Shell Programming and Scripting

Hello,

I would like to make a script, ideally in perl since I am most familair with it, that does the following:

automatically starts up at 9 pm, searches through a specified directory for any new files, finds those new files and starts to run them through a pipeline. I have most of it worked out, but here are somethings I am not sure how to do:

1) How do I make it start automatically at 9pm? I could put it sleep and tell it to wait for 9pm, but the truth is that sometimes, when a lot of new data comes, it realistically can take 24 hours or more to run an initial instance of script. I feel it might get confused if I just band-aid it with a sleep command, however if that's the only solution then that's what I will have to do.

2) How do I get time stamps for the files in the directory?

Ideally I don't want to use to too many non-standard modules, because it can make it less portable since other users will also have to download all those modules to use my little scripts (assuming it works out, other people here would like to use it...).

Thanks!

What OS are you running? Windows? Unix?

If you are running Linux or Unix look into crontab to automate the program to run at 9PM.

Thanks,

I am running it on linux!

You said it can take more than 24 hours to run?

If you start it from cron, does it matter that they old script could still be running? If so, you'll need to put some locking mechanism in to prevent that. Not hard, but could matter.