Make mergemaster only take single letters for options as well as loop

asking a question again if given an invalid input instead of assuming
what the user wants.  /etc is not the place to make assumptions when
given invalid input.

Reformat some of the more convoluted code into seperate functions instead
of being inline using tabs instead of space indents.

Allow the user to view merged files they created with sdiff.

Allow the user to redisplay the diff between the installed file and
the new file again.

Time wasted waiting for review: 1 month 2 weeks

1 files changed, 167 insertions, 114 deletions

diff --git a/usr.sbin/mergemaster/mergemaster.sh b/usr.sbin/mergemaster/mergemaster.sh
index 367d538..6e8bb64 100755
--- a/usr.sbin/mergemaster/mergemaster.sh
+++ b/usr.sbin/mergemaster/mergemaster.sh
@@ -42,6 +42,151 @@ display_help () {
   echo "* The -a option causes mergemaster to run without prompting"
 }
 
+
+# Loop allowing the user to use sdiff to merge files and display the merged
+# file.
+merge_loop () {
+	case "${VERBOSE}" in
+   	'') ;;
+	*)
+        echo "   *** Type h at the sdiff prompt (%) to get usage help"
+		;;
+	esac
+	echo ''
+	MERGE_AGAIN=yes
+	while [ "${MERGE_AGAIN}" = "yes" ]; do
+		# Prime file.merged so we don't blat the owner/group id's
+		cp -p "${COMPFILE}" "${COMPFILE}.merged"
+		sdiff -o "${COMPFILE}.merged" --text --suppress-common-lines \
+			--width=${SCREEN_WIDTH:-80} "${COMPFILE#.}" "${COMPFILE}"
+		INSTALL_MERGED=V
+		while [ "${INSTALL_MERGED}" = "v" -o "${INSTALL_MERGED}" = "V" ]; do
+			echo ''
+			echo "  Use 'i' to install merged file"
+			echo "  Use 'r' to re-do the merge"
+			echo "  Use 'v' to view the merged file"
+			echo "  Default is to leave the temporary file to deal with by hand"
+			echo ''
+			read -p "    *** How should I deal with the merged file? [Leave it for later] " INSTALL_MERGED
+
+			case "${INSTALL_MERGED}" in
+			[iI])
+				mv "${COMPFILE}.merged" "${COMPFILE}"
+				echo ''
+				if mm_install "${COMPFILE}"; then
+					echo "     *** Merged version of ${COMPFILE} installed successfully"
+				else 
+					echo "     *** Problem installing ${COMPFILE}, it will remain to merge by hand later"
+				fi 
+				unset MERGE_AGAIN
+				;;
+			[rR])
+				rm "${COMPFILE}.merged"
+				;; 
+			[vV])
+				${PAGER} "${COMPFILE}.merged"
+				;;
+			'')
+				echo "   *** ${COMPFILE} will remain for your consideration"
+				unset MERGE_AGAIN
+				;;
+			*)
+				echo "invalid choice: ${INSTALL_MERGED}"
+				INSTALL_MERGED=V
+				;;
+			esac
+		done
+	done
+}
+
+# Loop showing user differences between files, allow merge, skip or install
+# options
+diff_loop () {
+
+	HANDLE_COMPFILE=v
+
+	while [ "${HANDLE_COMPFILE}" = "v" -o "${HANDLE_COMPFILE}" = "V" -o "${HANDLE_COMPFILE}" = "NOT V" ]; do
+		if [ -f "${COMPFILE#.}" -a -f "${COMPFILE}" ]; then
+			if [ "${HANDLE_COMPFILE}" = "v" -o "${HANDLE_COMPFILE}" = "V" ]; then
+				(
