Similar to r251236, improve the portion of dialog(1) API in dialog.subr

responsible for retrieving stored input (for the --inputbox and --password
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 a very long time, so the need to always execute some clean-up
function is long-deprecated. The function that used to perform these clean-
up routines for these widgets was f_dialog_inputstr().

We really don't need f_dialog_inputstr() for its originally designed purpose
as all dialog invocations no longer require temporary files.

Just as in r251236, redesign f_dialog_inputstr() in the following four ways:

1. Rename f_dialog_inputstr() to f_dialog_inputstr_fetch()
2. Introduce the new first-argument of $var_to_set to reduce forking
3. Create a corresponding f_dialog_inputstr_store() to abstract storage
4. Offload the sanitization to a new function, f_dialog_line_sanitize()

It should be noted that f_dialog_line_sanitize() -- unlike its cousin from
SVN r251236, f_dialog_data_sanitize() -- trims leading/trailing whitespace
from the user's input. This helps prevent errors and common mistakes caused
by the fact that the new cdialog implementation allows the right-arrow
cursor key to go beyond the last byte of realtime input (adding whitespace
at the end of the typed value).

While we're centralizing the sanitization, let's rewrite f_dialog_input()
while we're here to likewise reduce forking. The f_dialog_input() function
now expects the first argument of $var_to_set instead of producing results
on standard-out.

These changes greatly improve readability and also improve performance.

4 files changed, 109 insertions, 64 deletions

diff --git a/usr.sbin/bsdconfig/share/dialog.subr b/usr.sbin/bsdconfig/share/dialog.subr
index bfbe1db..2b65d31 100644
--- a/usr.sbin/bsdconfig/share/dialog.subr
+++ b/usr.sbin/bsdconfig/share/dialog.subr
@@ -144,6 +144,48 @@ f_dialog_data_sanitize()
 	done
 }
 
+# f_dialog_line_sanitize $var_to_edit ...
+#
+# When using dialog(1) or Xdialog(1) sometimes unintended warnings or errors
+# are generated from underlying libraries. For example, if $LANG is set to an
+# invalid or unknown locale, the warnings from the Xdialog(1) libraries will
+# clutter the output. This function helps by providing a centralied function
+# that removes spurious warnings from the dialog(1) (or Xdialog(1)) response.
+#
+# Simply pass the name of one or more variables that need to be sanitized.
+# After execution, the variables will hold their newly-sanitized data.
+#
+# This function, unlike f_dialog_data_sanitize(), also removes leading/trailing
+# whitespace from each line.
+#
+f_dialog_line_sanitize()
+{
+	if [ "$#" -eq 0 ]; then
+		f_dprintf "%s: called with zero arguments" \
+		          f_dialog_response_sanitize
+		return $FAILURE
+	fi
+
+	local __var_to_edit
+	for __var_to_edit in $*; do
+		# Skip warnings and trim leading/trailing whitespace
+		setvar $__var_to_edit "$( f_getvar $__var_to_edit | awk '
+			BEGIN { data = 0 }
+			{
+				if ( ! data )
+				{
+					if ( $0 ~ /^$/ ) next
+					if ( $0 ~ /^Gdk-WARNING \*\*:/ ) next
+					data = 1
+				}
+				sub(/^[[:space:]]*/, "")
+				sub(/[[:space:]]*$/, "")
+				print
+			}
+		' )"
+	done
+}
+
 ############################################################ TITLE FUNCTIONS
 
