ok32 · July 27, 2016 19:03 · Jan 12, 2014 · Jan 12, 2014
diff --git a/rsync-incremental-backup.sh b/rsync-incremental-backup.sh
@@ -1,5 +1,12 @@
 #!/bin/bash
 
+# Rsync based file backup script, with hard-linking enabled.
+#
+# Runtime options:
+# -n - dry-run; do nothing, just display what is going to happen on a real run
+# -v - verbose output; print out what is being backed up
+#
+
 # set to your rsync location
 RSYNC_BIN="/usr/bin/rsync"
 # location of the files to back up (WITH a trailing slash)

diff --git a/rsync-incremental-backup.sh b/rsync-incremental-backup.sh
@@ -0,0 +1,67 @@
+#!/bin/bash
+
+# set to your rsync location
+RSYNC_BIN="/usr/bin/rsync"
+# location of the files to back up (WITH a trailing slash)
+SOURCE_DIR="/path/to/source_dir/"
+# target dir for backups (NO trailing slash)
+BACKUP_DIR="/path/to/backup_dir"
+# how many backups to keep
+KEEP_BACKUPS=7
+
+#
+# END OF CONFIGURATION
+#
+
+# takes command to execute as the first argument, and then
+# 1. Prints it if we're in verbose mode
+# 2. If we're in dry-run mode, as the second argument is nil - does nothing
+# 3. If we're not in dry-run mode - executes the command
+# 4. If we're in dry-run mode, but the 2nd argument is not nill - executes the commad
+#    (i.e. when it's constructed to dry-run by itself)
+function docmd {
+  if [ "$verbose" -eq 1 ]; then echo "--- $1"; fi
+  # if [ [ "$dry_run" -eq 0 ] -o [ -n $2 ] ]; then `$1`; fi
+  if [ "$dry_run" -eq 0 ] || [ -n "$2" ]; then $1; fi
+}
+
+# reset getopts
+OPTIND=1
+# set default values for configuration params
+dry_run=0
+verbose=0
+
+while getopts "vn" opt; do
+  case "$opt" in
+    v)  verbose=1;
+        ;;
+    n)  dry_run=1; verbose=1;
+        ;;
+  esac
+done
+
+# generate directory name that we'll be syncing into
+timestamp=`date +"%Y.%m.%d.%H.%M.%S"`
+sync_target="$BACKUP_DIR/$timestamp"
+
+# extra rsync options
+rsync_options=""
+# get a directory to link against, if any
+link_target=`ls -1 $BACKUP_DIR | tail -n1`
+# if we have a valid link directory - set it as an option for rsync
+if [ -n "$link_target" ]; then rsync_options="--link-dest=$BACKUP_DIR/$link_target"; fi
+# if we're in verbose mode - set it for rsync
+if [ "$verbose" -eq 1 ]; then rsync_options="$rsync_options -v"; fi
+# if we're in dry run mode - set it for rsync
+if [ "$dry_run" -eq 1 ]; then rsync_options="$rsync_options -n"; fi
+
+docmd "mkdir -p $sync_target"
+docmd "$RSYNC_BIN -a --delete $rsync_options $SOURCE_DIR $sync_target" 1
+
+backups_count=`ls -1 $BACKUP_DIR | wc -l`
+backups_to_remove=$(($backups_count-$KEEP_BACKUPS))
+if [ $backups_to_remove -gt 0 ]; then
+  for d in `ls -1 $BACKUP_DIR | head -n$backups_to_remove`; do
+    docmd "rm -rf $BACKUP_DIR/$d"
+  done
+fi