+					echo "  *** Displaying differences between ${COMPFILE} and installed version:"
+					echo ''
+				diff "${DIFF_FLAG}" "${COMPFILE#.}" "${COMPFILE}"
+				) | ${PAGER}
+				echo ''
+			fi
+		else
+			echo "  *** There is no installed version of ${COMPFILE}"
+			NO_INSTALLED=yes
+		fi
+	
+		echo "  Use 'd' to delete the temporary ${COMPFILE}"
+		echo "  Use 'i' to install the temporary ${COMPFILE}"
+		case "${NO_INSTALLED}" in
+		'')
+			echo "  Use 'm' to merge the old and new versions"
+			echo "  Use 'v' to view to differences between the old and new versions again"
+			;;
+		esac
+		echo ''
+		echo "  Default is to leave the temporary file to deal with by hand"
+		echo ''
+		read -p "How should I deal with this? [Leave it for later] " HANDLE_COMPFILE
+		case "${HANDLE_COMPFILE}" in
+		[dD])
+			rm "${COMPFILE}"
+			echo ''
+			echo "   *** Deleting ${COMPFILE}"
+			;;
+		[iI])
+			echo ''
+			if mm_install "${COMPFILE}"; then
+				echo "   *** ${COMPFILE} installed successfully"
+			else
+				echo "   *** Problem installing ${COMPFILE}, it will remain to merge by hand"
+			fi
+			;;
+		[mM])
+			case "${NO_INSTALLED}" in
+			'')
+				# interact with user to merge files
+				merge_loop
+				;;
+			*)
+				echo ''
+				echo "   *** There is no installed version of ${COMPFILE}"
+				echo ''
+				HANDLE_COMPFILE="NOT V"
+				;;
+			esac # End of "No installed version of file but user selected merge" test
+			;;
+		[vV])
+			continue
+			;;
+		'')
+			echo ''
+			echo "   *** ${COMPFILE} will remain for your consideration"
+			;;
+		*)
+			# invalid choice, show menu again.
+			echo "invalid choice: ${HANDLE_COMPFILE}"
+			echo ''
+			HANDLE_COMPFILE="NOT V"
+			continue
+			;;
+		esac  # End of "How to handle files that are different"
+	done	
+	echo ''
+	unset NO_INSTALLED
+	echo ''
+	case "${VERBOSE}" in
+	'') ;;
+	*)
+		sleep 3
+		;;
+	esac
+}
+
 # Set the default path for the temporary root environment
 #
 TEMPROOT='/var/tmp/temproot'
@@ -107,7 +252,7 @@ echo ''
 #
 case "${DONT_CHECK_PAGER}" in
 '')
-  if [ -n "${PAGER}" -a ! -x "${PAGER%% *}" ]; then
+  while [ "${PAGER}" != "more" -a -n "${PAGER}" -a ! -x "${PAGER%% *}" ]; do
     echo " *** Your PAGER environment variable specifies '${PAGER}', but"
     echo "     I cannot execute it. In general it is good practice to"
     echo "     specify the full path for environment variables like"
@@ -123,18 +268,23 @@ case "${DONT_CHECK_PAGER}" in
     echo ''
     read -p "What should I do? [Use 'more'] " FIXPAGER
     case "${FIXPAGER}" in
-    [eE]*)
+    [eE])
        exit 0
        ;;
-    [lL]*)
-       PAGER=/usr/local/bin/less
+    [lL])
+       if [ -x /usr/local/bin/less ]; then
+         PAGER=/usr/local/bin/less
+       fi
        ;;
-    *)
+    '')
        PAGER=more
        ;;
+    *)
+       echo ''
+       echo "invalid choice: ${FIXPAGER}"
     esac
     echo ''
-  fi
+  done
   ;;
 esac
 
