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Linux in a Nutshell

This directory of Linux commands is from Linux in a Nutshell, 5th Edition.

Click on any of the 687 commands below to get a description and list of available options. All links in the command summaries point to the online version of the book on Safari Bookshelf.

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chage [options] user

Change information about user password expirations. If run without any option flags, chage will prompt for values to be entered; you may also use option flags to change or view information.



This flag is used without any others and causes chage to display the current password expiration attributes for the user.

-m mindays

Minimum number of days between password changes. Default is zero, meaning that the user may change the password at any time.

-M maxdays

Maximum number of days between password changes.

-d lastday

Date of last password change. This may be expressed as a date in YYYY-MM-DD format, or as the number of days between January 1, 1970 and the last password change.

-I inactive-days

If a password expires and the user does not log in for this number of days, the account will be locked and the user must contact a system administrator before logging in. Set to 0 to disable the feature.

-E expiredate

Set the date when the account will be locked. This is not a date for password expiration, but for account expiration. It may be expressed as a YYYY-MM-DD date or as a number of days since January 1, 1970.

-W warning

The number of days before password expiration that a user will be warned to change passwords.