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.

1 files changed, 9 insertions, 20 deletions

diff --git a/usr.sbin/bsdconfig/password/share/password.subr b/usr.sbin/bsdconfig/password/share/password.subr
index 2d407c4..ad1b2a1 100644
--- a/usr.sbin/bsdconfig/password/share/password.subr
+++ b/usr.sbin/bsdconfig/password/share/password.subr
@@ -69,10 +69,9 @@ f_dialog_input_password()
 	#
 	# Loop until the user provides taint-free/valid input
 	#
-	local retval _password1 _password2
+	local _password1 _password2
 	while :; do
-		local dialog_inputbox
-		dialog_inputbox=$( $DIALOG \
+		_password1=$( $DIALOG \
 			--title "$DIALOG_TITLE"         \
 			--backtitle "$DIALOG_BACKTITLE" \
 			--hline "$hline"                \
@@ -82,16 +81,11 @@ f_dialog_input_password()
 			--passwordbox "$msg"            \
 			$height1 $width1                \
 			2>&1 >&$DIALOG_TERMINAL_PASSTHRU_FD
-		)
+		) || return $?
+			# Return if user either pressed ESC or chose Cancel/No
+		debug= f_dialog_line_sanitize _password1
 
-		retval=$?
-		setvar DIALOG_INPUTBOX_$$ "$dialog_inputbox"
-		_password1=$( f_dialog_inputstr )
-
-		# Return if user has either pressed ESC or chosen Cancel/No
-		[ $retval -eq $SUCCESS ] || return $retval
-
-		dialog_inputbox=$( $DIALOG \
+		_password2=$( $DIALOG \
 			--title "$DIALOG_TITLE"         \
 			--backtitle "$DIALOG_BACKTITLE" \
 			--hline "$hline"                \
@@ -101,14 +95,9 @@ f_dialog_input_password()
 			--passwordbox "$rmsg"           \
 			$height2 $width2                \
 			2>&1 >&$DIALOG_TERMINAL_PASSTHRU_FD
-		)
-
-		retval=$?
-		setvar DIALOG_INPUTBOX_$$ "$dialog_inputbox"
-		_password2=$( f_dialog_inputstr )
-
-		# Return if user has either pressed ESC or chosen Cancel/No
-		[ $retval -eq $SUCCESS ] || return $retval
+		) || return $?
+			# Return if user either pressed ESC or chose Cancel/No
+		debug= f_dialog_line_sanitize _password2
 
 		# Check for NULL entry
 		if ! [ "$_password1" -o "$_password2" ]; then