Improve portion of the dialog(1) API in dialog.subr responsible for

retrieving stored data (for the --menu, --calendar, --timebox, --checklist,
and --radiolist widgets).

When we (Ron McDowell and I) developed the first version of bsdconfig, it
used temporary files to store responses from dialog(1). That hasn't been
true for some very long time, so the need to always store the return status
of dialog(1) and then call some function to clean-up is long-deprecated. The
function that used to do the clean-up was f_dialog_menutag().

We really don't need f_dialog_menutag() for its originally designed purpose,
as all dialog invocations (even when in a sub-shell) do not use temporary
files anymore.

However, we do need to keep f_dialog_menutag() around because it still fills
the need of being able to abstract the procedure for fetching stored data
provided by functions that display the aforementioned widgets.

In re-designing f_dialog_menutag(), four important changes are made:

1. Rename f_dialog_menutag() to f_dialog_menutag_fetch()
2. Introduce the new first-argument of $var_to_set to reduce number of forks
3. Create a corresponding f_dialog_menutag_store() to abstract the storage
4. Offload the sanitization to a new function, f_dialog_data_sanitize()

NOTE: That last one is important. Not all functions need to store their data
for later fetching, meanwhile every invocation of dialog should be sanitized
(as we learned early-on in the i18n-effort -- underlying libraries will spit
warnings to stderr for bad values of $LANG and since dialog outputs its
responses to stderr, we need to sanitize every response of these warnings).

These changes greatly improve readbaility and also improve performance by
reducing unnecessary forking.

7 files changed, 37 insertions, 56 deletions

diff --git a/usr.sbin/bsdconfig/console/console b/usr.sbin/bsdconfig/console/console
index da71c73..630d071 100755
--- a/usr.sbin/bsdconfig/console/console
+++ b/usr.sbin/bsdconfig/console/console
@@ -70,8 +70,8 @@ dialog_menu_main()
 	                        \"\$hline\"            \
 	                        $menu_list
 
-	local dialog_menu
-	dialog_menu=$( eval $DIALOG \
+	local menu_choice
+	menu_choice=$( eval $DIALOG \
 		--title \"\$DIALOG_TITLE\"          \
 		--backtitle \"\$DIALOG_BACKTITLE\"  \
 		--hline \"\$hline\"                 \
@@ -84,8 +84,9 @@ dialog_menu_main()
 		2>&1 >&$DIALOG_TERMINAL_PASSTHRU_FD
 	)
 	local retval=$?
-	setvar DEFAULTITEM_$$ "$dialog_menu"
-	setvar DIALOG_MENU_$$ "$dialog_menu"
+	f_dialog_data_sanitize menu_choice
+	f_dialog_menutag_store "$menu_choice"
+	setvar DEFAULTITEM_$$ "$menu_choice"
 	return $retval
 }
 
@@ -115,11 +116,8 @@ f_mustberoot_init
 # Launch application main menu
 #
 while :; do
-	dialog_menu_main
-	retval=$?
-	mtag=$( f_dialog_menutag )
-
-	[ $retval -eq 0 ] || f_die
+	dialog_menu_main || f_die
+	f_dialog_menutag_fetch mtag
 
 	case "$mtag" in
 	"X $msg_exit") break ;;
diff --git a/usr.sbin/bsdconfig/console/font b/usr.sbin/bsdconfig/console/font
index 101a374..340bc6d 100755
--- a/usr.sbin/bsdconfig/console/font
+++ b/usr.sbin/bsdconfig/console/font
@@ -95,8 +95,8 @@ dialog_menu_main()
 	swiss-8x8) defaultitem="e $msg_swiss";;
 	esac
 
-	local dialog_menu
-	dialog_menu=$( eval $DIALOG \
+	local menu_choice
+	menu_choice=$( eval $DIALOG \
 		--title \"\$DIALOG_TITLE\"         \
 		--backtitle \"\$DIALOG_BACKTITLE\" \
 		--hline \"\$hline\"                \
@@ -109,7 +109,7 @@ dialog_menu_main()
 		2>&1 >&$DIALOG_TERMINAL_PASSTHRU_FD
 	)
 	local retval=$?
-	setvar DIALOG_MENU_$$ "$dialog_menu"
+	f_dialog_menutag_store -s "$menu_choice"
 	return $retval
 }
 