@@ -179,26 +329,31 @@ case "${RERUN}" in
         echo ''
         read -p "How should I deal with this? [Use the existing ${TEMPROOT}] " DELORNOT
           case "${DELORNOT}" in
-          [dD]*)
+          [dD])
             echo ''
             echo "   *** Deleting the old ${TEMPROOT}"
             echo ''
             rm -rf "${TEMPROOT}"
             unset TEST_TEMP_ROOT
             ;;
-          [tT]*)
+          [tT])
             echo "   *** Enter new directory name for temporary root environment"
             read TEMPROOT
             ;;
-          [eE]*)
+          [eE])
             exit 0
             ;;
-          *)
+          '')
             echo ''
             echo "   *** Leaving ${TEMPROOT} intact"
             echo ''
             unset TEST_TEMP_ROOT
             ;;
+          *)
+            echo ''
+            echo "invalid choice: ${DELORNOT}"
+            echo ''
+            ;;
           esac
           ;;
       *)
@@ -500,110 +655,8 @@ for COMPFILE in `find . -type f -size +0`; do
       #
       case "${AUTO_RUN}" in
       '')
-        echo ''
-        if [ -f "${COMPFILE#.}" -a -f "${COMPFILE}" ]; then
-          echo "  *** Displaying differences between ${COMPFILE} and installed version"
-          echo ''
-          diff "${DIFF_FLAG}" "${COMPFILE#.}" "${COMPFILE}" | ${PAGER}
-          echo ''
-        else
-          echo "  *** There is no installed version of ${COMPFILE}"
-          NO_INSTALLED=yes
-        fi
-        echo "  Use 'd' to delete the temporary ${COMPFILE}"
-        echo "  Use 'i' to install the temporary ${COMPFILE}"
-        case "${NO_INSTALLED}" in
-        '')
-          echo "  Use 'm' to merge the old and new versions"
-          ;;
-        esac
-        echo ''
-        echo "  Default is to leave the temporary file to deal with by hand"
-        echo ''
-        read -p "How should I deal with this? [Leave it for later] " HANDLE_COMPFILE
-        case "${HANDLE_COMPFILE}" in
-        [dD]*)
-          rm "${COMPFILE}"
-          echo ''
-          echo "   *** Deleting ${COMPFILE}"
-          ;;
-        [iI]*)
-          echo ''
-          if mm_install "${COMPFILE}"; then
-            echo "   *** ${COMPFILE} installed successfully"
-          else
-            echo "   *** Problem installing ${COMPFILE}, it will remain to merge by hand"
-          fi
-          ;;
-        [mM]*)
-          case "${NO_INSTALLED}" in
-          '')
-            case "${VERBOSE}" in
-            '') ;;
-            *)
-              echo "   *** Type h at the sdiff prompt (%) to get usage help"
-              ;;
-            esac
-            echo ''
-            MERGE_AGAIN=yes
-            while [ "${MERGE_AGAIN}" = "yes" ]; do
-              # Prime file.merged so we don't blat the owner/group id's
-              cp -p "${COMPFILE}" "${COMPFILE}.merged"
-              sdiff -o "${COMPFILE}.merged" --text --suppress-common-lines \
-                --width=${SCREEN_WIDTH:-80} "${COMPFILE#.}" "${COMPFILE}"
-
-              echo ''
-              echo "  Use 'i' to install merged file"
-              echo "  Use 'r' to re-do the merge"
-              echo "  Default is to leave the temporary file to deal with by hand"
-              echo ''
-              read -p "    *** How should I deal with the merged file? [Leave it for later] " INSTALL_MERGED
-
-              case "${INSTALL_MERGED}" in
-              [iI]*)
-                mv "${COMPFILE}.merged" "${COMPFILE}"
-                echo ''
-                if mm_install "${COMPFILE}"; then
-                  echo "     *** Merged version of ${COMPFILE} installed successfully"
-                else 
-                  echo "     *** Problem installing ${COMPFILE}, it will remain to merge by hand later"
-                fi 
-                unset MERGE_AGAIN
-                ;;
-              [rR]*)
-                rm "${COMPFILE}.merged"
-                ;; 
-              *)
-                echo "   *** ${COMPFILE} will remain for your consideration"
-                unset MERGE_AGAIN
-              ;;
-              esac
-            done
-            ;;
-          *)
-            echo ''
-            echo "   *** There is no installed version of ${COMPFILE}"
-            echo "       to merge so it will remain to install by hand later"
-            echo ''
-            echo "   *** Press [Enter] or [Return] key to continue"
-            read ANY_KEY
-            unset ANY_KEY
-            ;;
-          esac # End of "No installed version of file but user selected merge" test
-          ;;
-        *)
-          echo ''
-          echo "   *** ${COMPFILE} will remain for your consideration"
-          ;;
-        esac  # End of "How to handle files that are different"
-        unset NO_INSTALLED
-        echo ''
-        case "${VERBOSE}" in
-        '') ;;
-        *)
-          sleep 3
-          ;;
-        esac
+        # prompt user to install/delete/merge changes
+        diff_loop
         ;;
       *)
         # If this is an auto run, make it official