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Santosa Sandy
Asked: 2014-01-24 07:40:06 +0800 CST

Quit from the middle of password setting process

  • 772

I try to check whether my root has password or not.

I run this command;

sudo passwd root

Later on it responses as;

Enter new UNIX password:

Based on that response, I have an indication that my root has no password. Therefore I want to quit from the command process.

How can I do that, please?

password

3 Answers

  1. Best Answer

    To view if your root has a password set use:

    sudo passwd -S root

    This will print out a:

    1. P in the second column if it has a password;
    2. L in the second column if it has a locked password (a password which is impossible to type in) and L is the default on Ubuntu;
    3. NP if it has no password.

    To get out of the new password dialog just type wrong passwords: Type a new password and when asked for confirmation for this new password type a different password. The passwords will not match and the program exits with an appropriate error message.

    (You can't use signals to quit, because passwd ignores every signal. Except SIGKILL should work, but it is unnecessary and maybe insecure to use here.)

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  2. Based on that response, I have an indication that my root has no password.

    No. Since your admin is the one changing the password the current password is not asked. Otherwise changing a password for an account would require asking the user for his/her password.

    Check /etc/shadow. Those files tell you if a user has a password and what encryption is used.

    The colums in /etc/shadow are :-seperated and indicate:

    • User name : It is your login name
    • Password: It your encrypted password. The password should be minimum 6-8 characters long including special characters/digits
    • Last password change (lastchanged): Days since Jan 1, 1970 that password was last changed
    • Minimum: The minimum number of days required between password changes i.e. the number of days left before the user is allowed to change his/her password
    • Maximum: The maximum number of days the password is valid (after that user is forced to change his/her password)
    • Warn : The number of days before password is to expire that user is warned that his/her password must be changed
    • Inactive : The number of days after password expires that account is disabled
    • Expire : days since Jan 1, 1970 that account is disabled i.e. an absolute date specifying when the login may no longer be used

    ===

    See: http://linux.die.net/man/5/shadow If the password field contains some string that is not a valid result of crypt(3), for instance ! or *, the user will not be able to use a unix password to log in (but the user may log in the system by other means). ... A password field which starts with a exclamation mark means that the password is locked. The remaining characters on the line represent the password field before the password was locked.

    ===

    Therefore I want to quit from the command process.

    control-x

    It will show something like "[1]+ Stopped sudo passwd"

    • 1

  3. To escape a command running in a bash terminal use Ctrl-C.

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