X-Git-Url: https://git.treefish.org/~alex/backmeupscotty.git/blobdiff_plain/1aa0158b6b4d4aaca7f413d76aec814a206a212b..4e6a9bb8cabd617d7368f55fa75a08bd99ca789c:/backmeupscotty?ds=sidebyside

diff --git a/backmeupscotty b/backmeupscotty
index ed41ae2..35ec754 100644
--- a/backmeupscotty
+++ b/backmeupscotty
@@ -18,22 +18,6 @@ function scottyerror {
     echo $(upperme): $@ >&2 
 }
 
-if [ $(pidof -x $(basename $0) | wc -w) -gt 2 ]; then 
-    scottyerror Another instance of $(basename $0) is already running!
-    exit 1
-fi
-
-while getopts "qn:" opt; do
-    case $opt in
-	q)
-	    exec > /dev/null
-	    ;;
-	n)
-	    BACKUP_RUNEVERYNTHDAY=$OPTARG
-	    ;;
-    esac
-done
-
 function grepbackups {
     ssh $REMOTE_HOST "ls $REMOTE_DIR" | grep -E '[0-9]+-[0-9]+'
 }
@@ -46,9 +30,8 @@ function isIncomplete {
     fi
 }
 
-function isIncompleteOrNthDay {
-    if isIncomplete || \
-	[ $(( ( $(date +%s) / (60*60*24) ) % $BACKUP_RUNEVERYNTHDAY )) -eq 0 ]; 
+function isNthDay {
+    if [ $(( ( $(date +%s) / (60*60*24) ) % $BACKUP_RUNEVERYNTHDAY )) -eq 0 ]; 
     then
 	return 0
     else
@@ -56,6 +39,20 @@ function isIncompleteOrNthDay {
     fi	
 }
 
+function latestTooOld {
+    for oldbackup in $(grepbackups); do
+	tstamp=$(echo $oldbackup | cut -d'-' -f1)
+	
+	if [ $(( $(date +%s) - $tstamp )) -lt \
+	    $(( $BACKUP_RUNEVERYNTHDAY*24*60*60 )) ]
+	then
+	    return 1
+	fi
+    done
+
+    return 0
+}
+
 function scottysync {
     timestamp=$(date +%s)
 
@@ -116,51 +113,95 @@ function scottysync {
     done
 }
 
-function prepare {
-    scottyinfo "Preparing for sync"
+function deleteLock {
+    if ! rmdir /tmp/$(basename $0).lock; then
+	scottyerror "Could not delete lockfile /tmp/$(basename $0).lock!"
+    fi
 }
 
-function cleanup_abrt {
-    scottyinfo "No cleanup_abrt function was defined."
+function prepare {
+    scottyinfo "Preparing for sync"
 }
 
-function _cleanup_abrt {
+function cleanup_abort {
     scottyerror "Caught exit signal! Cleaning up..."
-    cleanup_abrt
+
+    cleanup ABORT
+
     if [ $(jobs -p) ]; then
 	scottyerror TERMinating remaining child processes...
 	kill $(jobs -p)
     fi
+
+    deleteLock
+
     exit
 }
 
-function prepare {
-    scottyinfo "No prepare function was defined."
+function cleanup {
+    scottyinfo "No cleanup function was defined."
 }
 
-function _prepare {
-    prepare
+function prepare {
+    scottyinfo "No prepare function was defined."
 }
 
 function cleanup_normal {
-    scottyinfo "No cleanup_normal function was defined."
+    cleanup
+    deleteLock
 }
 
-function _cleanup_normal {
-    cleanup_normal
+function printhelp {
+    cat <<EOF
+Usage: $(basename $0) [OPTION]...
+
+Recognized options:
+  -q   Only output errors
+  -n   Run only on nth day
+  -h   Print out this help
+EOF
 }
 
 function backmeupscotty {
-    if ! isIncompleteOrNthDay; then
-	scottyinfo "This is not the nth day and no incomplete backup exists."
+    while getopts "qn:h" opt; do
+	case $opt in
+	    q)
+		exec > /dev/null
+		;;
+	    n)
+		BACKUP_RUNEVERYNTHDAY=$OPTARG
+		;;
+	    h)
+		printhelp
+                exit 0
+                ;;
+	esac
+    done
+
+    if isNthDay; then
+	scottyinfo "This is the nth day."
+    elif latestTooOld; then
+	scottyerror "The latest backup is too old."
+    else
+	scottyinfo "No backup has to be done. Exiting."
 	exit 0
     fi
 
-    trap _cleanup_abrt EXIT
+    scottyinfo "Performing backup."
 
-    _prepare
+    trap cleanup_abort EXIT
+
+    prepare
     scottysync
-    _cleanup_normal
 
-    trap - EXIT
+    trap cleanup_normal EXIT
+
+    exit 0
 }
+
+if ! mkdir /tmp/$(basename $0).lock; then
+    scottyerror "Another instance of $(basename $0) is still running!"
+    exit 1
+else
+    trap deleteLock EXIT
+fi