CPENT/LPT Master Preparation Tips

Cron script to send alert on low battery

Warn when battery is low

I am very lazy to look at battery status and want to be warned when the battery is low. This means that even if I am away from the laptop, I can be warned that laptop is about to poweroff due to battery low. So, what kind of alerts I can have, many -

1. zenity message box
2. email
3. sms with twillio
4. Telegram message and possibility is endless.

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LOW=35 ## This si the lowest percentage at which I want the alerts.
## Parse the acpi statue and decide if alert needs to be sent
per=$(/usr/bin/acpi -b | awk '{print $4}'|sed 's/%.*//') 

# source ~/bin/cron-scripts/sendsms.sh
if [[ $(/usr/bin/acpi |grep -c "Full\|Charging") > 0 ]]
then
    #This is when the AC is connected.
    exit 0
fi


if [[ ! -z $per && $per < $LOW ]]
then
    # sendsms "Battery is at $per%"
    export sub="Battery is at $per%"
    echo "Battery is running out : $per"|/usr/sbin/sendmail -t
    display_msg.sh "ACPI Warn" "Battery is at $per%"
    echo "ACPI Warn" "Battery is at $per%" | /home/amitag/bin/twilio-sms +919535210501
    zenity --warning --text="Battery is at $per%"
fi

Put this script somewhere and schedule in cron for every minute and enjoy.

Some good find alias.

Here are some interesting alias’s that you may want to add to your bashrc file or where-ever else you add your aliase’s. Very useful if you use find commonly.

There are four aliases defined here and have a comment explaining what it does. but these are so simple and useful that you probably dont even need the comments.

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# ff:  to find a file under the current directory
ff () { find . -name "$@" ; }
# ffs: to find a file whose name starts with a given string
ffs () { find . -name "$@"'*' ; }
# ffe: to find a file whose name ends with a given string
ffe () { find . -name '*'"$@" ; }
# very very useful function: for finding files with ignore case, just type "f <part of filename>"
# This in combination with alias for 'g' is deadly.
#
f () { find . -iname '*'"$@"'*' ; }

Hope this is useful for you.

Books menu with bash

If you have a folder full of ebooks in various formats and not necessarily one sigle format and you want to have a quick menu to browse though your collection without requiring to open a File Manager then you are going to love this script.

The scripts works by allowing you to browse to the requied folder of your choice and once you select the file, then using xdg-open to open the file with your default viewer.

Pygmentize to color code block

Podman repositories on ubuntu like distros

Recently I installed podman on ubuntu based dervative. I like podman a lot but to my distress I found that after installation, I was not able to search or run any containers. Found out that the repositories were not configured. So, if you run into such issues, then here is what you need to do. You need to create a file /etc/containers/registries.conf. And the contents of the file for just one docker hub registries would be -