Shell Programming and Scripting

Hi All
I am not an expert at shell programming. But in the process of learning. But I have a requirement it goes as follows :

Requirement 1:
I have a series of files that keep comming on a unix folder every hour. The files names are different. As soon as a file arrives in this folder I will like to kick off a shell script that will validate the file name and call the respective proceedure or a load script to load this file to a database.

Requirement 2:
From a windows server I will like to perform a secured ftp on to a unix folder every hour. There will be 4 parallel sequences of files that would be dumped on to the windows server and will have a corresponding completed trigger file for each sequence.

thanks for reading the above.
Can you please guide me where to start this from and if there are any scripts that i can go thro that will be very useful.

THANKS A TON!! :-)

Regards
Beginner...

when you said files keep coming every hour. So its like they just come all in one go and then for 1 hour .. there is nothing coming in the folder?

the the complete picture is as follows.
There are hourly extract files which are dumped on to a windows shared folder. These set of files have four streams and one trigger (complete) file associated with each stream. Streams come in parallel and nearly the same time (within 5 minuit) window. these have to be "pulled" on to a linux or aix server every hour (so u are right, they come in one go and after 1 hour they arrive again)and as soon as a file lands on unix the corresponding database load module has to trigger (this is to ensure that we load files parallely and save time for a near real time load).
I need some starting points, and some key design aspects that I might have to consider to make the entire solution robust and scaleable.

Your script (unless you go VERY OS specific) will poll the receiving directory looking for a time change (i.e. it has been updated). If you have a good shell "test" available you'll be able to see if a "file" (your dir) is newer than another file (your last timestamp from the last change). Of course, that doesn't tell you if it changed... but for a large directory if the files linger, checking for time change before doing a potentially long check of the actual directory contents is wise (?).

That timestamp file COULD be the last known list of files in some sorted order... thus if the timestamp is now older, use the list found there to compare with the new list of files in the directory and identify the changed files.... then move that new filelist as the timestamp file (avoid modifying the file or time on the file of course)... etc...