syslog in realtime tail -f /var/log/syslog
current dir pwd
monitor CPU usage, processes and RAM top
nicer monitor CPU usage, processes and RAM (needs package) htop
memory usage free -m
disk usage df -h
files & directories size du -h --max-depth=1 $PATH
repeat last command !!
top 10 commands used history | awk 'BEGIN {FS="[ \t]+|\\|"} {print $3}' | sort | uniq -c | sort -nr | head
see aliases alias
link nginx config ln -s /etc/nginx/sites-available/example.com /etc/nginx/sites-enabled/example.com