What will be the effect of the following commands?

who | grep 'mary'
who | grep '^mary'
grep '[Uu]nix' ch?/*
ls -l | sort -k4n
sed '/^$/d' text > text.out
sed 's/\([Uu]nix\)/\1(TM)/g' text > text.out
date | cut -c12-16

who | grep 'mary'
Show any who output lines that have the pattern mary

who | grep '^mary'
Show any who output lines that begin with the pattern mary

grep '[Uu]nix' ch?/*
Show lines that contain the pattern Unix or unix in all files within any directory that matches the pattern ch? (that is, ch followed by a single character)

ls -l | sort -k4n
Sort the output of ls -l numerically, starting with the fourth field of each output line

sed '/^$/d' text > text.out
Save in the file text.out the contents of the file text with the exception of any lines that contain no characters at all (e.g., are blank)

sed 's/\([Uu]nix\)/\1(TM)/g' text > text.out
Convert any occurrence of Unix or unix to append (TM) immediately after the pattern on every line of the file text, saving the output in text.out

date | cut -c12-16
Show the 12th-16th characters only of the output of the date command