Re-implement $probe_only aspect of f_media_get_TYPE() (where TYPE is cdrom,

nfs, ftp, http, httpproxy, etc.) and f_device_get() (abstract method for
calling aforementioned f_media_get_TYPE()).

Previously, if $probe_only was present and non-NULL, the TYPE functions
would check for $file and exit with an appropriate error status (success if
the file exists and readable, failure otherwise).

While this has been retained, a pair of globals has been introduced:
$PROBE_EXIST and $PROBE_SIZE (see `/usr/share/bsdconfig/media/common.subr')

The $PROBE_EXIST global can be used where you need the functionality of
simply testing for existence (previously the _only_ functionality).

Meanwhile, the new $PROBE_SIZE global can be used to cause the TYPE function
to print the size of the file (in bytes) on standard-out (or -1) if not
found or an error occurs. NOTE: If an error occurs, it is logged with the
dprintf function, which is visible with `-d' flag or debug=1.

In many cases, where you need to get the size of a file _and_ check for its
existence, you can use the return status of a $PROBE_SIZE call.

12 files changed, 159 insertions, 81 deletions

diff --git a/usr.sbin/bsdconfig/share/media/cdrom.subr b/usr.sbin/bsdconfig/share/media/cdrom.subr
index 8ed3e96..cd68029 100644
--- a/usr.sbin/bsdconfig/share/media/cdrom.subr
+++ b/usr.sbin/bsdconfig/share/media/cdrom.subr
@@ -144,19 +144,21 @@ f_media_init_cdrom()
 	return $SUCCESS
 }
 
-# f_media_get_cdrom $device $file [$probe_only]
+# f_media_get_cdrom $device $file [$probe_type]
 #
 # Returns data from $file on a mounted CDROM device. Similar to cat(1). If
-# $probe_only is present and non-NULL, returns success if $file exists.
+# $probe_type is present and non-NULL, returns success if $file exists. If
+# $probe_type is equal to $PROBE_SIZE, prints the size of $file in bytes to
+# standard-out.
 #
 f_media_get_cdrom()
 {
-	local dev="$1" file="$2" probe_only="$3"
+	local dev="$1" file="$2" probe_type="$3"
 
-	f_dprintf "f_media_get_cdrom: dev=[%s] file=[%s] probe_only=%s" \
-	          "$dev" "$file" "$probe_only"
+	f_dprintf "f_media_get_cdrom: dev=[%s] file=[%s] probe_type=%s" \
+	          "$dev" "$file" "$probe_type"
 
-	f_media_generic_get "$MOUNTPOINT" "$file" "$probe_only"
+	f_media_generic_get "$MOUNTPOINT" "$file" "$probe_type"
 }
 
 # f_media_shutdown_cdrom $device
diff --git a/usr.sbin/bsdconfig/share/media/common.subr b/usr.sbin/bsdconfig/share/media/common.subr
index 32ad532..495aca7 100644
--- a/usr.sbin/bsdconfig/share/media/common.subr
+++ b/usr.sbin/bsdconfig/share/media/common.subr
@@ -42,6 +42,13 @@ f_include $BSDCFG_SHARE/struct.subr
 #
 MOUNTPOINT=/dist
 
+#
+# Media probe values to use for `f_media_get_TYPE media $file $PROBE' or
+# `f_device_get media $file $PROBE' (where $PROBE is one of the below values).
+#
+PROBE_EXIST=1
+PROBE_SIZE=2
+
 ############################################################ FUNCTIONS
 
