The image below contains an examination of the access mode displayed when the ls –l command is executed.
The file type - means this file is not a directory.
The file has the read permission and write permission bits set for the owner. The execute bit is not set for the owner.
The group has the read permission bit set, but not the write or execute bits.
The other permission bits are set so that read is set for everyone else (excluding the owner and the group), but write and execute are not.
This file has read and write permissions set for the owner, and no other permissions set.
This file has read and write permissions set for the user and the group, but only read permissions for everyone else.
This file is a directory, as indicated by the d in the first slot. This file has read, write, and execute permissions set for the owner, and execute-only permission set for the group and everyone else.
chmod [options] mode files
Change the access mode of one or more files. Only the owner of a file or a privileged user may change its mode. Create mode by concatenating the characters from who, opcode, and permission.
who is optional (if omitted, default is a); choose only one opcode.
-f, --quiet, --silent
Do not print error messages about files that cannot be changed.
Recursively descend through the directory, including subdirectories and symbolic links, setting the specified group ID as it proceeds.
The last of -H, -L, and -P takes effect when used with -R.