Robert Bruce Park
12deac25d6
Code was assuming that you'd run backups hourly, eg, so you'd have many backups within the last 24 hours. Code assumed that by the time you found a backup more than 24h old, you'd already have a value for $prev set. In the event that your most recent backup is more than 24 hours old, $prev would not be set and bash would get an error "unary operator expected" when it tried to compare the day of the newest backup to the empty $prev value. I fix this by setting a default value for $prev, one that cannot be mistaken for an existing backup because it does not represent a valid date. This ensures that the most recent backup is correctly preserved regardless of it's age.
281 lines
8.8 KiB
Bash
281 lines
8.8 KiB
Bash
#!/usr/bin/env bash
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# -----------------------------------------------------------------------------
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# Log functions
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# -----------------------------------------------------------------------------
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fn_log_info() {
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echo "rsync_tmbackup: $1"
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}
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fn_log_warn() {
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echo "rsync_tmbackup: [WARNING] $1"
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}
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fn_log_error() {
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echo "rsync_tmbackup: [ERROR] $1"
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}
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# -----------------------------------------------------------------------------
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# Make sure everything really stops when CTRL+C is pressed
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# -----------------------------------------------------------------------------
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fn_terminate_script() {
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echo "rsync_tmbackup: SIGINT caught."
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exit 1
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}
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trap 'fn_terminate_script' SIGINT
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# -----------------------------------------------------------------------------
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# Small utility functions for reducing code duplication
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# -----------------------------------------------------------------------------
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fn_parse_date() {
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# Converts YYYY-MM-DD-HHMMSS to YYYY-MM-DD HH:MM:SS and then to Unix Epoch.
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date -d "${1:0:10} ${1:11:2}:${1:13:2}:${1:15:2}" +%s
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}
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fn_find_backups() {
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find "$DEST_FOLDER" -type d -name "????-??-??-??????" -prune
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}
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fn_expire_backup() {
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# Double-check that we're on a backup destination to be completely
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# sure we're deleting the right folder
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if [ -z "$(fn_is_backup_destination "$(dirname -- "$1")")" ]; then
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fn_log_error "$1 is not on a backup destination - aborting."
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exit 1
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fi
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fn_log_info "Expiring $1"
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rm -rf -- "$1"
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}
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# -----------------------------------------------------------------------------
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# Source and destination information
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# -----------------------------------------------------------------------------
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SRC_FOLDER=${1%/}
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DEST_FOLDER=${2%/}
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EXCLUSION_FILE=$3
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for arg in "$SRC_FOLDER" "$DEST_FOLDER" "$EXCLUSION_FILE"; do
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if [[ "$arg" == *"'"* ]]; then
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fn_log_error 'Arguments may not have any single quote characters.'
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exit 1
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fi
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done
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# -----------------------------------------------------------------------------
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# Check that the destination drive is a backup drive
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# -----------------------------------------------------------------------------
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# TODO: check that the destination supports hard links
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fn_backup_marker_path() {
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echo "$1/backup.marker"
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}
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fn_is_backup_destination() {
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find "$(fn_backup_marker_path "$1")" 2>/dev/null
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}
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if [ -z "$(fn_is_backup_destination $DEST_FOLDER)" ]; then
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fn_log_info "Safety check failed - the destination does not appear to be a backup folder or drive (marker file not found)."
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fn_log_info "If it is indeed a backup folder, you may add the marker file by running the following command:"
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fn_log_info ""
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fn_log_info "touch \"$(fn_backup_marker_path $DEST_FOLDER)\""
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fn_log_info ""
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exit 1
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fi
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# -----------------------------------------------------------------------------
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# Setup additional variables
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# -----------------------------------------------------------------------------
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export IFS=$'\n' # Better for handling spaces in filenames.
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NOW=$(date +"%Y-%m-%d-%H%M%S")
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PROFILE_FOLDER="$HOME/.rsync_tmbackup"
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LOG_FILE="$PROFILE_FOLDER/$NOW.log"
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DEST=$DEST_FOLDER/$NOW
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PREVIOUS_DEST=$(fn_find_backups | sort | tail -n 1)
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INPROGRESS_FILE=$DEST_FOLDER/backup.inprogress
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KEEP_ALL_DATE=$(date -d '-1 day' +%s)
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KEEP_DAILIES_DATE=$(date -d '-1 month' +%s)
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# -----------------------------------------------------------------------------
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# Create profile folder if it doesn't exist
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# -----------------------------------------------------------------------------
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if [ ! -d "$PROFILE_FOLDER" ]; then
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fn_log_info "Creating profile folder in '$PROFILE_FOLDER'..."
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mkdir -- "$PROFILE_FOLDER"
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fi
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# -----------------------------------------------------------------------------
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# Handle case where a previous backup failed or was interrupted.
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# -----------------------------------------------------------------------------
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if [ -f "$INPROGRESS_FILE" ]; then
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if [ "$PREVIOUS_DEST" != "" ]; then
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# - Last backup is moved to current backup folder so that it can be resumed.
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# - 2nd to last backup becomes last backup.
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fn_log_info "$INPROGRESS_FILE already exists - the previous backup failed or was interrupted. Backup will resume from there."
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LINE_COUNT=$(fn_find_backups | sort | tail -n 2 | wc -l)
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mv -- "$PREVIOUS_DEST" "$DEST"
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if [ "$LINE_COUNT" -gt 1 ]; then
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PREVIOUS_PREVIOUS_DEST=$(fn_find_backups | sort | tail -n 2 | head -n 1)
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PREVIOUS_DEST=$PREVIOUS_PREVIOUS_DEST
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else
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PREVIOUS_DEST=""
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fi
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fi
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fi
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# Run in a loop to handle the "No space left on device" logic.