 # f_media_open
@@ -83,18 +90,20 @@ f_media_verify()
 	f_struct device_media || f_media_get_type
 }
 
-# f_media_generic_get $base $file [$probe_only]
+# f_media_generic_get $base $file [$probe_type]
 #
 # A generic open which follows a well-known "path" of places to look. If
-# $probe_only is present and non-NULL, returns success if $file exists.
+# $probe_type is present and non-NULL, returns success if $file exists. If
+# $probe_type is equal to $PROBE_SIZE, prints the size of $file in bytes to
+# standard-out.
 # 
 f_media_generic_get()
 {
-	local base="$1" file="$2" probe_only="$3"
+	local base="$1" file="$2" probe_type="$3"
 
 	local fname=f_media_generic_get
-	f_dprintf "%s: base=[%s] files=[%s] probe_only=%s" \
-	          $fname "$base" "$file" "$probe_only"
+	f_dprintf "%s: base=[%s] files=[%s] probe_type=%s" \
+	          $fname "$base" "$file" "$probe_type"
 
 	local rel path
 	f_getvar $VAR_RELNAME rel
@@ -106,7 +115,17 @@ f_media_generic_get()
 	; do
 		if [ -f "$path" -a -r "$path" ]; then
 			f_dprintf "%s: file exists path=[%s]" $fname "$path"
-			[ "$probe_only" ] && return $SUCCESS
+			if [ "$probe_type" = "$PROBE_SIZE" ]; then
+				local size
+				if ! size=$( stat -f %z "$path" 2>&1 ); then
+					f_dprintf "stat: %s" "$size"
+					echo "-1"
+				else
+					f_isinteger "$size" || size=-1
+					echo $size
+				fi
+			fi
+			[ "$probe_type" ] && return $SUCCESS
 			cat "$path"
 			return
 		fi
@@ -115,8 +134,19 @@ f_media_generic_get()
 	path="$base/releases/$rel/$file" # Final path to try
 	if [ -f "$path" -a -r "$path" ]; then
 		f_dprintf "%s: file exists path=[%s]" $fname "$path"
-		[ "$probe_only" ] && return $SUCCESS
-	elif [ "$probe_only" ]; then
+		if [ "$probe_type" = "$PROBE_SIZE" ]; then
+			local size
+			if ! size=$( stat -f %z "$path" 2>&1 ); then
+				f_dprintf "stat: %s" "$size"
+				echo "-1"
+			else
+				f_isinteger "$size" || size=-1
+				echo $size
+			fi
+		fi
+		[ "$probe_type" ] && return $SUCCESS
+	elif [ "$probe_type" ]; then
+		[ "$probe_type" = "$PROBE_SIZE" ] && echo "-1"
 		return $FAILURE
 	fi
 	cat "$base/releases/$rel/$file" # Final path to try
diff --git a/usr.sbin/bsdconfig/share/media/directory.subr b/usr.sbin/bsdconfig/share/media/directory.subr
index 3efa991..3f46293 100644
--- a/usr.sbin/bsdconfig/share/media/directory.subr
+++ b/usr.sbin/bsdconfig/share/media/directory.subr
@@ -115,21 +115,22 @@ f_media_init_directory()
 	return $SUCCESS
 }
 
-# f_media_get_directory $device $file [$probe_only]
+# f_media_get_directory $device $file [$probe_type]
 #
 # Returns data from $file in the existing/current filesystem. Similar to
-# cat(1). If $probe_only is present and non-NULL, returns success if $file
-# exists.
+# cat(1). If $probe_type is present and non-NULL, returns success if $file
+# exists. If $probe_type is equal to $PROBE_SIZE, prints the size of $file in
+# bytes to standard-out.
 #
 f_media_get_directory()
 {
-	local dev="$1" file="$2" probe_only="$3" path
+	local dev="$1" file="$2" probe_type="$3" path
 
-	f_dprintf "f_media_get_directory: dev=[%s] file=[%s] probe_only=%s" \
-	          "$dev" "$file" "$probe_only"
+	f_dprintf "f_media_get_directory: dev=[%s] file=[%s] probe_type=%s" \
+	          "$dev" "$file" "$probe_type"
 
 	device_$dev get private path
-	f_media_generic_get "$path" "$file" "$probe_only"
+	f_media_generic_get "$path" "$file" "$probe_type"
 }
 
