In-depth explanation of the usage of Linux chage command

Linux operating system is an open source operating system widely used in servers and personal computers. Some of these commands play an important role in system management and security, including the chage command. The chage command can be used to manage the password expiration policy of user accounts, the minimum password usage period, the maximum usage period, password expiration reminders, etc.

In this article, the advanced usage of the Linux chage command will be analyzed in detail, and specific code examples will be provided to help readers better understand and apply this command.

1. Basic usage of the chage command

In the Linux system, the chage command is used to modify the password expiration information of the user account. Its basic syntax is as follows:

chage [options] username

Among them, username is the username to be operated on. Commonly used options include:

• -M, --maxdays : Set the maximum password usage period.
• -m, --mindays : Set the minimum password usage period.
• -W, --warndays : The number of days to remind the user to change the password before the password expires.
• -I, --inactive : Set the number of days the account will be locked after inactivity.

2. Advanced usage of the chage command

2.1 View the password expiration information of the user account

Use the chage command to view the password expiration information of the user account. You can learn more The maximum usage period, minimum usage period, password expiration reminder, etc. of the password.

For example, view the password expiration information of user "testuser":

chage -l testuser

2.2 Set the maximum usage period of the password

Set the maximum usage period of the user password through the chage command , which can force users to change their passwords regularly to enhance system security.

For example, set the maximum password usage period of user "testuser" to 90 days:

chage -M 90 testuser

2.3 Set the minimum password usage period

Set the minimum password usage period. Prevent users from frequently changing their passwords and improve password security.

For example, set the minimum password usage period of user "testuser" to 7 days:

chage -m 7 testuser

2.4 Set password expiration reminder

By setting a password expiration reminder, you can remind the user in a timely manner Change your password to avoid account being locked due to password expiration.

For example, set the password expiration reminder for user "testuser" to 7 days:

chage -W 7 testuser

3. Actual case

The following uses an actual case to demonstrate the advanced usage of the chage command. .

We have a user account "testuser". We require the user to change the password once a month. The password is valid for 30 days. The user is reminded to change the password 7 days before the password expires. We can achieve this through the following steps:

# 设置密码最长使用期限为30天
chage -M 30 testuser

# 设置密码最短使用期限为0，允许用户立即修改密码
chage -m 0 testuser

# 设置密码过期提醒为7天
chage -W 7 testuser

Conclusion

Through this article’s advanced usage analysis of the Linux chage command, readers can better understand how to manage the password expiration policy of user accounts and improve the system security. I hope that the content provided in this article will be helpful to readers, and everyone is welcome to practice and explore more.

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