Linux中的/etc/gshadow中密碼的作用

轉自：http://linux.die.net/man/5/gshadowencrypted password

Refer to crypt(3) for details on how this string is interpreted.

If the password field contains some string that is not a valid result of crypt(3), for instance ! or *, users will not be able to use a unix password to access the group (but group members do not need the password).

The password is used when an user who is not a member of the group wants to gain the permissions of this group。

This field may be empty, in which case only the group members can gain the group permissions.

A password field which starts with a exclamation mark means that the password is locked. The remaining characters on the line represent the password field before the password was locked.

This password supersedes any password specified in /etc/group.