 # f_media_shutdown_directory $device
diff --git a/usr.sbin/bsdconfig/share/media/dos.subr b/usr.sbin/bsdconfig/share/media/dos.subr
index 068ef59..440c5c9 100644
--- a/usr.sbin/bsdconfig/share/media/dos.subr
+++ b/usr.sbin/bsdconfig/share/media/dos.subr
@@ -122,19 +122,21 @@ f_media_init_dos()
 	return $SUCCESS
 }
 
-# f_media_get_dos $device $file [$probe_only]
+# f_media_get_dos $device $file [$probe_type]
 #
 # Returns data from $file on a mounted DOS partition device. Similar to cat(1).
-# If $probe_only is present and non-NULL, returns success if $file exists.
+# If $probe_type is present and non-NULL, returns success if $file exists. If
+# $probe_type is equal to $PROBE_SIZE, prints the size of $file in bytes to
+# standard-out.
 #
 f_media_get_dos()
 {
-	local dev="$1" file="$2" probe_only="$3"
+	local dev="$1" file="$2" probe_type="$3"
 
-	f_dprintf "f_media_get_dos: dev=[%s] file=[%s] probe_only=%s" \
-	          "$dev" "$file" "$probe_only"
+	f_dprintf "f_media_get_dos: dev=[%s] file=[%s] probe_type=%s" \
+	          "$dev" "$file" "$probe_type"
 
-	f_media_generic_get "$MOUNTPOINT" "$file" "$probe_only"
+	f_media_generic_get "$MOUNTPOINT" "$file" "$probe_type"
 }
 
 # f_media_shutdown_dos $device
diff --git a/usr.sbin/bsdconfig/share/media/floppy.subr b/usr.sbin/bsdconfig/share/media/floppy.subr
index ac05937..eb6bc5e 100644
--- a/usr.sbin/bsdconfig/share/media/floppy.subr
+++ b/usr.sbin/bsdconfig/share/media/floppy.subr
@@ -144,17 +144,19 @@ f_media_init_floppy()
 	return $SUCCESS
 }
 
-# f_media_get_floppy $device $file [$probe_only]
+# f_media_get_floppy $device $file [$probe_type]
 #
 # Returns data from $file on a mounted Floppy disk device. Similar to cat(1).
-# If $probe_only is present and non-null, limits retries to zero.
+# If $probe_type is present and non-NULL, limits retries to zero and returns
+# success if $file exists. If $probe_type is equal to $PROBE_SIZE, prints the
+# size of $file in bytes to standard-out.
 #
 f_media_get_floppy()
 {
-	local dev="$1" file="$2" probe_only="$3"
+	local dev="$1" file="$2" probe_type="$3"
 
-	f_dprintf "f_media_get_floppy: dev=[%s] file=[%s] probe_only=%s" \
-	          "$dev" "$file" "$probe_only"
+	f_dprintf "f_media_get_floppy: dev=[%s] file=[%s] probe_type=%s" \
+	          "$dev" "$file" "$probe_type"
 
 	#
 	# floppies don't use f_media_generic_get() because it's too expensive
@@ -166,11 +168,13 @@ f_media_get_floppy()
 	local fp="${mp:=$MOUNTPOINT}/$file"
 	if ! [ -f "$fp" -a -r "$fp" ]; then
 		local nretries=4
-		[ "$probe_only" ] && return $FAILURE
+		[ "$probe_type" = "$PROBE_SIZE" ] && echo "-1"
+		[ "$probe_type" ] && return $FAILURE
 		while ! [ -f "$fp" -a -r "$fp" ]; do
 			if [ $nretries -eq 0 ]; then
 				f_show_msg "$msg_failed_to_get_floppy_file" \
 				           "$fp"
+				[ "$probe_type" = "$PROBE_SIZE" ] && echo "-1"
 				return $FAILURE
 			fi
 			FLOPPY_DISTWANTED="$fp"
@@ -178,9 +182,17 @@ f_media_get_floppy()
 			f_media_init_floppy "$dev" || return $FAILURE
 			nretries=$(( $nretries - 1 ))
 		done
-	elif [ "$probe_only" ]; then
-		return $SUCCESS
 	fi
+	#
+	# If we reach here, $file exists
+	#
+	if [ "$probe_type" = "$PROBE_SIZE" ]; then
+		local size
+		size=$( stat -f %z "$fp" 2>&1 ) || f_dprintf "stat: %s" "$size"
+		f_isinteger "$size" || size=-1
+		echo "$size"
+	fi
+	[ "$probe_type" ] && return $SUCCESS
 	cat "$fp"
 }
 
