than can help me with this?

rvp

pfr

#!/bin/sh -e

cpu() {
	read cpu junk < /proc/loadavg
}
memory() {
	memory=$(free -h --si | awk '$1 == "Mem:" { print $3 }')
}
disk() {
	disk=$(df -H | awk '$NF == "/" { print $4 }')
}
datetime() {
	datetime=$(date '+%a %d %b | %I:%M')
}
bat() {
	read bat_status < /sys/class/power_supply/BAT0/status
	read bat_capacity < /sys/class/power_supply/BAT0/capacity
	bat_capacity=$(( (bat_capacity * 100) / 80 ))	# set battery full at %80
	bat="$bat_status $bat_capacity%"
}
vol() {
	read get_mute get_vol <<EoF
$(wpctl get-volume @DEFAULT_AUDIO_SINK@ | awk '{ print $3, $2*100"%" }')
EoF
	vol="${get_mute:-$get_vol%}"
}
display() {
	display="[RAM $memory] [CPU $cpu] [Disk $disk] [$bat] [Vol $vol] [$datetime]"
}
getcols() {
	set -- $(stty -F/dev/tty size)
	echo ${2:-80}
}

# el=$(tput el)
trap 'tput cnorm' EXIT HUP INT QUIT TERM
tput civis

# while printf '%s%s\r' "$display" "$el"; do
while printf '%*s\r' $(getcols) "$display"; do
	sleep 1 &
	wait && {
		[ $((sec % 5)) -eq 0 ]  && memory
		[ $((sec % 5)) -eq 0 ]  && cpu
		[ $((sec % 5)) -eq 0 ]  && disk
		[ $((sec % 1)) -eq 0 ]  && bat
		[ $((sec % 1)) -eq 0 ]  && vol
		[ $((sec % 60)) -eq 0 ] && datetime
		[ $((sec % 1)) -eq 0 ]  && display
		sec=$((sec + 1))
	} || break
done

kc9udx

I'm not a guru. But see if this is more like what you want to do:

#!/bin/sh -e

cpu() {
cpu="???"
}

memory() {
	memory=`vmstat | awk 'NR==3{print $4}'`
}

disk() {
	disk="$(df -h | awk 'NR==2{print $4}')"
}

datetime() {
	datetime="$(date "+%a %d %b | %I:%M")"
}

bat() {
        bat=`envstat | awk 'NR==4{print $3}'`
}

vol() {
vol="???"
}

display() {
	printf '[Ram '"$memory"'] [CPU '"$cpu"'] [Disk '"$disk"'] [Bat '"$bat"'] [Vol '"$vol"'] ['"$datetime"']\r'
}

while true; do
	sleep 1
	memory
	cpu
	disk
	bat
	vol
	datetime
	display
done

Unfortunately, I have no idea where to get CPU and Volume at the moment.

pfr

rvp Thanks!

Now this might be controversal, but what if I wanted to use this on a Linux system which doesn't have the tput command?

rvp

pfr If you have clear, you should have tput. Both are part of the ncurses package.

@rvp, I think he is using busybox instead of core-utils ; )

rvp

pin Yeah... busybox does provide clear. Still, I think a ncurses package would almost always get installed as a dep. of any sort of visual editor (and, even if it isn't because libncurses is split off on its own, that package should be pretty small). I'm sure our chum hasn't mastered ed yet... but, I could be wrong!

pfr

Looks like ncurses was not installed. And no, I definately have not mastered ed although I did uses it sucessfully to rescue my 9front system one time 😆

I have vim installed so your guess is as good as mine. Anywho.. here is the result...

How can I get rid of the double quotes on eaither side of the output? Secondly, How can I justify the output to the right of the terminal instead of the left?

Also, @rvp can you tell me, does busybox provide any alternitive to fc?

rvp

pfr Looks like ncurses was not installed.

