Move to shell/ in preparation for merge into new dotfiles repository

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

diff --git a/shell/bin/srsync-incremental b/shell/bin/srsync-incremental
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+#!/bin/sh
+
+# Perform incremental backups using rsync and hardlinks.
+#
+# Thanks to http://www.sanitarium.net/golug/rsync_backups_2010.html for the
+# idea.
+
+# Copyright (C) 2011-2017  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
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# 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
+    echo "Note: The target directory is the _first_ argument!" >&2
+    exit 2
+fi
+
+
+cd "$1"
+shift
+
+# Get path to last backup directory.
+dest=./
+for x in backup-*; do
+    test -d "$x" || continue
+    dest="../$x" # relative to destination directory
+done
+
+target="backup-$(date '+%Y-%m-%d-%H-%M-%S')"
+target_tmp="partial-$target"
+
+mkdir "$target_tmp"
+rsync \
+    --verbose --itemize-changes --human-readable \
+    --archive --acls --xattrs --hard-links --sparse --numeric-ids \
+    --one-file-system \
+    --link-dest="$dest" \
+    "$@" "$target_tmp" \
+|| {
+    # Try to remove the target directory without changing the exit code. In
+    # case the connection failed without transferring any files, we want to
+    # remove the empty directory.
+    code=$?
+    rmdir "$target_tmp" 2>/dev/null || true
+    exit $code
+}
+# --dry-run (-n) creates an empty directory. Remove it to prevent using it for
+# further incremental backups (which would do a full backup).
+rmdir "$target_tmp" 2>/dev/null && exit 0 || true
+
+mv "$target_tmp" "$target"