Extract new backup action out of archive.

actions/archive

@@ -16,7 +16,7 @@
 #   under the terms of the GNU General Public License.
 #   See http://www.gnu.org/copyleft/gpl.txt
 #
-# @(#)archive	002	(19-Mar-2012)	todo.txt-cli-ex
+# @(#)archive	003	(13-Apr-2012)	todo.txt-cli-ex
 ###############################################################################
 
 action=$1
@@ -104,18 +104,10 @@ processItems 'x' "$DONE_FILE" 'archived' "$items" "$@"
 processItems 'X' "$TRASH_FILE" 'trashed' "$items" "$@"
 
 
-if [ $# -eq 0 ]; then
+if [ $# -eq 0 -a -x "$TODO_ACTIONS_DIR/backup" ]; then
     # This is a complete, regular archive.
     # Use this occasion to make a backup.
-    if type -P writebackup >/dev/null; then
-        readonly TODO_BACKUPDIR="${TODO_DIR}.backup/"
-        if [ -d "$TODO_BACKUPDIR" ]; then
-            cp -f "$TODO_FILE" "${TODO_BACKUPDIR}/todo.txt"
-            writebackup "${TODO_BACKUPDIR}/todo.txt"
-        else
-            writebackup "$TODO_FILE"
-        fi
-    fi
+    "$TODO_FULL_SH" backup
 fi
 
 # Defragment blank lines.

actions/backup

@@ -0,0 +1,56 @@
+#!/bin/bash
+###############################################################################
+##
+# FILE:         backup
+# PRODUCT:      todo.txt-cli-ex
+# AUTHOR:       Ingo Karkat <ingo@karkat.de>
+# DATE CREATED: 13-Apr-2012
+#
+###############################################################################
+# CONTENTS:
+#
+# REMARKS:
+#
+# COPYRIGHT: (C) 2012 Ingo Karkat
+#   This program is free software; you can redistribute it and/or modify it
+#   under the terms of the GNU General Public License.
+#   See http://www.gnu.org/copyleft/gpl.txt
+#
+# @(#)backup	001	13-Apr-2012	todo.txt-cli-ex
+###############################################################################
+
+action=$1
+shift
+
+[ "$action" = "usage" ] && {
+    echo "    $(basename $0)"
+    echo "      Writes a backup copy of todo.txt."
+    echo ""
+    exit
+}
+
+# Configuration to place the backups into a different directory.
+: ${TODOTXT_BACKUP_DIR="${TODO_DIR}.backup"}
+# Use a custom backup script if it exists, fall back on a simple copy to a
+# timestamp; do nothing when the command is "none".
+: ${TODOTXT_BACKUP_COMMAND:=writebackup}
+
+
+if [ "$TODOTXT_BACKUP_COMMAND" = 'none' ]; then
+    # Skip backup.
+    :
+elif type -P "$TODOTXT_BACKUP_COMMAND" >/dev/null; then
+    if [ -d "${TODOTXT_BACKUP_DIR%/}" ]; then
+        "$TODOTXT_BACKUP_COMMAND" -d "${TODOTXT_BACKUP_DIR%/}" "$TODO_FILE"
+    else
+        "$TODOTXT_BACKUP_COMMAND" "$TODO_FILE"
+    fi
+else
+    readonly timestamp=$(date +%F_%H%M%S)
+    readonly backupFilename="todo_${timestamp}.bak"
+    if [ -d "${TODOTXT_BACKUP_DIR%/}" ]; then
+        cp "$TODO_FILE" "${TODOTXT_BACKUP_DIR%/}/${backupFilename}" && echo "Backed up to ${TODOTXT_BACKUP_DIR%/}/${backupFilename}"
+    else
+        cp "$TODO_FILE" "$backupFilename" && echo "Backed up to ${backupFilename}"
+    fi
+fi