diff --git a/usr.sbin/bsdconfig/share/media/ftp.subr b/usr.sbin/bsdconfig/share/media/ftp.subr
index ac46a27..638584c 100644
--- a/usr.sbin/bsdconfig/share/media/ftp.subr
+++ b/usr.sbin/bsdconfig/share/media/ftp.subr
@@ -787,12 +787,13 @@ f_media_init_ftp()
 	return $FAILURE
 }
 
-# f_media_get_ftp $device $file [$probe_only]
+# f_media_get_ftp $device $file [$probe_type]
 #
 # Returns data from $file on an FTP server using ftp(1). Please note that
 # $device is unused but must be present (even if null). Information is instead
-# gathered from the environment. If $probe_only is present and non-NULL,
-# returns success if $file exists.
+# gathered from the environment. If $probe_type is present and non-NULL,
+# returns success if $file exists. If $probe_type is equal to $PROBE_SIZE,
+# prints the size of $file in bytes to standard-out.
 #
 # Variables from variable.subr used to configure the connection are as follows
 # (all of which are configured by f_media_set_ftp above):
@@ -826,10 +827,10 @@ f_media_init_ftp()
 #
 f_media_get_ftp()
 {
-	local dev="$1" file="$2" probe_only="$3" hosts=
+	local dev="$1" file="$2" probe_type="$3" hosts=
 
-	f_dprintf "f_media_get_ftp: dev=[%s] file=[%s] probe_only=%s" \
-	          "$dev" "$file" "$probe_only"
+	f_dprintf "f_media_get_ftp: dev=[%s] file=[%s] probe_type=%s" \
+	          "$dev" "$file" "$probe_type"
 
 	local ftp_host ftp_port
 	f_getvar $VAR_FTP_HOST ftp_host
@@ -899,14 +900,16 @@ f_media_get_ftp()
 
 	f_dprintf "sending ftp request for: %s" "ftp://$host$port/$dir/$file"
 
-	if [ "$probe_only" ]; then
-		local url="ftp://$userpass$host$port/$dir/$file"
+	if [ "$probe_type" ]; then
+		local url="ftp://$userpass$host$port/$dir/$file" size
 		[ "$use_anon" ] && url="ftp://$host$port/$dir/$file"
 		if ! size=$( fetch -s "$url" 2>&1 ) || ! f_isinteger "$size"
 		then
 			f_dprintf "request failed! size response=[%s]" "$size"
+			[ "$probe_type" = "$PROBE_SIZE" ] && echo "-1"
 			return $FAILURE
 		fi
+		[ "$probe_type" = "$PROBE_SIZE" ] && echo "$size"
 		return $SUCCESS
 	fi
 
diff --git a/usr.sbin/bsdconfig/share/media/http.subr b/usr.sbin/bsdconfig/share/media/http.subr
index a904d01..1236c99 100644
--- a/usr.sbin/bsdconfig/share/media/http.subr
+++ b/usr.sbin/bsdconfig/share/media/http.subr
@@ -510,13 +510,15 @@ f_media_init_http()
 	return $http_found
 }
 
