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.

1 files changed, 11 insertions, 8 deletions

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