I ran ls -l on my centOS 6.10 on a specific file.
My question is what is the meaning of this dot(.) before 1?
-rw-r--r--. 1 root root 575 Oct 23
It means that the file has an SELinux context. Use ls -Z to see the actual SElinux context values. It's documented on the "info" file for GNU Coreutils: What-information-is-listed.
The relevant quote:
Following the file mode bits is a single character that specifies
whether an alternate access method such as an access control list
applies to the file. When the character following the file mode
bits is a space, there is no alternate access method. When it is a
printing character, then there is such a method.
GNU ‘ls’ uses a ‘.’ character to indicate a file with a security
context, but no other alternate access method.
A file with any other combination of alternate access methods is
marked with a ‘+’ character.
Follow the link for more details