-# f_media_get_http $device $file [$probe_only]
+# f_media_get_http $device $file [$probe_type]
 #
 # Returns data from $file on an HTTP server using nc(1). Please note that
 # $device is unused but must be present (even if null). Information is instead
-# gathered from the environment. If $probe_only is both present and non-NULL,
+# gathered from the environment. If $probe_type is both present and non-NULL,
 # this function exits after receiving the HTTP header response from the server
 # (if the HTTP response code is 200, success is returned; otherwise failure).
+# If $probe_type is equal to $PROBE_SIZE, prints the content-length in bytes
+# from the response (or -1 if not found) to standard-out.
 #
 # The variables used to configure the connection are as follows (all of which
 # are configured by f_media_set_http above):
@@ -542,10 +544,10 @@ f_media_init_http()
 #
 f_media_get_http()
 {
-	local dev="$1" file="$2" probe_only="$3" hosts=
+	local dev="$1" file="$2" probe_type="$3" hosts=
 
-	f_dprintf "f_media_get_http: dev=[%s] file=[%s] probe_only=%s" \
-	          "$dev" "$file" "$probe_only"
+	f_dprintf "f_media_get_http: dev=[%s] file=[%s] probe_type=%s" \
+	          "$dev" "$file" "$probe_type"
 
 	local http_host http_port
 	f_getvar $VAR_HTTP_HOST http_host
@@ -591,7 +593,7 @@ f_media_get_http()
 		# this is extremely quick'n dirty
 		#
 
-		rv=0
+		rv=0 length=-1
 		while read LINE; do
 			case "$LINE" in
 			HTTP*)
@@ -599,6 +601,12 @@ f_media_get_http()
 				set -- $LINE; rv=$2
 				f_isinteger "$rv" || rv=0
 				;;
+			"Content-Length: "*)
+				length="${LINE%
}"
+				length="${length#Content-Length: }"
+				f_dprintf "received content-length: %s" \
+				          "$length"
+				;;
 			*)
 				[ "${LINE%
}" ] || break # End of headers
 			esac
@@ -610,14 +618,17 @@ f_media_get_http()
 		[ $rv -ge 300 ] && exit 3
 		[ $rv -eq 200 ] || exit $FAILURE
 
-		if [ ! "$probe_only" ]; then
+		if [ ! "$probe_type" ]; then
 			cat # output the rest ``as-is''
+		elif [ "$probe_type" = "$PROBE_SIZE" ]; then
+			f_isinteger "$length" || length=-1
+			echo "$length"
 		fi
 		exit 200
 	)
 	local retval=$?
 	[ $retval -eq 200 ] && return $SUCCESS
-	[ "$probe_only" ] && return $FAILURE
+	[ "$probe_type" ] && return $FAILURE
 
 	case "$retval" in
 	  5) f_show_msg "$msg_server_error_when_requesting_url" "$url" ;;
diff --git a/usr.sbin/bsdconfig/share/media/httpproxy.subr b/usr.sbin/bsdconfig/share/media/httpproxy.subr
index 817cf0d..66e5be4 100644
--- a/usr.sbin/bsdconfig/share/media/httpproxy.subr
+++ b/usr.sbin/bsdconfig/share/media/httpproxy.subr
@@ -329,14 +329,16 @@ f_media_init_http_proxy()
 	return $http_found
 }
 
-# f_media_get_http_proxy $device $file [$probe_only]
+# f_media_get_http_proxy $device $file [$probe_type]
 #
 # Returns data from $file on an FTP server via HTTP proxy using nc(1). Please
 # note that $device is unused but must be present (even if null). Information
-# is instead gathered from the environment. If $probe_only is both present and
+# is instead gathered from the environment. If $probe_type is both present and
 # non-NULL, this function exits after receiving the HTTP header response from
 # the proxy server (if the HTTP response code is 200, success is returned;
-# otherwise failure).
+# otherwise failure). If $probe_type is equal to $PROBE_SIZE, prints the
+# content-length in bytes from the response (or -1 if not found) to standard-
+# out.
 #
 # The variables used to configure the connection are as follows (all of which
 # are configured by f_media_set_http_proxy above):
@@ -358,10 +360,10 @@ f_media_init_http_proxy()
 #
 f_media_get_http_proxy()
 {
-	local dev="$1" file="$2" probe_only="$3" hosts=
+	local dev="$1" file="$2" probe_type="$3" hosts=
 
