bin/srsync-incremental: fix initial backup

[config/dotfiles.git] / bin / srsync-incremental

diff --git a/bin/srsync-incremental b/bin/srsync-incremental
index 9ebf41949518ba541d2ee6cdedce24b38b2a44d0..9d800b9cd85b7165069200f0f8b5e776e01551d1 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) 2011-2013  Simon Ruderich
+# Copyright (C) 2011-2014  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
@@ -21,6 +21,8 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 
+set -eu
+
 if test "$#" -lt 2; then
     echo "Usage: $0 <backups-directory> <arguments to rsync>" >&2
     echo
@@ -28,14 +30,16 @@ if test "$#" -lt 2; then
     exit 2
 fi
 
-cd "$1" || exit 1
+
+cd "$1"
 shift
 
-dest=`echo backup-*`
-if test "x$dest" != 'xbackup-*'; then
-    # -F and grep is used to list only directories, zsh's *(/) would be great.
-    dest="`pwd`/`ls -1dF backup-* | grep / | tail -n1`"
-fi
+# Get absolute path to last backup directory.
+dest=./
+for x in backup-*; do
+    test -d "$x" || continue
+    dest="../$x" # relative to destination directory
+done
 
 target=backup-`date '+%Y-%m-%d-%H-%M-%S'`
 
@@ -47,7 +51,15 @@ fi
 mkdir current
 rsync \
     --verbose --itemize-changes --human-readable \
-    --archive --hard-links --numeric-ids --one-file-system \
+    --archive --hard-links --sparse --numeric-ids --one-file-system \
     --link-dest="$dest" \
     "$@" current \
-&& mv current "$target"
+|| {
+    # Try to remove "current" without changing the exit code. In case the
+    # connection failed without transferring any files, we want the next
+    # backup to be able to run.
+    code=$?
+    rmdir current 2>/dev/null || true
+    exit $code
+}
+mv current "$target"