tac --help

tac --version

tac filename

tac abc.txt

tac file1 file2 ...

tac abc.txt def.txt

tac -b abc.txt def.txt

tac -r abc.txt def.txt

echo "Sandy,Mandy" | tac

 

echo "Sandy,Mandy" | tac -s ,

echo "Sandy,Mandy" | tac -b -s ,