I'm trying to write a script to start multiple tomcat instances on a web server. Each app directory is owned by a separate user, for segregation. In order to start each properly, I need to be able to write something to read the owner of the folder, so I can sudo as that user to start/stop it properly. The issue is, I cna't find an easy way to read the owner of the folder, in the script.

You could always use the stat command to retrieve the info. It should print off the UID/Username and GID/Groupname on the Access line. Just use a little sed/awk/cut magic to pull what you need.

Example output:

[user@localhost home]# stat /home
File: `/home'
Size: 4096 Blocks: 16 IO Block: 4096 directory
Device: 901h/2305d Inode: 7503873 Links: 28
Access: (0755/drwxr-xr-x) Uid: ( 0/ root) Gid: ( 0/ root)
Access: 2007-12-05 20:07:24.000000000 +0000
Modify: 2007-10-26 16:15:10.000000000 +0000
Change: 2007-10-26 16:15:10.000000000 +0000

Assuming there is no real down side to trying to start tomcat for a user that does not have a directory .AND. you can login as root then:

read the /etc/password file for user id's > distribution minimum ie 1000; then form that list try and su to that user and issue your start command.