using lockfiles in shell scripts (BASH) If you want to be 100% sure that only 1 process accesses a resource at the same time, you can use the command "lockfile". Lockfile creates a semaphore file [ ... ]

Let's assume that you have a directory "test" containing the following files:  [root@blackmod test]# ls -la
total 8
drwxr-xr-x.  2 root root 4096 2010-03-10 06:11 .
dr-xr-x---. 11 root root 4096 20 [ ... ]