@@ -139,11 +139,8 @@ f_mustberoot_init
 # Launch application main menu
 #
 while :; do
-	dialog_menu_main
-	retval=$?
-	mtag=$( f_dialog_menutag )
-
-	[ $retval -eq 0 ] || f_die
+	dialog_menu_main || f_die
+	f_dialog_menutag_fetch mtag
 
 	case "$mtag" in
 	"1 $msg_none") # Use hardware default font
diff --git a/usr.sbin/bsdconfig/console/keymap b/usr.sbin/bsdconfig/console/keymap
index aa51f7d..fdbf511 100755
--- a/usr.sbin/bsdconfig/console/keymap
+++ b/usr.sbin/bsdconfig/console/keymap
@@ -193,8 +193,8 @@ dialog_menu_main()
 		) && defaultitem=" $defaultitem"
 	fi
 
-	local dialog_menu
-	dialog_menu=$( eval $DIALOG \
+	local menu_choice
+	menu_choice=$( eval $DIALOG \
 		--title \"\$DIALOG_TITLE\"         \
 		--backtitle \"\$DIALOG_BACKTITLE\" \
 		--hline \"\$hline\"                \
@@ -207,7 +207,7 @@ dialog_menu_main()
 		2>&1 >&$DIALOG_TERMINAL_PASSTHRU_FD
 	)
 	local retval=$?
-	setvar DIALOG_MENU_$$ "$dialog_menu"
+	f_dialog_menutag_store -s "$menu_choice"
 	return $retval
 }
 
@@ -237,11 +237,8 @@ f_mustberoot_init
 # Launch application main menu
 #
 while :; do
-	dialog_menu_main
-	retval=$?
-	mtag=$( f_dialog_menutag )
-
-	[ $retval -eq 0 ] || f_die
+	dialog_menu_main || f_die
+	f_dialog_menutag_fetch mtag
 
 	#
 	# Reverse the users choice into the variable name
diff --git a/usr.sbin/bsdconfig/console/repeat b/usr.sbin/bsdconfig/console/repeat
index 85822e0..a98e39f 100755
--- a/usr.sbin/bsdconfig/console/repeat
+++ b/usr.sbin/bsdconfig/console/repeat
@@ -75,8 +75,8 @@ dialog_menu_main()
 	[Nn][Oo]|'') defaultitem="$msg_default";;
 	esac
 
-	local dialog_menu
-	dialog_menu=$( eval $DIALOG \
+	local menu_choice
+	menu_choice=$( eval $DIALOG \
 		--title \"\$DIALOG_TITLE\"         \
 		--backtitle \"\$DIALOG_BACKTITLE\" \
 		--hline \"\$hline\"                \
@@ -89,7 +89,7 @@ dialog_menu_main()
 		2>&1 >&$DIALOG_TERMINAL_PASSTHRU_FD
 	)
 	local retval=$?
-	setvar DIALOG_MENU_$$ "$dialog_menu"
+	f_dialog_menutag_store -s "$menu_choice"
 	return $retval
 }
 
@@ -119,11 +119,8 @@ f_mustberoot_init
 # Launch application main menu
 #
 while :; do
-	dialog_menu_main
-	retval=$?
-	mtag=$( f_dialog_menutag )
-
-	[ $retval -eq 0 ] || f_die
+	dialog_menu_main || f_die
+	f_dialog_menutag_fetch mtag
 
 	case "$mtag" in
 	"$msg_slow") # Slow keyboard repeat rate
diff --git a/usr.sbin/bsdconfig/console/saver b/usr.sbin/bsdconfig/console/saver
index 99cb81c..f2c9cf7 100755
--- a/usr.sbin/bsdconfig/console/saver
+++ b/usr.sbin/bsdconfig/console/saver
@@ -94,8 +94,8 @@ dialog_menu_main()
 	[Nn][Oo]|'') defaultitem="d $msg_none"   ;;
 	esac
 
