base-files: add -h and --help options to sysupgrade (#9728)

SVN-Revision: 27630

package/base-files/Makefile

@@ -10,7 +10,7 @@ include $(TOPDIR)/rules.mk
 include $(INCLUDE_DIR)/kernel.mk
 
 PKG_NAME:=base-files
-PKG_RELEASE:=74
+PKG_RELEASE:=75
 
 PKG_FILE_DEPENDS:=$(PLATFORM_DIR)/ $(GENERIC_PLATFORM_DIR)/base-files/
 PKG_BUILD_DEPENDS:=opkg/host

package/base-files/files/sbin/sysupgrade

@@ -10,6 +10,7 @@ export SAVE_CONFIG=1
 export SAVE_OVERLAY=0
 export DELAY=
 export CONF_IMAGE=
+export HELP=0
 
 # parse options
 while [ -n "$1" ]; do 
@@ -21,6 +22,7 @@ while [ -n "$1" ]; do
 		-n) export SAVE_CONFIG=0;;
 		-c) export SAVE_OVERLAY=1;;
 		-f) export CONF_IMAGE="$2"; shift;;
+		-h|--help) export HELP=1; break;;
 		-*)
 			echo "Invalid option: $1"
 			exit 1
@@ -36,7 +38,7 @@ export CONF_TAR=/tmp/sysupgrade.tgz
 export ARGV="$*"
 export ARGC="$#"
 
-[ -z "$ARGV" ] && {
+[ -z "$ARGV" -o $HELP -gt 0 ] && {
 	cat <<EOF
 Usage: $0 [options] <image file or URL>
 
@@ -48,6 +50,7 @@ Options:
 	-n           do not save configuration over reflash
 	-q           less verbose
 	-v           more verbose
+	-h / --help  display this help
 
 EOF
 	exit 1