chage

Overview

The chage command changes user password expiry information. It modifies the number of days between password changes and checks password aging.

Syntax

chage [options] username

Common Options

Option Description
-d days Last change
-E date Account expiry
-I days Inactive days
-l List aging info
-m days Minimum days
-M days Maximum days
-W days Warning days
--help Show help
--version Show version

Configuration Files

File Description
/etc/shadow Password data
/etc/login.defs Login defaults
/etc/pam.d/system-auth PAM config
/etc/security/limits.conf System limits

Key Use Cases

  1. Password aging
  2. Account expiry
  3. Security policy
  4. User management
  5. Access control

Examples with Explanations

Example 1: List Info

chage -l username

Show aging info

Example 2: Set Expiry

chage -E 2024-12-31 username

Set account expiry

Example 3: Force Change

chage -d 0 username

Force password change

Common Usage Patterns

  1. View settings:

    chage -l user

  2. Set maximum:

    chage -M 90 user

  3. Set warning:

    chage -W 7 user

Security Considerations

  1. Password policy
  2. Account access
  3. Expiry control
  4. Security compliance
  5. User notification

Additional Resources

Best Practices

  1. Regular updates
  2. Policy compliance
  3. User notification
  4. Documentation
  5. Security audit

Password Management

  1. Aging control
  2. Expiry settings
  3. Policy enforcement
  4. Access management
  5. Security control

Troubleshooting

  1. Expiry issues
  2. Policy conflicts
  3. Access problems
  4. System errors
  5. User complaints

Common Issues

  1. Expired passwords
  2. Account lockouts
  3. Policy violations
  4. System conflicts
  5. User confusion