What does the left angle bracket after a while loop mean in bash?

Question

The following is from /etc/init.d/functions on RHEL. I\'m trying to figure out what the __pids_var_run() function does when I came across this while loop.

Answer 1

I see that this quesiton is already answered (I cannot comment because I did a bounty), but I think you should check out this site when you get a chance:

http://mywiki.wooledge.org/BashFAQ/001

This guy (or gal) really dives in to proper and improper syntax with examples.