 # f_dialog_title [$new_title]
@@ -1588,33 +1630,45 @@ f_dialog_noyes()
 
 ############################################################ INPUT FUNCTIONS
 
-# f_dialog_inputstr
+# f_dialog_inputstr_store [-s] $text
+#
+# Store some text from a dialog(1) inputbox to be retrieved later by
+# f_dialog_inputstr_fetch(). If the first argument is `-s', the text is
+# sanitized before being stored.
+#
+f_dialog_inputstr_store()
+{
+	local sanitize=
+	[ "$1" = "-s" ] && sanitize=1 && shift 1 # -s
+	local text="$1"
+
+	# Sanitize the line before storing it if desired
+	[ "$sanitize" ] && f_dialog_line_sanitize text
+
+	setvar DIALOG_INPUTBOX_$$ "$text"
+}
+
+# f_dialog_inputstr_fetch [$var_to_set]
 #
 # Obtain the inputstr entered by the user from the most recently displayed
-# dialog(1) inputbox and clean up any temporary files/variables.
+# dialog(1) inputbox (previously stored with f_dialog_inputstr_store() above).
+# If $var_to_set is NULL or missing, output is printed to stdout (which is less
+# recommended due to performance degradation; in a loop for example).
 #
-f_dialog_inputstr()
+f_dialog_inputstr_fetch()
 {
-	# Skip warnings and trim leading/trailing whitespace from user input
-	eval echo \"\$DIALOG_INPUTBOX_$$\" | awk '
-		BEGIN { found = 0 }
-		{
-			if ( ! found )
-			{
-				if ( $0 ~ /^$/ ) next
-				if ( $0 ~ /^Gdk-WARNING \*\*:/ ) next
-				found = 1
-			}
-			sub(/^[[:space:]]*/, "")
-			sub(/[[:space:]]*$/, "")
-			print
-		}
-	'
+	local __var_to_set="$1" __cp
+
+	debug= f_getvar DIALOG_INPUTBOX_$$ "${__var_to_set:-__cp}" # get data
 	setvar DIALOG_INPUTBOX_$$ "" # scrub memory in case data was sensitive
+
+	# Return the line on standard-out if desired
+	[ "$__var_to_set" ] || echo "$__cp"
+
 	return $SUCCESS
 }
 
-# f_dialog_input $prompt [$init [$hline]]
+# f_dialog_input $var_to_set $prompt [$init [$hline]]
 #
 # Prompt the user with a dialog(1) inputbox to enter some value. The inputbox
 # remains until the the user presses ENTER or ESC, or otherwise ends the
@@ -1629,34 +1683,38 @@ f_dialog_inputstr()
 #
 f_dialog_input()
 {
-	local prompt="$1" init="$2" hline="$3"
-	local height width
-	f_dialog_inputbox_size height width \
+	local __var_to_set="$1" __prompt="$2" __init="$3" __hline="$4"
+
+	# NOTE: Function name appended to prevent __var_{height,width} values
+	#       from becoming local (and thus preventing setvar from working).
+	local __height_input __width_input
+	f_dialog_inputbox_size __height_input __width_input \
 		"$DIALOG_TITLE" "$DIALOG_BACKTITLE" \
-		"$prompt" "$init" "$hline"
+		"$__prompt" "$__init" "$__hline"
 
-	local opterm="--"
-	[ "$USE_XDIALOG" ] && opterm=
+	local __opterm="--"
+	[ "$USE_XDIALOG" ] && __opterm=
 
-	local dialog_input
-	dialog_input=$(
+	local __dialog_input
+	__dialog_input=$(
 		$DIALOG \
 			--title "$DIALOG_TITLE"         \
 			--backtitle "$DIALOG_BACKTITLE" \
-			--hline "$hline"                \
+			--hline "$__hline"              \
 			--ok-label "$msg_ok"            \
 			--cancel-label "$msg_cancel"    \
-			--inputbox "$prompt"            \
-			$height $width                  \
-			$opterm "$init"                 \
+			--inputbox "$__prompt"          \
+			$__height_input $__width_input  \
+			$__opterm "$__init"             \
 			2>&1 >&$DIALOG_TERMINAL_PASSTHRU_FD
 	)
-	local retval=$?
+	local __retval=$?
 
