live-snapshot: new "--refresh" option.

[live-boot-grml.git] / bin / live-snapshot

diff --git a/bin/live-snapshot b/bin/live-snapshot
index 7e68c59..67e853a 100755 (executable)
--- a/bin/live-snapshot
+++ b/bin/live-snapshot
@@ -26,14 +26,21 @@
 # On Debian systems, the complete text of the GNU General Public License
 # can be found in /usr/share/common-licenses/GPL-2 file.
 
+# declare here two vars from /etc/live.conf because of "set -u"
+ROOTSNAP=""
+HOMESNAP=""
+
 set -eu
 
 . /usr/share/initramfs-tools/scripts/live-helpers
-. /etc/live.conf
+
+LIVE_CONF="/etc/live.conf"
+. "${LIVE_CONF}"
 
 export USERNAME USERFULLNAME HOSTNAME
 
-PROGRAM="$(basename $0)"
+EXECUTABLE="${0}"
+PROGRAM=$(basename "${EXECUTABLE}")
 
 # Needs to be available at run and reboot time
 SAFE_TMPDIR="/live"
@@ -66,6 +73,7 @@ Header ()
        echo
        echo "usage: ${PROGRAM} [-c|--cow DIRECTORY] [-d|--device DEVICE] [-o|--output FILE] [-t|--type TYPE]"
        echo "       ${PROGRAM} [-r|--resync-string STRING]"
+       echo "       ${PROGRAM} [-f|--refresh]"
        echo "       ${PROGRAM} [-h|--help]"
        echo "       ${PROGRAM} [-u|--usage]"
        echo "       ${PROGRAM} [-v|--version]"
@@ -81,6 +89,7 @@ Help ()
        echo "  -d, --device: output snapshot device (default: ${SNAP_DEV:-auto})."
        echo "  -o, --output: output image file (default: ${DEST})."
        echo "  -r, --resync-string: internally used to resync previous made snapshots."
+       echo "  -f, --refresh: try to sync a running snapshot."
        echo "  -t, --type: snapshot filesystem type. Options: \"squashfs\", \"ext2\", \"ext3\", \"jffs2\" or \"cpio\".gz archive (default: ${SNAP_TYPE})"
        echo
        echo "Look at live-snapshot(1) man page for more information."
@@ -127,11 +136,32 @@ Version ()
        exit 0
 }
 
+Try_refresh ()
+{
+       FOUND=""
+       if [ -n "${ROOTSNAP}" ]; then
+               "${EXECUTABLE}" --resync-string="${ROOTSNAP}"
+               FOUND="Yes"
+       fi
+
+       if [ -n "${HOMESNAP}" ]; then
+               "${EXECUTABLE}" --resync-string="${HOMESNAP}"
+               FOUND="Yes"
+       fi
+
+       if [ -z "${FOUND}" ]
+       then
+               echo "No autoconfigured snapshots found at boot;" > /dev/null 1>&2
+               echo "(no resync string in ${LIVE_CONF})." > /dev/null 1>&2
+               exit 1
+       fi
+}
+
 Parse_args ()
 {
        # Parse command line
        ARGS="${*}"
-       ARGUMENTS="$(getopt --longoptions cow:,device:,output,resync-string:,type:,help,usage,version --name=${PROGRAM} --options c:d:o:t:r:,h,u,v --shell sh -- ${ARGS})"
+       ARGUMENTS="$(getopt --longoptions cow:,device:,output,resync-string:,refresh,type:,help,usage,version --name=${PROGRAM} --options c:d:o:t:r:fhuv --shell sh -- ${ARGS})"
 
        eval set -- "${ARGUMENTS}"
 
@@ -163,6 +193,11 @@ Parse_args ()
                                break
                                ;;
 
+                       -f|--refresh)
+                               Try_refresh
+                               exit 0
+                               ;;
+
                        -h|--help)
                                Help
                                ;;