Domain name validation in interactive installer

src/freedombone

   fi
 }
 
+# test a domain name to see if it's valid
+function validate_domain_name {
+  # count the number of dots in the domain name
+  dots=${TEST_DOMAIN_NAME//[^.]}
+  no_of_dots=${#dots}
+  if (( $no_of_dots > 2 )); then
+      TEST_DOMAIN_NAME="The domain $TEST_DOMAIN_NAME has too many subdomains. It should be of the type x.y.z or y.z"
+  fi
+  if (( $no_of_dots == 0 )); then
+      TEST_DOMAIN_NAME="The domain $TEST_DOMAIN_NAME has no top level domain. It should be of the type x.y.z or y.z"
+  fi
+}
+
 function save_configuration_file {
   echo "MY_USERNAME=$MY_USERNAME" > freedombone.cfg
   echo "DOMAIN_NAME=$DOMAIN_NAME" >> freedombone.cfg
           dialog --backtitle "Freedombone Configuration" \
                  --title "Wiki Configuration" \
                  --form "\nPlease enter your wiki details:" 11 55 3 \
-                 "Title:" 1 1 "My Wiki" 1 16 16 15 \
-                 "Domain:" 2 1 "" 2 16 16 15 \
+                 "Title:" 1 1 "$WIKI_TITLE" 1 16 25 40 \
+                 "Domain:" 2 1 "$WIKI_DOMAIN_NAME" 2 16 25 40 \
                  2> $data
           sel=$?
           case $sel in
           WIKI_TITLE=$(cat $data | sed -n 1p)
           WIKI_DOMAIN_NAME=$(cat $data | sed -n 2p)
           if [ $WIKI_DOMAIN_NAME ]; then
-              if [ ! $DOMAIN_NAME ]; then
-                  DOMAIN_NAME=$WIKI_DOMAIN_NAME
+              TEST_DOMAIN_NAME=$WIKI_DOMAIN_NAME
+              validate_domain_name
+              if [[ $TEST_DOMAIN_NAME != $WIKI_DOMAIN_NAME ]]; then
+                  WIKI_DOMAIN_NAME=
+                  dialog --title "Domain name validation" --msgbox "$TEST_DOMAIN_NAME" 15 50
+              else
+                  if [ ! $DOMAIN_NAME ]; then
+                      DOMAIN_NAME=$WIKI_DOMAIN_NAME
+                  fi
               fi
           fi
       done
           dialog --backtitle "Freedombone Configuration" \
                  --title "Blog Configuration" \
                  --form "\nPlease enter your blog details:" 11 55 3 \
-                 "Title:" 1 1 "My Blog" 1 16 16 15 \
-                 "Domain:" 2 1 "" 2 16 16 15 \
+                 "Title:" 1 1 "My Blog" 1 16 25 30 \
+                 "Domain:" 2 1 "" 2 16 25 30 \
                  2> $data
           sel=$?
           case $sel in
               if [[ $FULLBLOG_DOMAIN_NAME == "$WIKI_DOMAIN_NAME" ]]; then
                   FULLBLOG_DOMAIN_NAME=""
               fi
-              if [ ! $DOMAIN_NAME ]; then
-                  DOMAIN_NAME=$FULLBLOG_DOMAIN_NAME
+              TEST_DOMAIN_NAME=$FULLBLOG_DOMAIN_NAME
+              validate_domain_name
+              if [[ $TEST_DOMAIN_NAME != $FULLBLOG_DOMAIN_NAME ]]; then
+                  FULLBLOG_DOMAIN_NAME=
+                  dialog --title "Domain name validation" --msgbox "$TEST_DOMAIN_NAME" 15 50
+              else
+                  if [ ! $DOMAIN_NAME ]; then
+                      DOMAIN_NAME=$FULLBLOG_DOMAIN_NAME
+                  fi
               fi
           fi
       done
           dialog --backtitle "Freedombone Configuration" \
                  --title "Owncloud Configuration" \
                  --form "\nPlease enter your Owncloud details:" 11 55 3 \
-                 "Domain:" 1 1 "" 1 16 16 15 \
+                 "Domain:" 1 1 "" 1 16 25 30 \
                  2> $data
           sel=$?
           case $sel in
           esac
           OWNCLOUD_DOMAIN_NAME=$(cat $data | sed -n 1p)
           if [ $OWNCLOUD_DOMAIN_NAME ]; then
-              if [ ! $DOMAIN_NAME ]; then
-                  DOMAIN_NAME=$OWNCLOUD_DOMAIN_NAME
+              TEST_DOMAIN_NAME=$OWNCLOUD_DOMAIN_NAME
+              validate_domain_name
+              if [[ $TEST_DOMAIN_NAME != $OWNCLOUD_DOMAIN_NAME ]]; then
+                  OWNCLOUD_DOMAIN_NAME=
+                  dialog --title "Domain name validation" --msgbox "$TEST_DOMAIN_NAME" 15 50
+              else
+                  if [ ! $DOMAIN_NAME ]; then
+                      DOMAIN_NAME=$OWNCLOUD_DOMAIN_NAME
+                  fi
               fi
           fi
       done
           dialog --backtitle "Freedombone Configuration" \
                  --title "RedMatrix Configuration" \
                  --form "\nPlease enter your RedMatrix details:" 11 55 3 \
-                 "Domain:" 1 1 "" 1 16 16 15 \
+                 "Domain:" 1 1 "" 1 16 25 30 \
                  2> $data
           sel=$?
           case $sel in
           esac
           REDMATRIX_DOMAIN_NAME=$(cat $data | sed -n 1p)
           if [ $REDMATRIX_DOMAIN_NAME ]; then
-              if [ ! $DOMAIN_NAME ]; then
-                  DOMAIN_NAME=$REDMATRIX_DOMAIN_NAME
+              TEST_DOMAIN_NAME=$REDMATRIX_DOMAIN_NAME
+              validate_domain_name
+              if [[ $TEST_DOMAIN_NAME != $REDMATRIX_DOMAIN_NAME ]]; then
+                  REDMATRIX_DOMAIN_NAME=
+                  dialog --title "Domain name validation" --msgbox "$TEST_DOMAIN_NAME" 15 50
+              else
+                  if [ ! $DOMAIN_NAME ]; then
+                      DOMAIN_NAME=$REDMATRIX_DOMAIN_NAME
+                  fi
               fi
           fi
       done
           dialog --backtitle "Freedombone Configuration" \
                  --title "Microblog Configuration" \
                  --form "\nPlease enter your Microblog details:" 11 55 3 \
-                 "Domain:" 1 1 "" 1 16 16 15 \
+                 "Domain:" 1 1 "" 1 16 25 30 \
                  2> $data
           sel=$?
           case $sel in
               if [[ $MICROBLOG_DOMAIN_NAME == "$REDMATRIX_DOMAIN_NAME" ]]; then
                   MICROBLOG_DOMAIN_NAME=""
               fi
-              if [ ! $DOMAIN_NAME ]; then
-                  DOMAIN_NAME=$MICROBLOG_DOMAIN_NAME
+              TEST_DOMAIN_NAME=$MICROBLOG_DOMAIN_NAME
+              validate_domain_name
+              if [[ $TEST_DOMAIN_NAME != $MICROBLOG_DOMAIN_NAME ]]; then
+                  MICROBLOG_DOMAIN_NAME=
+                  dialog --title "Domain name validation" --msgbox "$TEST_DOMAIN_NAME" 15 50
+              else
+                  if [ ! $DOMAIN_NAME ]; then
+                      DOMAIN_NAME=$MICROBLOG_DOMAIN_NAME
+                  fi
               fi
           fi
       done