how do i lock a ksh shell script

[ndedhia1]

Hi,
I have a ksh shell script that accesses databases to drop and create tables and the script also creates text files.
This shell script is accessed thru a java application that i would like to turn multi-user, but the only way that i can do that is if I can figure out a way to lock the shell script so that only 1 user can access it at a time.
If 2 or more users access it, then bad things happen when 2 users and trying to drop and create the same database at the same time, or trying to create the same text file at the same time.

I would also like for the user to wait till the shell script is unlocked, instead of just passing over it or ending the application.

please help!!

thanks!!

[sicarie]

I'm not sure how deep into the working of Linux you want to get, but you could just create a hidden file that is something like a system command (I think - a call that lets you run command-line commands inside a program) like 'touch .programname.lo ck', and have your script check to see if it exists or not before executing (and when it's done, remove the file through 'rm .programname.lo ck'. I know this functionality exists in Linux, however I don't know the calls to set it up through Java, but I'm sure a Google search would be able to help with that.

On the wait - how do you want your program to behave? Do you want it to keep trying (keep looking for the lock file) every 5/10/20 seconds? Or do you want to inform the user, and suggest they run the program again later?

I'd recommend coming up with the specific functionality you want - that will make it easier to code.