Turn: http://wangshuxing123-126-com.iteye.com/blog/695653
Chmod is a command for setting file permissions in Linux. The following numbers indicate permissions of different users or user groups.
Generally, there are three numbers:
The first number indicates the permission of the file owner.
The second number indicates the permissions of other users in the same user group as the file owner.
The third digit indicates the permissions of other user groups.
There are three types of permissions: Read (r = 4), write (W = 2), and execute (x = 1)
. In combination, there are also readable executable (RX = 5 = 4 + 1) and readable writable (RW = 6 = 4 + 2), readable and writable (rwx = 7 = 4 + 2 + 1 ).
Therefore, chmod 755 sets the user's permissions:
1. The file owner is readable and writable and executable -- 7
2. Other users in the same user group as the file owner can read and execute-5
3. Other user groups can be read and executed-5