Introduce a function ask_yn() to use when asking 'yes or no'

questions.

ask_yn() always returns a 'y' or 'n' in $resp, vastly simplifying the
logic used to check the user response.

ask_yn() insists on the user responding with a 'y', 'n', 'yes', or
'no'. Case is ignored.

Previously almost any input was accepted as either a yes or a no
depending on the question. ask_yn() reduces the chance of user error,
e.g.  by answering the next question (default route) instead of the
posed one (Use DNS server now?).

All 'yes or no' questions now use ask_yn(). All questions show the
full default answer, i.e. 'yes' or 'no' rather than 'y' or 'n'.

Some minor logic cleanups of the usual sort, but no changes to logic
flow or questions bar minor verbiage adjustment.

Inspired by a Bob Beck install nit.

1 files changed, 62 insertions, 64 deletions

diff --git a/distrib/miniroot/install.sub b/distrib/miniroot/install.sub
index 9763d879c1b..8d3c5a09304 100644
--- a/distrib/miniroot/install.sub
+++ b/distrib/miniroot/install.sub
@@ -1,4 +1,4 @@
-#	$OpenBSD: install.sub,v 1.320 2003/08/23 22:22:02 krw Exp $
+#	$OpenBSD: install.sub,v 1.321 2003/09/22 01:31:39 krw Exp $
 #	$NetBSD: install.sub,v 1.5.2.8 1996/09/02 23:25:02 pk Exp $
 #
 # Copyright (c) 1997-2003 Todd Miller, Theo de Raadt, Ken Westerback
@@ -66,7 +66,7 @@
 # The following functions must be provided:
 #	md_congrats()		  - display friendly message
 #	md_installboot()	  - install boot-blocks on disk
-#	md_prep_disklabel()	  - label the root disk
+#	md_prep_disklabel()	  - put an OpenBSD disklabel on the disk
 #	md_set_term()		  - set up terminal
 #
 # The following variables can be provided if required:
@@ -80,7 +80,7 @@
 . install.md
 
 set_term() {
-	[ "$TERM" ] && return
+	[[ -n $TERM ]] && return
 	ask "Terminal type?" ${MDTERM:-vt220}
 	TERM=$resp
 	export TERM
@@ -89,6 +89,8 @@ set_term() {
 }
 
 welcome() {
+	local _q
+
 	cat << __EOT
 
 Welcome to the $OBSD $MODE program.
@@ -119,7 +121,7 @@ NOTE: once your system has been upgraded, you must manually merge any changes
 to files in the 'etc' set into the files already on your system.
 
 __EOT
-		ask "Proceed with upgrade?" n
+		_q="Proceed with upgrade?"
 		;;
 
 	install)
@@ -135,24 +137,24 @@ You seem to be trying to restart an interrupted installation! You can skip
 the disk preparation steps and continue, or you can reboot and start over.
 
 __EOT
-			ask "Skip disk initialization?" n
+			_q="Skip disk initialization?"
 		else
-			ask "Proceed with install?" n
+			_q="Proceed with install?"
 		fi
 		;;
 	esac
 
-	case $resp in
-	y*|Y*)	echo "Cool!  Let's get to it..."
-		;;
-	*)	cat << __EOT
+	ask_yn "$_q"
+	if [[ $resp == n ]]; then
+		cat << __EOT
 
 Enter 'halt' at the prompt to gracefully exit OpenBSD. You can then
 power cycle the machine and boot your original OS.
 __EOT
 		exit
-		;;
-	esac
+	fi
+
+	echo "Cool!  Let's get to it..."
 }
 
 get_dkdevs() {
@@ -191,7 +193,7 @@ askpass() {
 #
 # Allow the user to escape to shells ('!') or execute commands
 # ('!foo') before entering the input.
-ask() {
+ask () {
 	local _question=$1 _default=$2
 
 	set -o noglob
@@ -226,6 +228,26 @@ ask_until () {
 	done
 }
 
+# Ask the user for a y or n, and insist on 'y', 'yes', 'n' or 'no'.
+#
+#    $1    = the question to ask the user
+#    $2    = the default answer (assumed to be 'n' if empty).
+#
+# Return 'y' or 'n' in $resp.
+ask_yn () {
+	local _q=$1 _a=${2:-no} _resp
+	typeset -l _resp
+
+	while : ; do
+		ask "$_q" "$_a"
+		_resp=$resp
+		case $_resp in
+		y|yes)	resp=y ; return ;;
+		n|no)	resp=n ; return ;;
+		esac
+	done		
+ }
+
 # Ask for the user to select a device from a list generated by scanning
 # /var/run/dmesg.boot, and make the device if it doesn't exist.
 #
@@ -343,23 +365,16 @@ save_comments () {
 edit_tmp_file () {
 	local _file=$1
 
-	ask "Edit $_file with ${EDITOR}?" n
-	case $resp in
-	y*|Y*)	${EDITOR} /tmp/$_file
-		;;
-	esac
+	ask_yn "Edit $_file with $EDITOR?"
+	[[ $resp == y ]] && $EDITOR /tmp/$_file
 }
 
 # Offer to shell out for manual network configuration, and do so if
 # the user accepts the offer.
 manual_net_cfg () {
-	ask "Do you want to do any manual network configuration?" n
+	ask_yn "Do you want to do any manual network configuration?"
 