Yeah, may not be if busybox provides most of the standard utils. It's installed on Ubuntu because of clear:

$ apt list --installed | fgrep ncurses

WARNING: apt does not have a stable CLI interface. Use with caution in scripts.

libncurses-dev/mantic,now 6.4+20230625-2 amd64 [installed]
libncurses6/mantic,now 6.4+20230625-2 amd64 [installed,automatic]
libncursesw6/mantic,now 6.4+20230625-2 amd64 [installed,automatic]
ncurses-base/mantic,now 6.4+20230625-2 all [installed]
ncurses-bin/mantic,now 6.4+20230625-2 amd64 [installed]
ncurses-doc/mantic,now 6.4+20230625-2 all [installed]
$

pfr I have vim installed so your guess is as good as mine

To my surprise, vim doesn't need libncurses, only libtinfo (and, ldd $(which vim) confirms):

$ apt-cache depends vim
vim
  Depends: vim-common
  Depends: vim-runtime
  Depends: libacl1
  Depends: libc6
  Depends: libgpm2
  Depends: libpython3.11
  Depends: libselinux1
  Depends: libsodium23
  Depends: libtinfo6
  Suggests: <ctags>
    exuberant-ctags
    universal-ctags
  Suggests: vim-doc
  Suggests: vim-scripts
$

pfr How can I get rid of the double quotes on eaither side of the output? Secondly, How can I justify the output to the right of the terminal instead of the left?

Done, above.

pfr Also, @rvp can you tell me, does busybox provide any alternitive to fc?

Doesn't look like it... write one (shouldn't be hard if you can rescue a Plan 9 using just ed)

pfr

rvp Doesn't look like it... write one (shouldn't be hard if you can rescue a Plan 9 using just ed)

I'm having trouble finding the fc source code

rvp

pfr I'm having trouble finding the fc source code

You can modify the dash implementation.

pfr I don't understand why the volume percentage is no longer shown?:

Because state now has a non-empty value in either case (muted/not-muted). Change:
vol="${state:-$get_vol}" => vol="$state $get_vol"

pfr I'm wanting to configure the 5 different battery icons to load at their respective percent amount.

Try something like:

#!/bin/sh

case $((${bat_capacity:-0} / 20)) in
0)	c='\U0001F62D' ;;	# 0 - 19
1)	c='\U0001F61F' ;;	# 20 - 39
2)	c='\U0001F610' ;;	# 40 - 59
3)	c='\U0001F60C' ;;	# 60 - 79
4|5)	c='\U0001F601' ;;	# 80 - 100
*)	c='?' ;;		# ???
esac

LANG=C.UTF-8 /usr/bin/printf "$c\n"

pfr Also, how can I convert the cpu output to a percentage?

You'll have to read /proc/stat instead of /proc/loadavg. See proc(5) for more info.

pfr

I'm keen to make this cooler, even though I've sort of abandoned the idea of a "terminal as a bar" idea..

I'm now trying to add icons, because icons are cool.

bat() {
    read bat_status < /sys/class/power_supply/BAT1/status
    read bat_capacity < /sys/class/power_supply/BAT1/capacity
    bat_capacity=$(( (bat_capacity * 100) / 80 ))   # set battery full at %80
    if [ $bat_status = "Charging" ]
    then bat_state=""
    else bat_state=""
    fi
    bat="$bat_state $bat_capacity%"
}
vol() {
    read get_mute get_vol <<EoF
    $(wpctl get-volume @DEFAULT_AUDIO_SINK@ | awk '{ print $3, $2*100"%" }')
EoF
    if [ $get_mute = "[MUTED]" ]
    then state=""
    else state=" "
    fi
    vol="${state:-$get_vol}"
}

I don't understand why the volume percentage is no longer shown?:

While I still intend to tweak this script, I will likely use something like sandbar (the above script work fine with icons when using sandbar)

So, fixing the above barsh is one thing. Moving onto sandbar. Here is my working script:

