cat /etc/group | cut -d ':' -f 3 | grep -E ^1[0-9]{1}[0-9]{1}$
ls -l | cut -f 2 -d '.' | grep -v ' ' | sort | uniq
last -500 | grep 'mw' | wc -l
ls -a | tr '\n' ' '
cat test.txt | head -n 5 | wc -c
ls -la | grep '^d'
ls -l /etc | tail -n +2 | grep -E '^.{7}r' | wc -l
ls -l /etc | tail -n +2 | cut -c 2-10
ls -l /etc | tail -n +2 | cut -c 5-7 | sort | uniq -c