passwd(5) — Linux manual page

NAME | DESCRIPTION | FILES | SEE ALSO | COLOPHON

PASSWD(5)               File Formats and Conversions               PASSWD(5)

NAME top

       passwd - the password file

DESCRIPTION top

       /etc/passwd contains one line for each user account, with seven
       fields delimited by colons (“:”). These fields are:

       ·   login name

       ·   optional encrypted password

       ·   numerical user ID

       ·   numerical group ID

       ·   user name or comment field

       ·   user home directory

       ·   optional user command interpreter

       If the password field is a lower-case “x”, then the encrypted
       password is actually stored in the shadow(5) file instead; there must
       be a corresponding line in the /etc/shadow file, or else the user
       account is invalid.

       The encrypted password field may be empty, in which case no password
       is required to authenticate as the specified login name. However,
       some applications which read the /etc/passwd file may decide not to
       permit any access at all if the password field is blank.

       A password field which starts with an exclamation mark means that the
       password is locked. The remaining characters on the line represent
       the password field before the password was locked.

       Refer to crypt(3) for details on how this string is interpreted.

       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).

       The comment field is used by various system utilities, such as
       finger(1).

       The home directory field provides the name of the initial working
       directory. The login program uses this information to set the value
       of the $HOME environmental variable.

       The command interpreter field provides the name of the user's command
       language interpreter, or the name of the initial program to execute.
       The login program uses this information to set the value of the
       $SHELL environmental variable. If this field is empty, it defaults to
       the value /bin/sh.

FILES top

       /etc/passwd
           User account information.

       /etc/shadow
           optional encrypted password file

       /etc/passwd-
           Backup file for /etc/passwd.

           Note that this file is used by the tools of the shadow toolsuite,
           but not by all user and password management tools.

SEE ALSO top

       crypt(3), getent(1), getpwnam(3), login(1), passwd(1), pwck(8),
       pwconv(8), pwunconv(8), shadow(5), su(1), sulogin(8).

COLOPHON top

       This page is part of the shadow-utils (utilities for managing
       accounts and shadow password files) project.  Information about the
       project can be found at ⟨https://github.com/shadow-maint/shadow⟩.  If
       you have a bug report for this manual page, send it to
       pkg-shadow-devel@alioth-lists.debian.net.  This page was obtained
       from the project's upstream Git repository
       ⟨https://github.com/shadow-maint/shadow⟩ on 2020-08-13.  (At that
       time, the date of the most recent commit that was found in the repos‐
       itory was 2020-08-13.)  If you discover any rendering problems in
       this HTML version of the page, or you believe there is a better or
       more up-to-date source for the page, or you have corrections or
       improvements to the information in this COLOPHON (which is not part
       of the original manual page), send a mail to man-pages@man7.org

shadow-utils 4.8.1               08/13/2020                        PASSWD(5)