#!/usr/bin/ksh

FILE=$HOME/lab1_err
#IFS=''
change_perm() {
   chmod -- $1 "$2"  2>>$LOG_FILE || 
               echo "Cannot change permissions: $2" >&2 
}
while true
do
   [ -w $FILE ] && LOG_FILE=$FILE || LOG_FILE=/dev/null
   echo 'Menu:
1. Print current directory name.
2. Print directory content.
3. Create directory.
4. Add write rights to the directory.
5. Remove write rights to the directory.
6. Quit.'

   echo "Enter code:"; read item || exit -1
   case $item in
      1) pwd 2>>$LOG_FILE || echo "Cannot print directory name" >&2 ;;
      2) ls 2>>$LOG_FILE || echo "Cannot print content" >&2 ;;
      3)  
         echo "Directory name:"; read item
         mkdir -- "$item" 2>>$LOG_FILE || 
                  echo "Cannot create a directory: $item." >&2 
         ;;
      4) 
         echo "Directory name:"; read item
         [ -d "$item" ] && change_perm a+w "$item" || 
                  echo "No such directory: $item" >&2 ;;         
      5) 
         echo "Directory name:"; read item
         [ -d "$item" ] && change_perm a-w "$item"  || 
                  echo "No such directory: $item" >&2 ;;
      6) exit 0 ;;
      *) echo 'Unknown code' >&2 ;;
   esac 
done