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while [ "1" ]; do
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# -----------------------------------------------------------------------------
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# Check if we are doing an incremental backup (if previous backup exists) or not
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# -----------------------------------------------------------------------------
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LINK_DEST_OPTION=""
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if [ "$PREVIOUS_DEST" == "" ]; then
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fn_log_info "No previous backup - creating new one."
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else
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# If the path is relative, it needs to be relative to the destination. To keep
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# it simple, just use an absolute path. See http://serverfault.com/a/210058/118679
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PREVIOUS_DEST=`cd \`dirname -- "$PREVIOUS_DEST"\`; pwd`"/"`basename -- "$PREVIOUS_DEST"`
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fn_log_info "Previous backup found - doing incremental backup from $PREVIOUS_DEST"
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LINK_DEST_OPTION="--link-dest=$PREVIOUS_DEST"
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fi
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# -----------------------------------------------------------------------------
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# Create destination folder if it doesn't already exists
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# -----------------------------------------------------------------------------
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if [ ! -d "$DEST" ]; then
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fn_log_info "Creating destination $DEST"
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mkdir -p -- "$DEST"
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fi
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# -----------------------------------------------------------------------------
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# Purge certain old backups before beginning new backup.
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# -----------------------------------------------------------------------------
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# Default value for $prev ensures that the most recent backup is never deleted.
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prev="0000-00-00-000000"
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for fname in $(fn_find_backups | sort -r); do
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date=$(basename "$fname")
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stamp=$(fn_parse_date $date)
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# Skip if failed to parse date...
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[ -n "$stamp" ] || continue
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if [ $stamp -ge $KEEP_ALL_DATE ]; then
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true
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elif [ $stamp -ge $KEEP_DAILIES_DATE ]; then
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# Delete all but the most recent of each day.
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[ ${date:8:2} -eq ${prev:8:2} ] && fn_expire_backup "$fname"
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else
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# Delete all but the most recent of each month.
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[ ${date:5:2} -eq ${prev:5:2} ] && fn_expire_backup "$fname"
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fi
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prev=$date
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done
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# -----------------------------------------------------------------------------
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# Start backup
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# -----------------------------------------------------------------------------
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LOG_FILE="$PROFILE_FOLDER/$(date +"%Y-%m-%d-%H%M%S").log"
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fn_log_info "Starting backup..."
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fn_log_info "From: $SRC_FOLDER"
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fn_log_info "To: $DEST"
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CMD="rsync"
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CMD="$CMD --compress"
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CMD="$CMD --numeric-ids"
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CMD="$CMD --links"
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CMD="$CMD --hard-links"
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CMD="$CMD --delete"
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CMD="$CMD --delete-excluded"
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CMD="$CMD --one-file-system"
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CMD="$CMD --archive"
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CMD="$CMD --itemize-changes"
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CMD="$CMD --verbose"
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CMD="$CMD --log-file '$LOG_FILE'"
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if [ "$EXCLUSION_FILE" != "" ]; then
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# We've already checked that $EXCLUSION_FILE doesn't contain a single quote
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CMD="$CMD --exclude-from '$EXCLUSION_FILE'"
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fi
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CMD="$CMD $LINK_DEST_OPTION"
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CMD="$CMD -- '$SRC_FOLDER/' '$DEST/'"
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CMD="$CMD | grep -E '^deleting|[^/]$'"
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fn_log_info "Running command:"
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fn_log_info "$CMD"
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touch -- "$INPROGRESS_FILE"
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eval $CMD
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RSYNC_EXIT_CODE=$?
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# -----------------------------------------------------------------------------
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# Check if we ran out of space
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# -----------------------------------------------------------------------------
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# TODO: find better way to check for out of space condition without parsing log.
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grep --quiet "No space left on device (28)" "$LOG_FILE"
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NO_SPACE_LEFT="$?"
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if [ "$NO_SPACE_LEFT" != "0" ]; then
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# This error might also happen if there is no space left
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grep --quiet "Result too large (34)" "$LOG_FILE"
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NO_SPACE_LEFT="$?"
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fi
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rm -- "$LOG_FILE"
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if [ "$NO_SPACE_LEFT" == "0" ]; then
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# TODO: -y flag
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read -p "It looks like there is no space left on the destination. Delete old backup? (Y/n) " yn
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case $yn in
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[Nn]* ) exit 0;;
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esac
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fn_log_warn "No space left on device - removing oldest backup and resuming."
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BACKUP_FOLDER_COUNT=$(fn_find_backups | wc -l)
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if [ "$BACKUP_FOLDER_COUNT" -lt "2" ]; then
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fn_log_error "No space left on device, and no old backup to delete."
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exit 1
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fi
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OLD_BACKUP_PATH=$(fn_find_backups | head -n 1)
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if [ "$OLD_BACKUP_PATH" == "" ]; then
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fn_log_error "No space left on device, and cannot get path to oldest backup to delete."
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exit 1
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fi
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fn_expire_backup "$OLD_BACKUP_PATH"
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# Resume backup
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continue
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fi
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if [ "$RSYNC_EXIT_CODE" != "0" ]; then
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fn_log_error "Exited with error code $RSYNC_EXIT_CODE"
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exit $RSYNC_EXIT_CODE
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fi
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rm -- "$INPROGRESS_FILE"
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# TODO: grep for "^rsync error:.*$" in log
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fn_log_info "Backup completed without errors."
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exit 0
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done
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