What character in the /etc/shadow password field indicates a disabled account?

What character in the /etc/shadow password field indicates a disabled account?

• A. Asterisk
• B. Question mark
• C. Plus sign
• D. Exclamation point

Answer: (D)

Special markers at the start of the password field in /etc/shadow indicate account status. An exclamation point disables the account by making the stored password unusable for authentication, so login attempts always fail even with the correct password. This is the standard signal that a account is locked or disabled in many Linux systems, which is why it’s the best answer here. Some systems may also use an asterisk for a similar effect, but the exclamation point is the explicit marker tied to disabling the account. The other symbols don’t specifically denote a disabled account in the shadow file. If you ever need to re-enable it, you would unlock the account with the appropriate tool (for example, unlocking the shadow entry) so that a valid password can be used again.

Special markers at the start of the password field in /etc/shadow indicate account status. An exclamation point disables the account by making the stored password unusable for authentication, so login attempts always fail even with the correct password. This is the standard signal that a account is locked or disabled in many Linux systems, which is why it’s the best answer here. Some systems may also use an asterisk for a similar effect, but the exclamation point is the explicit marker tied to disabling the account. The other symbols don’t specifically denote a disabled account in the shadow file. If you ever need to re-enable it, you would unlock the account with the appropriate tool (for example, unlocking the shadow entry) so that a valid password can be used again.