vrsync

#! /bin/bash
# Like rsync but versioned.  And by versioned, I mean:
# each time vrsync is run, it makes a copy of the source argument into the
# destination, named for the current date, and all files which have not
# changed since the last time vrsync was run are merely hard links to those
# previously seen files.  And, don't keep old copies forever, just for some
# 60 days, but the operator of this script can override that.
#
# vrsync isn't exactly like rsync, though:
#
# Usage: vrsync [--max-age N] [--knock host]
#               rsync://path/to/remote/directory/
#               /local-directory/
# where
# --max-age N  :: change the default 60 days for the max time to keep old dirs
# --knock host :: execute "bink/knock host"

maxage=60

opts=
knock=
verbose=
while [ $# -gt 0 ]; do
    case $1 in
	--knock)
	    shift
	    knock=$1
	    ;;
	--max-age)
	    shift
	    maxage=$1
	    ;;
	-v) verbose=$1
	    opts="$opts $1"
	    ;;
	-*) opts="$opts $1" ;;
	*) break ;;
    esac
    shift
done

from="$1"
to="$2"

[ -d "$to" ] || mkdir "$to"

function d {
#For debugging, uncomment this:
    #echo "+ $*"
    "$@"
}

# remove expired directories
for dir in `find "$to" -maxdepth 1 -type d -mtime +$maxage`; do
    #echo "NOTE: removing expired directory: $dir"
    d rm -fr "$dir"
done

mostrecent=`(cd "$to"; /bin/ls -r) | grep '^[0-9]' | head -1`
today=`date +%Y.%m.%d-%H:%M:%S`

if [ -z "$mostrecent" ]; then
    echo No older mirror to rotate.  Starting fresh.
elif [ "$(uname -s)" = "Darwin" ]; then
    ##### Mac OS doesn't have "cp -l"... so use rsync
    #echo most recent is $mostrecent.  Making links.
    d rsync -qa --link-dest=../$mostrecent $to/$mostrecent/ $to/$today
else
    #echo most recent is $mostrecent.  Making links.
    d cp -al $to/$mostrecent $to/$today
fi

[ "$knock" ] && knock -q $knock

d myrsync $opts "$from" "$to/$today"

# Note: rsync will set the modification time of the destination
# directory to the modification time of the source directory so we touch
# it here so that it reflects the time of the backup.
touch "$to/$today"

# make a `latest' link
rm -f "$to/latest"
ln -s "$today" "$to/latest"