Linux - The Elite List

Create bootable USB using 'dd' command.

sudo dd bs=4M if=path/to/input.iso of=/dev/sd conv=fdatasync status=progress

Install .deb file in Linux.

sudo dpkg -i /path/a.deb

Display the first few words of a file in Linux.

head -c 100 filename

Display last few words of a file in Linux.

tail -c 100 filename

Append words to the end of the file in Linux.

echo 'input' >> filename

Insert text into the begining of a file in Linux.

sed -i '1s/^/abcde /' filename

Kill a linux process by its name.

kill -9 $(ps -ef | grep "name" | grep -o "[0-9]*" | head -1)

Cron job at random time

* */6 * * * sleep $[ ( $RANDOM % 60 ) + 1 ]m; /path-to-script

Less secure app issue - GMail, Geary

Follow the link -
Toggle button for 'Allow less secure apps'