-	f_dprintf "f_media_get_http_proxy: dev=[%s] file=[%s] probe_only=%s" \
-	          "$dev" "$file" "$probe_only"
+	f_dprintf "f_media_get_http_proxy: dev=[%s] file=[%s] probe_type=%s" \
+	          "$dev" "$file" "$probe_type"
 
 	local proxy_host proxy_port
 	f_getvar $VAR_HTTP_PROXY_HOST proxy_host
@@ -408,7 +410,7 @@ f_media_get_http_proxy()
 		# this is extremely quick'n dirty
 		#
 
-		rv=0
+		rv=0 length=-1
 		while read LINE; do
 			case "$LINE" in
 			HTTP*)
@@ -416,6 +418,12 @@ f_media_get_http_proxy()
 				set -- $LINE; rv=$2
 				f_isinteger "$rv" || rv=0
 				;;
+			"Content-Length: "*)
+				length="${LINE%
}"
+				length="${length#Content-Length: }"
+				f_dprintf "received content-length: %s" \
+				          "$length"
+				;;
 			*)
 				[ "${LINE%
}" ] || break # End of headers
 			esac
@@ -427,14 +435,17 @@ f_media_get_http_proxy()
 		[ $rv -ge 300 ] && exit 3
 		[ $rv -eq 200 ] || exit $FAILURE
 
-		if [ ! "$probe_only" ]; then
+		if [ ! "$probe_type" ]; then
 			cat # output the rest ``as-is''
+		elif [ "$probe_type" = "$PROBE_SIZE" ]; then
+			f_isinteger "$length" || length=-1
+			echo "$length"
 		fi
 		exit 200
 	)
 	local retval=$?
 	[ $retval -eq 200 ] && return $SUCCESS
-	[ "$probe_only" ] && return $FAILURE
+	[ "$probe_type" ] && return $FAILURE
 
 	case "$retval" in
 	  5) f_show_msg "$msg_server_error_when_requesting_url" "$url" ;;
diff --git a/usr.sbin/bsdconfig/share/media/nfs.subr b/usr.sbin/bsdconfig/share/media/nfs.subr
index 93089cb..9ce0467 100644
--- a/usr.sbin/bsdconfig/share/media/nfs.subr
+++ b/usr.sbin/bsdconfig/share/media/nfs.subr
@@ -208,19 +208,21 @@ f_media_init_nfs()
 	return $SUCCESS
 }
 
-# f_media_get_nfs $device $file [$probe_only]
+# f_media_get_nfs $device $file [$probe_type]
 #
 # Returns data from $file on a mounted NFS device. Similar to cat(1). If
-# $probe_only is present and non-NULL, returns success if $file exists.
+# $probe_type is present and non-NULL, returns success if $file exists. If
+# $probe_type is equal to $PROBE_SIZE, prints the size of $file in bytes to
+# standard-out.
 #
 f_media_get_nfs()
 {
-	local dev="$1" file="$2" probe_only="$3"
+	local dev="$1" file="$2" probe_type="$3"
 
-	f_dprintf "f_media_get_nfs: dev=[%s] file=[%s] probe_only=%s" \
-	          "$dev" "$file" "$probe_only"
+	f_dprintf "f_media_get_nfs: dev=[%s] file=[%s] probe_type=%s" \
+	          "$dev" "$file" "$probe_type"
 
-	f_media_generic_get "$MOUNTPOINT" "$file" "$probe_only"
+	f_media_generic_get "$MOUNTPOINT" "$file" "$probe_type"
 }
 
 # f_media_shutdown_nfs $device
diff --git a/usr.sbin/bsdconfig/share/media/ufs.subr b/usr.sbin/bsdconfig/share/media/ufs.subr
index 63094c1..cc63475 100644
--- a/usr.sbin/bsdconfig/share/media/ufs.subr
+++ b/usr.sbin/bsdconfig/share/media/ufs.subr
@@ -152,19 +152,21 @@ f_media_init_ufs()
 	return $SUCCESS
 }
 