-	setvar DIALOG_INPUTBOX_$$ "$dialog_input"
-	f_dialog_inputstr
+	# Remove warnings and leading/trailing whitespace from user input
+	f_dialog_line_sanitize __dialog_input
 
-	return $retval
+	setvar "$__var_to_set" "$__dialog_input"
+	return $__retval
 }
 
 ############################################################ MENU FUNCTIONS
diff --git a/usr.sbin/bsdconfig/share/media/tcpip.subr b/usr.sbin/bsdconfig/share/media/tcpip.subr
index f1b4ac7..b7b7b7e 100644
--- a/usr.sbin/bsdconfig/share/media/tcpip.subr
+++ b/usr.sbin/bsdconfig/share/media/tcpip.subr
@@ -1422,29 +1422,23 @@ f_device_dialog_tcp()
 						"$_netmask" \
 						&& break ;;
 				"$msg_host_name_including_domain:")
-					cp=$( f_dialog_input "$cp" \
-					                     "$_hostname"
-					    ) && _hostname="$cp" ;;
+					f_dialog_input cp "$cp" "$_hostname" \
+						&& _hostname="$cp" ;;
 				"$msg_ipv4_gateway:")
-					cp=$( f_dialog_input "$cp" \
-					                     "$_gateway"
-					    ) && _gateway="$cp" ;;
+					f_dialog_input cp "$cp" "$_gateway" \
+						&& _gateway="$cp" ;;
 				"$msg_name_server:")
-					cp=$( f_dialog_input "$cp" \
-					                     "$_nameserver"
-					    ) && _nameserver="$cp" ;;
+					f_dialog_input cp "$cp" "$_nameserver" \
+						&& _nameserver="$cp" ;;
 				"$msg_ipv4_address:")
-					cp=$( f_dialog_input "$cp" \
-					                     "$_ipaddr"
-					    ) && _ipaddr="$cp" ;;
+					f_dialog_input cp "$cp" "$_ipaddr" \
+						&& _ipaddr="$cp" ;;
 				"$msg_netmask:")
-					cp=$( f_dialog_input "$cp" \
-					                     "$_netmask"
-					    ) && _netmask="$cp" ;;
+					f_dialog_input cp "$cp" "$_netmask" \
+						&& _netmask="$cp" ;;
 				"$msg_extra_options_to_ifconfig")
-					cp=$( f_dialog_input "$cp" \
-					                     "$_extras"
-					    ) && _extras="$cp" ;;
+					f_dialog_input cp "$cp" "$_extras" \
+						&& _extras="$cp" ;;
 				esac
 			done
 
diff --git a/usr.sbin/bsdconfig/share/mustberoot.subr b/usr.sbin/bsdconfig/share/mustberoot.subr
index 3f23e11..bf8dd67 100644
--- a/usr.sbin/bsdconfig/share/mustberoot.subr
+++ b/usr.sbin/bsdconfig/share/mustberoot.subr
@@ -177,8 +177,7 @@ f_become_root_via_sudo()
 				[ $retval -eq 255 ] &&
 					f_die $retval "$password"
 			else
-				local dialog_inputbox
-				dialog_inputbox=$( $DIALOG \
+				password=$( $DIALOG \
 					--title "$DIALOG_TITLE"         \
 					--backtitle "$DIALOG_BACKTITLE" \
 					--hline "$hline"                \
@@ -188,14 +187,9 @@ f_become_root_via_sudo()
 					--passwordbox "$msg"            \
 					$height $width                  \
 					2>&1 >&$DIALOG_TERMINAL_PASSTHRU_FD
-				)
-				retval=$?
-				setvar DIALOG_INPUTBOX_$$ "$dialog_inputbox"
-				password=$( f_dialog_inputstr )
+				) || exit $?
 			fi
-
-			# Exit if the user cancelled.
-			[ $retval -eq $SUCCESS ] || exit $retval
+			debug= f_dialog_line_sanitize password
 
 			#
 			# Validate sudo(8) credentials
diff --git a/usr.sbin/bsdconfig/share/variable.subr b/usr.sbin/bsdconfig/share/variable.subr
index f51ebd6..079c564 100644
--- a/usr.sbin/bsdconfig/share/variable.subr
+++ b/usr.sbin/bsdconfig/share/variable.subr
@@ -93,8 +93,7 @@ f_variable_get_value()
 
 	if ! { f_getvar $var cp && ! f_interactive; }; then
 		shift 1 # var
-		cp=$( f_dialog_input "$( printf "$@" )" "$cp" ) &&
-			setvar $var "$cp"
+		f_dialog_input cp "$( printf "$@" )" "$cp" && setvar $var "$cp"
 	fi
 
 	return $SUCCESS