#!/bin/sh

cpu() {
    read cpu junk < /proc/loadavg
}

memory() {
    memory=$(free -h --si | awk '$1 == "Mem:" { print $3 }')
}

disk() {
    disk=$(df -H | awk '$NF == "/" { print $4 }')
}

datetime() {
	datetime="  $(date "+%a %d %b, %I:%M %p")"
}

bat() {
	read -r bat_status </sys/class/power_supply/BAT1/status
	read -r bat_capacity </sys/class/power_supply/BAT1/capacity
	bat_capacity=$(( (bat_capacity * 100) / 80 ))	# set battery full at %80

    if [ $bat_status = "Charging" ]
    then state=""
    else state=""
    fi

#"icons": [
#             "", # battery-empty
#             "", # battery-quarter
#             "", # battery-half
#             "", # battery-three-quarters
#             ""  # battery-full
#]

    bat="$state $bat_capacity%"

}

vol() {
	ID="@DEFAULT_AUDIO_SINK@"
    get_mute="$(wpctl get-volume $ID | awk '{print $3}')"
    get_vol="$(wpctl get-volume $ID | awk '{print $2*100"%"}')"

    if [ $get_mute = "[MUTED]" ]
    then state=""
    else state=" "
    fi

    vol="$state $get_vol"
}

display() {
	echo "all status C$cpu | $memory | $disk | $bat | $vol | $datetime" >"$FIFO"
}

printf "%s" "$$" > "$XDG_RUNTIME_DIR/status_pid"
FIFO="$XDG_RUNTIME_DIR/sandbar"
[ -e "$FIFO" ] || mkfifo "$FIFO"
sec=0

while true; do
	sleep 1 &
	wait && {
		[ $((sec % 15)) -eq 0 ] && memory
		[ $((sec % 15)) -eq 0 ] && cpu
		[ $((sec % 15)) -eq 0 ] && disk
		[ $((sec % 5)) -eq 0 ] && bat
		[ $((sec % 5)) -eq 0 ] && vol
		[ $((sec % 15)) -eq 0 ] && datetime
		[ $((sec % 5)) -eq 0 ] && display

		sec=$((sec + 1))
	}
done

I'm wanting to configure the 5 different battery icons to load at their respective percent amount. (I'd also prefer to use vertical battery icons if anyone can help me find them)

Here is what it looks like at the moment:

Also, how can I convert the cpu output to a percentage?

pfr

rvp You can modify the dash implementation.

Maybe there's a simpler way...

This seems to do the trick:

please() {
    doas "$(awk '{prevlast =last; last = $0} END {if (NR >= 2) print prevlast}' < ~/.ash_history)"
}

rvp

pfr Also:

tail -n2 /some/file | head -n1

or, using the versatile sed.

pfr

rvp I thought I was clever for a moment there.. 😆
Thank you, the tail method works just fine, so does sed. In your opinion, between tail and sed, what is the "correct" tool for this job? I'm only curious because unix sysadmins always tend to have opinions on such things and I'd like to know yours.

Also, while we're at it, how can I get a similar function withour fc?
on NetBSD:

alias h='fc -l -n -r 1 | sed -Ee "s/^[[:blank:]]+//" | nuniq | fzf | tr -d \\n | xclip -selection c'

on Linux:

alias h="fc -l -n -r 1 | uniq | fzf | tr -d '\n' | xclip -selection c"

I thought it should be possible just using uniq like so

uniq -u ~/.ash_history | fzf | wl-copy

or even cat:

cat ~/.ash_history | uniq -u | fzf | wl-copy

But for some reason uniq -u doesn't do what it's supposed to do here and only show the unique lines (it still shows every duplicate line in the file).

rvp

pfr In your opinion, between tail and sed, what is the "correct" tool for this job?

Well, the sed invocation is a bit cryptic, isn't it,... and it'll be slightly slower if the history file is very large (thousands of lines) because there sed reads and processes every line. The tail version will be quicker in such cases. Otherwise, it's your choice.

pfr I'm only curious because unix sysadmins always tend to have opinions on such things and I'd like to know yours.

I've never been a sysadmin, so, see prev... 😃

pfr But for some reason uniq -u doesn't do what it's supposed to do here and only show the unique lines (it still shows every duplicate line in the file).

uniq only handles adjacent duplicate lines, so either a) sort -u the file, or b) use my nuniq.sh if you want to preserve the line-order.