-	local dialog_menu
-	dialog_menu=$( eval $DIALOG \
+	local menu_choice
+	menu_choice=$( eval $DIALOG \
 		--title \"\$DIALOG_TITLE\"         \
 		--backtitle \"\$DIALOG_BACKTITLE\" \
 		--hline \"\$hline\"                \
@@ -108,7 +108,7 @@ dialog_menu_main()
 		2>&1 >&$DIALOG_TERMINAL_PASSTHRU_FD
 	)
 	local retval=$?
-	setvar DIALOG_MENU_$$ "$dialog_menu"
+	f_dialog_menutag_store -s "$menu_choice"
 	return $retval
 }
 
@@ -138,11 +138,8 @@ f_mustberoot_init
 # Launch application main menu
 #
 while :; do
-	dialog_menu_main
-	retval=$?
-	mtag=$( f_dialog_menutag )
-
-	[ $retval -eq 0 ] || f_die
+	dialog_menu_main || f_die
+	f_dialog_menutag_fetch mtag
 
 	case "$mtag" in
 	"1 $msg_blank") # Simply blank the screen
diff --git a/usr.sbin/bsdconfig/console/screenmap b/usr.sbin/bsdconfig/console/screenmap
index 7d72c48..6fc3ddd 100755
--- a/usr.sbin/bsdconfig/console/screenmap
+++ b/usr.sbin/bsdconfig/console/screenmap
@@ -79,8 +79,8 @@ dialog_menu_main()
 	koi8-u2cp866u)       defaultitem="6 $msg_koi8_u_to_ibm866u"    ;;
 	esac
 
-	local dialog_menu
-	dialog_menu=$( eval $DIALOG \
+	local menu_choice
+	menu_choice=$( eval $DIALOG \
 		--title \"\$DIALOG_TITLE\"         \
 		--backtitle \"\$DIALOG_BACKTITLE\" \
 		--hline \"\$hline\"                \
@@ -93,7 +93,7 @@ dialog_menu_main()
 		2>&1 >&$DIALOG_TERMINAL_PASSTHRU_FD
 	)
 	local retval=$?
-	setvar DIALOG_MENU_$$ "$dialog_menu"
+	f_dialog_menutag_store -s "$menu_choice"
 	return $retval
 }
 
@@ -123,11 +123,8 @@ f_mustberoot_init
 # Launch application main menu
 #
 while :; do
-	dialog_menu_main
-	retval=$?
-	mtag=$( f_dialog_menutag )
-
-	[ $retval -eq 0 ] || f_die
+	dialog_menu_main || f_die
+	f_dialog_menutag_fetch mtag
 
 	case "$mtag" in
 	"1 $msg_none") # No screenmap, don't touch font
diff --git a/usr.sbin/bsdconfig/console/ttys b/usr.sbin/bsdconfig/console/ttys
index 0fc83fa..96126ad 100755
--- a/usr.sbin/bsdconfig/console/ttys
+++ b/usr.sbin/bsdconfig/console/ttys
@@ -83,8 +83,8 @@ dialog_menu_main()
 	                        \"\$hline\"            \
 	                        $TTY_MENU_LIST
 
-	local dialog_menu
-	dialog_menu=$( eval $DIALOG \
+	local menu_choice
+	menu_choice=$( eval $DIALOG \
 		--title \"\$DIALOG_TITLE\"         \
 		--backtitle \"\$DIALOG_BACKTITLE\" \
 		--hline \"\$hline\"                \
@@ -96,7 +96,7 @@ dialog_menu_main()
 		2>&1 >&$DIALOG_TERMINAL_PASSTHRU_FD
 	)
 	local retval=$?
-	setvar DIALOG_MENU_$$ "$dialog_menu"
+	f_dialog_menutag_store -s "$menu_choice"
 	return $retval
 }
 
@@ -182,11 +182,9 @@ f_mustberoot_init
 # Launch application main menu
 #
 while :; do
-	dialog_menu_main
-	retval=$?
-	mtag=$( f_dialog_menutag )
+	dialog_menu_main || f_die
+	f_dialog_menutag_fetch mtag
 
-	[ $retval -eq 0 ] || f_die
 	[ "$mtag" = "1 $msg_none" ] && break
 
 	consterm=$( eval f_dialog_menutag2item \"\$mtag\" $TTY_MENU_LIST )