$ ls -l filename
filename specifies the file or directory.
In the output, a plus sign (+) to the right of the mode field indicates that the file has an ACL.
Unless you have added ACL entries for additional users or groups on a file, a file is considered to be a “trivial” ACL and the plus sign (+) will not display.
The following example shows that the ch1.doc file has an ACL, because the listing has a plus sign (+) to the right of the mode field.
$ ls -l ch1.doc -rwxr-----+ 1 nathan sysadmin 167 Nov 11 11:13 ch1.doc