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.

6 files changed, 14 insertions, 21 deletions

diff --git a/usr.sbin/bsdconfig/networking/share/hostname.subr b/usr.sbin/bsdconfig/networking/share/hostname.subr
index 61df2b4..5fc3f5a 100644
--- a/usr.sbin/bsdconfig/networking/share/hostname.subr
+++ b/usr.sbin/bsdconfig/networking/share/hostname.subr
@@ -108,9 +108,8 @@ f_dialog_input_hostname()
 	# Loop until the user provides taint-free input.
 	#
 	while :; do
-		hostname=$( f_dialog_input "$msg" "$hostname" \
-		                           "$hline_alnum_punc_tab_enter"
-		          ) || return
+		f_dialog_input hostname "$msg" "$hostname" \
+		               "$hline_alnum_punc_tab_enter" || return
 		# Taint-check the user's input
 		f_dialog_validate_hostname "$hostname" && break
 	done
diff --git a/usr.sbin/bsdconfig/networking/share/ipaddr.subr b/usr.sbin/bsdconfig/networking/share/ipaddr.subr
index 4b39dd2..69777b2 100644
--- a/usr.sbin/bsdconfig/networking/share/ipaddr.subr
+++ b/usr.sbin/bsdconfig/networking/share/ipaddr.subr
@@ -162,9 +162,8 @@ f_dialog_input_ipaddr()
 		# - User has either pressed ESC or chosen Cancel/No
 		# - User has not made any changes to the given value
 		#
-		_input=$( f_dialog_input "$msg" "$_ipaddr" \
-		                         "$hline_num_punc_tab_enter"
-		        ) || return
+		f_dialog_input _input "$msg" "$_ipaddr" \
+		               "$hline_num_punc_tab_enter" || return
 		[ "$_ipaddr" = "$_input" ] && return $FAILURE
 
 		# Return success if NULL value was entered
diff --git a/usr.sbin/bsdconfig/networking/share/media.subr b/usr.sbin/bsdconfig/networking/share/media.subr
index 0ed7637..3c7f473 100644
--- a/usr.sbin/bsdconfig/networking/share/media.subr
+++ b/usr.sbin/bsdconfig/networking/share/media.subr
@@ -122,8 +122,8 @@ f_dialog_input_options()
 	local msg="$( printf "$msg_please_enter_mediaopts" "$interface" )"
 	local hline="$hline_alnum_punc_tab_enter"
 
-	local dialog_inputbox
-	dialog_inputbox=$( $DIALOG \
+	local _options
+	_options=$( $DIALOG \
 		--title "$DIALOG_TITLE"         \
 		--backtitle "$DIALOG_BACKTITLE" \
 		--hline "$hline"                \
@@ -133,10 +133,8 @@ f_dialog_input_options()
 		"$options"                      \
 		2>&1 >&$DIALOG_TERMINAL_PASSTHRU_FD
 	)
-
 	local retval=$?
-	setvar DIALOG_INPUTBOX_$$ "$dialog_inputbox"
-	local _options="$( f_dialog_inputstr )"
+	f_dialog_line_sanitize _options
 
 	[ $retval -eq $SUCCESS ] && options="$_options"
 
diff --git a/usr.sbin/bsdconfig/networking/share/netmask.subr b/usr.sbin/bsdconfig/networking/share/netmask.subr
index e6838e5..079b21d 100644
--- a/usr.sbin/bsdconfig/networking/share/netmask.subr
+++ b/usr.sbin/bsdconfig/networking/share/netmask.subr
@@ -110,9 +110,8 @@ f_dialog_input_netmask()
 		# - User has either pressed ESC or chosen Cancel/No
 		# - User has not made any changes to the given value
 		#
-		_input=$( f_dialog_input "$msg" "$_netmask" \
-		                         "$hline_num_punc_tab_enter"
-		        ) || return
+		f_dialog_input _input "$msg" "$_netmask" \
+		               "$hline_num_punc_tab_enter" || return
 		[ "$_netmask" = "$_input" ] && return $FAILURE
 
 		# Return success if NULL value was entered
diff --git a/usr.sbin/bsdconfig/networking/share/resolv.subr b/usr.sbin/bsdconfig/networking/share/resolv.subr
index 0793c81..59e0332 100644
--- a/usr.sbin/bsdconfig/networking/share/resolv.subr
+++ b/usr.sbin/bsdconfig/networking/share/resolv.subr
@@ -311,9 +311,8 @@ f_dialog_input_nameserver()
 	# Loop until the user provides taint-free input.
 	#
 	while :; do
-		new_ns=$( f_dialog_input "$msg" "$ns" \
-		                         "$hline_num_punc_tab_enter"
-		        ) || return
+		f_dialog_input new_ns "$msg" "$ns" \
+		               "$hline_num_punc_tab_enter" || return
 
 		# Take only the first "word" of the user's input
 		new_ns="${new_ns%%[$IFS]*}"
diff --git a/usr.sbin/bsdconfig/networking/share/routing.subr b/usr.sbin/bsdconfig/networking/share/routing.subr
index 2d8cafc..32c53f5 100644
--- a/usr.sbin/bsdconfig/networking/share/routing.subr
+++ b/usr.sbin/bsdconfig/networking/share/routing.subr
@@ -83,10 +83,9 @@ f_dialog_input_defaultrouter()
 	#
 	local retval
 	while :; do
-		defaultrouter=$( f_dialog_input \
-			"$msg_please_enter_default_router" \
-			"$defaultrouter" "$hline_num_punc_tab_enter"
-		)
+		f_dialog_input defaultrouter \
+		               "$msg_please_enter_default_router" \
+		               "$defaultrouter" "$hline_num_punc_tab_enter"
 		retval=$?
 		[ "$defaultrouter" ] || return $SUCCESS
 		[ $retval -eq $SUCCESS ] || return $retval