-# f_media_get_ufs $device $file [$probe_only]
+# f_media_get_ufs $device $file [$probe_type]
 #
 # Returns data from $file on a mounted UFS partition device. Similar to cat(1).
-# If $probe_only is present and non-NULL, returns success if $file exists.
+# If $probe_type is present and non-NULL, returns success if $file exists. If
+# $probe_type is equal to $PROBE_SIZE, prints the size of $file in bytes to
+# standard-out.
 #
 f_media_get_ufs()
 {
-	local dev="$1" file="$2" probe_only="$3"
+	local dev="$1" file="$2" probe_type="$3"
 
-	f_dprintf "f_media_get_ufs: dev=[%s] file=[%s] probe_only=%s" \
-	          "$dev" "$file" "$probe_only"
+	f_dprintf "f_media_get_ufs: dev=[%s] file=[%s] probe_type=%s" \
+	          "$dev" "$file" "$probe_type"
 
-	f_media_generic_get "$MOUNTPOINT" "$file" "$probe_only"
+	f_media_generic_get "$MOUNTPOINT" "$file" "$probe_type"
 }
 
 # f_media_shutdown_ufs $device
diff --git a/usr.sbin/bsdconfig/share/media/usb.subr b/usr.sbin/bsdconfig/share/media/usb.subr
index aa47b20..e345ae0 100644
--- a/usr.sbin/bsdconfig/share/media/usb.subr
+++ b/usr.sbin/bsdconfig/share/media/usb.subr
@@ -132,19 +132,21 @@ f_media_init_usb()
 	return $FAILURE
 }
 
-# f_media_get_usb $device $file [$probe_only]
+# f_media_get_usb $device $file [$probe_type]
 #
-# Returns data from $file on a mounted USB disk device. Similar to cat(1).
-# If $probe_only is present and non-NULL, returns success if $file exists.
+# Returns data from $file on a mounted USB disk device. Similar to cat(1). If
+# $probe_type is present and non-NULL, returns success if $file exists. If
+# $probe_type is equal to $PROBE_SIZE, prints the size of $file in bytes to
+# standard-out.
 #
 f_media_get_usb()
 {
-	local dev="$1" file="$2" probe_only="$3"
+	local dev="$1" file="$2" probe_type="$3"
 
-	f_dprintf "f_media_get_usb: dev=[%s] file=[%s] probe_only=%s" \
-	          "$dev" "$file" "$probe_only"
+	f_dprintf "f_media_get_usb: dev=[%s] file=[%s] probe_type=%s" \
+	          "$dev" "$file" "$probe_type"
 
-	f_media_generic_get "$MOUNTPOINT" "$file" "$probe_only"
+	f_media_generic_get "$MOUNTPOINT" "$file" "$probe_type"
 }
 
 # f_media_shutdown_usb $device
diff --git a/usr.sbin/bsdconfig/share/packages/packages.subr b/usr.sbin/bsdconfig/share/packages/packages.subr
index 75d5244..e447b2e 100755
--- a/usr.sbin/bsdconfig/share/packages/packages.subr
+++ b/usr.sbin/bsdconfig/share/packages/packages.subr
@@ -993,9 +993,9 @@ f_package_extract()
 	esac
 
 	# We have a path, call the device strategy routine to get the file
-	local pkg_ext probe_only=1 found=
+	local pkg_ext found=
 	for pkg_ext in "" $PACKAGE_EXTENSIONS; do
-		if f_device_get $device "$path$pkg_ext" $probe_only; then
+		if f_device_get $device "$path$pkg_ext" $PROBE_EXIST; then
 			path="$path$pkg_ext"
 			f_dprintf "%s: found path=[%s] dev=[%s]" \
 			          $fname "$path" "$device"