11.       :

$ cat report_dir

old_dir=$(pwd)

echo "  : " $old_dir

go_home

echo "  : " $ (pwd)

$ cat go home

cd

echo "  : " $(pwd)

echo "  : " $old_dir

12.      read2   "read: -
 ,  ". ,    -
.           -
,     read2?

$ cat read2

echo -n " : "
read command
"$command"
echo ""

13.     :

$ cat quote_demo

twoliner="3TO  1.
  2."
echo "$twoliner"
echo $twoliner

)     echo   ? ,
.

)    IFS ,    -
  echo   .

 9.  II: Bourne Again Shell                                            349