What does the trailing "+" mean in file permission bits in Linux?

Question

I used ls -a to list a file and got the following information:

sqyang@intel4-88: ls -a 123 
-rwxr-xr-x+ 1 root lsf 16845584 Nov 25 21:38 123*

The file permission part is -rwxr-xr-x+. What does the + mean at the end?

Answer 1

The "+" indicates that there is an ACL (Access Control List) entry associated with the file. I don't know about Linux, but ACLs are used on Solaris too. See the manual pages for "getfacl" and "setfacl".

Source

Answer 2

http://linux.about.com/library/cmd/blcmdl5_acl.htm

For files that have a default ACL or an access ACL that contains more than the three required ACL entries, the ls(1) utility in the long form produced by ls -l displays a plus sign ( + after the permission string.