pwd
mkdir ex1
pwd
cd ex1
pwd
ls -l
echo good morning
echo good morning > gm
ls -l
echo good evening
echo good evening > ge
ls -l
echo good night > gn
ls
ls -l
cat gm
cat ge
cat gn
cat gm ge gn
rm ge
ls -l
cat gm gn > gg
ls -l
mv gg gmn
ls -l
cat gmn