print('hello world')

• a = all
• g = group
• o = other
• u = user (owner)

chmod {owner} - {group} - {other} filename 

use “find . -type d …” for directorys): find . -type f -not \( -name “file1.txt” -o -name “file2.lol” -o -name “file3.\*” \) -print0 | xargs -0 chown [username]

grep -rwl "search-string" /path/to/serch/dir

sudo fdisk -l
sudo mount -t vfat /dev/... 

$ ejabberdctl remove_mam_for_user_with_peer maxmustermann your.address admin@somepi.ddns.net

$ sudo df -h

$ tar -czvf name-of-archive.tar.gz /path/to/directory-or-file

$ tar -xzvf archive.tar.gz -C /path/to/extract

• x extract
• v verbos
• f files
• c compress
• z use gzip compression
• -C output path

MYSQL > ALTER TABLE [YOUR_TABLE] auto_increment = 0;

$ sudo mysql -u root -p [DATABASE] < [DUMP_FILE].sql

$ sudo mysql -u root -p -e "SELECT @@datadir;"

MYSQL > SELECT User, Host, Password FROM mysql.user;