Possible Duplicate:What Unix commands can be used as a semaphore/lock? I have read many similar post and the solution seems to be to use flock. flock does not exist on my system and I don't have rights to add it.  References:A BashFAQ link provided in a comment in how-to-make-sure-only-one-instance-of-a-bash-script-runs talks about using flock
How do I ensure that only one instance of my ksh script runs on Solaris using NFS?
solaris;ksh;nfs;lock