backup-script-wrapper: Check for PID file ("lock file")

Check for the existence of the PID and abort if if exists file before
redirecting the output to the log file, to not garble it when an other
instance is still running.

diff --git a/bin/backup-script-wrapper b/bin/backup-script-wrapper
index bb9009de65a9b9132ad5921cb6d9f71c6869b233..32a15a66bf40eb7fac8732c2908b7b42a77eac6f 100755 (executable)
--- a/bin/backup-script-wrapper
+++ b/bin/backup-script-wrapper
@@ -25,12 +25,23 @@ NAME="backup-script"
 DELIMITER="- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -"
 HOST=`hostname -f`
 LOGFILE="/var/log/$NAME.log"
+PIDFILE="/var/run/$NAME.pid"
 SUBJECT="$NAME results"
 TMP=`mktemp /tmp/$NAME.XXXXXXXX` || exit 1
 
 PATH="$PATH:/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin"
 export PATH
 
+# check PID file ("lock file")
+if [ -e "$PIDFILE" ]; then
+       echo "Lockfile \"$PIDFILE\" already exists."
+       echo "Is an other instance still running?"
+       echo
+       echo -n "Aborted: "; date
+       echo
+       exit 4
+fi
+
 exec >"$TMP" 2>&1
 
 echo "$NAME Report"