[CentOS] Any one have a good example...

Tue Aug 29 20:55:27 UTC 2006
Matthew Miller <mattdm at mattdm.org>

On Tue, Aug 29, 2006 at 11:13:43AM -0700, Scott Silva wrote:
> ...of a shell script for rsync that won't start again if it is already 
> running? I thought of using a lock file, but what if it is killed mid
> script or bombs?

1. Use a directory for locking instead of a file, because testing for
   existence and creating the directory is an atomic operation.

2. Use trap to remove the lockdir

so basically:

if ! mkdir $LOCKDIR ; then
    echo "Lockdir exists; aborting."
    exit 1
fi
trap "rmdir $LOCKDIR; echo 'mirror script exiting'" EXIT TERM INT QUIT

rsync $RSYNCOPTS $REMOTE $LOCAL



-- 
Matthew Miller           mattdm at mattdm.org          <http://mattdm.org/>
Boston University Linux      ------>              <http://linux.bu.edu/>