bin/srsync-incremental: use a unique target directory

This replaces the "current" target directory. In the past when a backup
failed the "current" directory remained causing all future backups to
fail as well.

diff --git a/bin/srsync-incremental b/bin/srsync-incremental
index 9d800b9cd85b7165069200f0f8b5e776e01551d1..685505884b871b1a9795b4cac06e63893c0f9275 100755 (executable)
--- a/bin/srsync-incremental
+++ b/bin/srsync-incremental
@@ -5,7 +5,7 @@
 # Thanks to http://www.sanitarium.net/golug/rsync_backups_2010.html for the
 # idea.
 
-# Copyright (C) 2011-2014  Simon Ruderich
+# Copyright (C) 2011-2016  Simon Ruderich
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -34,32 +34,28 @@ fi
 cd "$1"
 shift
 
-# Get absolute path to last backup directory.
+# Get path to last backup directory.
 dest=./
 for x in backup-*; do
     test -d "$x" || continue
     dest="../$x" # relative to destination directory
 done
 
-target=backup-`date '+%Y-%m-%d-%H-%M-%S'`
+target="backup-$(date '+%Y-%m-%d-%H-%M-%S')"
+target_tmp="partial-$target"
 
-if test -d current; then
-    echo "Target directory 'current' already exists, aborting." >&2
-    exit 1
-fi
-
-mkdir current
+mkdir "$target_tmp"
 rsync \
     --verbose --itemize-changes --human-readable \
     --archive --hard-links --sparse --numeric-ids --one-file-system \
     --link-dest="$dest" \
-    "$@" current \
+    "$@" "$target_tmp" \
 || {
-    # Try to remove "current" without changing the exit code. In case the
-    # connection failed without transferring any files, we want the next
-    # backup to be able to run.
+    # Try to remove the target directory without changing the exit code. In
+    # case the connection failed without transferring any files, we want to
+    # remove the empty directory.
     code=$?
-    rmdir current 2>/dev/null || true
+    rmdir "$target_tmp" 2>/dev/null || true
     exit $code
 }
-mv current "$target"
+mv "$target_tmp" "$target"