[SOLVED] What is the s protection bit in a file?

[Griff]

For example when you run:

ls -l /usr/bin/passwd
to view the protection bits of passwd there is an s in the owner permission area. What is that? I thought there was only r, w, or x?
Here it is:

-rwsr-xr-x 1 root root 29104 2006-12-19 15:35 /usr/bin/passwd

[aks44]

When in the first rwx group (the one which corresponds to the owner user), S is the setuid (http://en.wikipedia.org/wiki/Setuid) bit. In the second rwx group (owner group) it is the setgid bit.

When the file has both x and S, s is displayed. If the file doesn't have x, S is displayed.

[Griff]

Ah! Thank you! I googled and searched but couldn't find anything relating to this. :)