-	case $resp in
-	y*|Y*)	echo "Type 'exit' to return to ${MODE}."
-		sh
-		;;
-	esac
+	[[ $resp == y ]] && { echo "Type 'exit' to return to $MODE." ; sh ; }
 }
 
 # log in via ftp to host $1 as user $2 with password $3
@@ -568,9 +583,9 @@ configure_ifs() {
 The default media for $_ifs is
 $(ifconfig -m $_ifs | sed -n '/supported/D;/media:/p')
 __EOT
-		ask "Do you want to change the default media?" n
+		ask_yn "Do you want to change the default media?"
 		case $resp in
-		y*|Y*)	cat << __EOT
+		y)	cat << __EOT
 Supported media options for $_ifs are:
 $_media
 __EOT
@@ -578,7 +593,7 @@ __EOT
 			_media=$resp
 			ifconfig $_ifs $_media down || return 1
 			;;
-		*)	_media=
+		n)	_media=
 			;;
 		esac
 	fi
@@ -794,10 +809,8 @@ __EOT
 	[[ -n $resp ]] || return
 	_get_sets=$resp
 
-	ask "Ready to $MODE sets?" y
-	case $resp in
-	n*|N*)	return ;;
-	esac
+	ask_yn "Ready to $MODE sets?" yes
+	[[ $resp = n ]] && return
 
 	for _f in $THESETS ; do
 		isin $_f $_get_sets || continue
@@ -858,12 +871,9 @@ install_url() {
 	[[ $resp == none ]] || export ftp_proxy=$resp http_proxy=$resp
 
 	rm -f $SERVERLIST
-	ask "Display the list of known $_url_type servers?" "${_get_server_list:-y}"
-	case $resp in
-	n*|N*)	_get_server_list=n
-		;;
-	*)
-		_get_server_list=y
+	ask_yn "Display the list of known $_url_type servers?" "${_get_server_list:-yes}"
+	_get_server_list=$resp
+	if [[ $_get_server_list == y ]]; then
 		# ftp.openbsd.org == 129.128.5.191 and will remain at
 		# that address for the forseeable future.
 		echo -n "Getting the list from 129.128.5.191 (ftp.openbsd.org)..."
@@ -878,8 +888,7 @@ install_url() {
 			echo "FAILED."
 			cat /tmp/ftplisterr
 		fi
-		;;
-	esac
+	fi
 
 	# Get server IP address or hostname
 	: ${_prompt:="Server? (IP address, hostname or 'done')"}
@@ -913,15 +922,13 @@ install_url() {
 	# Irrelevant if using a proxy.
 	if [[ $_url_type == ftp && -z $ftp_proxy ]]; then
 		case $_ftp_active in
-		-A)	resp=n ;;
-		*)	resp=y ;;
+		-A)	resp=no ;;
+		*)	resp=yes ;;
 		esac
 
-		ask "Does the server support passive mode ftp?" "$resp"
-		case $resp in
-		n*|N*)	_ftp_active=-A ;;
-		*)	unset _ftp_active ;;
-		esac
+		unset _ftp_active
+		ask_yn "Does the server support passive mode ftp?" $resp
+		[[ $resp == n ]] && _ftp_active=-A
 	fi
 
 	# Get server directory
@@ -1191,13 +1198,9 @@ install_nfs() {
 	_nfs_server_path=$resp
 
 	# Determine use of TCP
-	ask "Use TCP transport? (only works with capable NFS server)" n
-	case $resp in
-	y*|Y*)	_nfs_tcp=-T
-		;;
-	*)	_nfs_tcp=
-		;;
-	esac
+	_nfs_tcp=
+	ask_yn "Use TCP transport? (only works with capable NFS server)"
+	[[ $resp == y ]] && _nfs_tcp=-T
 
 	# Mount the server
 	if ! mount_nfs $_nfs_tcp -o ro ${_nfs_server_ip}:${_nfs_server_path} /mnt2 ; then
@@ -1582,11 +1585,8 @@ donetconfig() {
 		for _ns in $resp; do
 			echo "nameserver $_ns" >> /tmp/resolv.conf
 		done
-		ask "Use the nameserver now?" y
-		case $resp in
-		y*|Y*)	cp /tmp/resolv.conf /tmp/resolv.conf.shadow
-			;;
-		esac
+		ask_yn "Use the nameserver now?"
+		[[ $resp == y ]] && cp /tmp/resolv.conf /tmp/resolv.conf.shadow
 	fi
 
 	# Get/Confirm the default route.
@@ -1614,15 +1614,13 @@ populateusrlocal() {
 }
 
 set_machdep_apertureallowed() {
-	[ "$MDXAPERTURE" ] || return
+	[[ -n $MDXAPERTURE ]] || return
 
-	ask "Do you expect to run the X Window System?" y
-	case $resp in
-	y*|Y*)
+	ask_yn "Do you expect to run the X Window System?" yes
+	if [[ $resp == y ]]; then
 		sed -e "/^#\(machdep\.allowaperture=${MDXAPERTURE}\)/s//\1	/" \
 			/mnt/etc/sysctl.conf > /tmp/sysctl.conf
-		;;
-	esac
+	fi
 }
 
 finish_up() {