Help finetuning i3status in Qubes dom0

[One7two99]

Hello,

after switching to i3vm in Qubes 3.2 as primary window manager I'm working on tweaking it to my needs.

I've learned that Qubes is adding a small script to generate the status bar in i3:

/usr/bin/qubes-i3status

I'd like to add the total consumed RAM in the status bar, but my scripting is not good enough to make it work, can someone give me a hint?

My current approach:

1) get the used RAM for each AppVM from running 'xl list' in dom0

[USER@dom0 ~]$ xl list

Name                                        ID   Mem VCPUs State Time(s)

dom0                                         0  4061     4     r-----     902.7

sys-net                                      1   297     2     -b----      61.1

sys-firewall                                 2  1424     2     -b----      74.3

sys-usb                                      3  1023     2     -b----      54.3

win7                                         4  4095     2     -b----     298.9

win7-dm                                      5    44     1     -b----      92.2

untrusted                                    6  3999     2     -b----     492.9

2) Extracted only the column which includes the RAM with

[USER@dom0 ~]$ xl list | awk '{print $3}'

Mem

4061

297

1424

1023

4095

44

3999

**************

QUESTION: How can I remove the first line?

**************

3) If I get rid of the first line, I could add everything up.

Looking here:

https://unix.stackexchange.com/questions/320217/how-to-calculate-the-the-value-of-each-line-with-awk-command

the command to do so would be:

[USER@dom0 ~]$ xl list | awk '{print $3}' | paste -s -d+ -

which will create:

4061+297+1424+1023+4095+44+3999

4) passing this to bc should give me the total RAM:

[USER@dom0 ~]$ xl list | awk '{print $3}' | paste -s -d+ - | bc

If someone is interested in additional tweaks to i3status:

I've added some changes to this file to format date and time and more important to get better battery metrics as I like to keep an eye on the current discharge rate to learn how system load is impacting battery runtime.

This is also usefull to learn how optimizations like tlp will influence battery runtime etc.

[...]

status_bat() {

    local my_bat=/sys/class/power_supply/BAT0

    local bat_rate=$(bc <<< "scale=1;`cat $my_bat/current_now`*`cat $my_bat/voltage_now`/10^12")"W"

    local bat=$((100*`cat $my_bat/charge_now`/`cat $my_bat/charge_full_design`))

    local ac=''

    local color=''

    if [[ $(cat /sys/class/power_supply/AC/online) == '1' ]]; then

        ac=' AC'

    elif ((bat < 25)); then

        color='#ff0000' # red

    elif ((bat < 50)); then

       color='#ff6600' #was #ffff00 = yellow before

    fi

    json bat "Bat: $bat_rate $bat%$ac" "$color"

}

[799]

[Ilpo Järvinen]

On Tue, 3 Oct 2017, 'One7two99' via qubes-users wrote:

> Hello,
>
> [ ...snip...]

>
> 2) Extracted only the column which includes the RAM with
> [USER@dom0 ~]$ xl list | awk '{print $3}'
> Mem
> 4061
> 297
> 1424
> 1023
> 4095
> 44
> 3999
> **************
> QUESTION: How can I remove the first line?
> **************

| tail -n +2


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i.