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

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

diff --git a/bin/live-snapshot b/bin/live-snapshot
index b523c4a..67e853a 100755 (executable)
--- a/bin/live-snapshot
+++ b/bin/live-snapshot
@@ -26,26 +26,35 @@
 # 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"
 
 # Permits multiple runs
 MOUNTP="$(mktemp -d -p ${SAFE_TMPDIR} live-snapshot-mnt.XXXXXX)"
+DEST="${MOUNTP}/live-sn.cpio.gz"
+
+# Command line defaults and declarations
 SNAP_COW="/live/cow"
 SNAP_DEV=""
-DEST="${MOUNTP}/live-sn.cpio.gz"
-SNAP_TYPE="cpio"
-DESKTOP_LINK="/home/${USERNAME}/Desktop/live-snapshot"
+SNAP_OUTPUT=""
 SNAP_RESYNC_STRING=""
+SNAP_TYPE="cpio"
 
 Error ()
 {
@@ -64,6 +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]"
@@ -79,6 +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."
@@ -125,16 +136,24 @@ Version ()
        exit 0
 }
 
-Is_same_mount ()
+Try_refresh ()
 {
-       dir1="$(Base_path ${1})"
-       dir2="$(Base_path ${2})"
+       FOUND=""
+       if [ -n "${ROOTSNAP}" ]; then
+               "${EXECUTABLE}" --resync-string="${ROOTSNAP}"
+               FOUND="Yes"
+       fi
 
-       if [ "${dir1}" = "${dir2}" ]
+       if [ -n "${HOMESNAP}" ]; then
+               "${EXECUTABLE}" --resync-string="${HOMESNAP}"
+               FOUND="Yes"
+       fi
+
+       if [ -z "${FOUND}" ]
        then
-               return 0
-       else
-               return 1
+               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
 }
 
@@ -142,7 +161,7 @@ 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}"
 
@@ -174,6 +193,11 @@ Parse_args ()
                                break
                                ;;
 
+                       -f|--refresh)
+                               Try_refresh
+                               exit 0
+                               ;;
+
                        -h|--help)
                                Help
                                ;;
@@ -228,7 +252,8 @@ Defaults ()
                                Error "unrecognized resync string"
                                ;;
                esac
-       else
+       elif [ -z "${SNAP_OUTPUT}" ]
+       then
                # Set target file based on image
                case "${SNAP_TYPE}" in
                        cpio)
@@ -243,6 +268,8 @@ Defaults ()
                                DEST="${MOUNTP}/live-sn.ext2"
                                ;;
                esac
+       else
+               DEST="${SNAP_OUTPUT}"
        fi
 }
 
@@ -270,8 +297,6 @@ Validate_input ()
 
 Mount_device ()
 {
-       mkdir -p "${MOUNTP}"
-
        case "${SNAP_DEV}" in
                "")
                        # create a temp
@@ -318,7 +343,7 @@ Do_snapshot ()
 
 Clean ()
 {
-       if echo "${DEST}" | grep -q "${MOUNTP}"
+       if [ -z "${SNAP_RESYNC_STRING}" ] && echo "${DEST}" | grep -q "${MOUNTP}"
        then
                echo "${DEST} is present on ${MOUNTP}, therefore no automatic unmounting the latter." > /dev/null 1>&2
        else