passwd命令修改密码

Linux passwd command changes a user’s password. A user can only change his/her own password but the root/superuser may change any user’s password.

Linux passwd命令更改用户密码。 用户只能更改自己的密码，但root / superuser可以更改任何用户的密码。

Let’s look at the Linux man page to understand the usage of this command. This is done by typing in the following command:

让我们看一下Linux手册页，以了解此命令的用法。 通过键入以下命令来完成此操作：

The traditional method of storing passwords in a UNIX based system involved storing the information in /etc/passwd file.

在基于UNIX的系统中存储密码的传统方法包括将信息存储在/ etc / passwd文件中。

This file, however, was accessed by many programs and hence posed a security risk.

但是，该文件已被许多程序访问，因此存在安全风险。

Nowadays, /etc/passwd file only contains essential user info required at login and authentication.

如今， /etc/passwd文件仅包含登录和身份验证所需的基本用户信息。

The actual encrypted version of the password is stored in a separate file – /etc/shadow. This file can only be accessed by the root user.

密码的实际加密版本存储在单独的文件/etc/shadow 。 该文件只能由root用户访问。

passwd file contents

Each line of the file contains general user information about a certain program or user. The fields are separated by :. These field are as follow:

passwd文件内容

文件的每一行都包含有关某个程序或用户的一般用户信息。 这些字段用:分隔。 这些字段如下：