passwd(5) — Linux manual page

NAME | DESCRIPTION | FILES | SEE ALSO | COLOPHON

PASSWD(5)            File Formats and Configuration            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, also known as the gecos field, is used by
       various system utilities, such as finger(1). The use of an
       ampersand here will be replaced by the capitalised login name
       when the field is used or displayed by such system utilities.

       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
       [email protected].  This page was obtained
       from the project's upstream Git repository
       ⟨https://github.com/shadow-maint/shadow⟩ on 2023-12-22.  (At that
       time, the date of the most recent commit that was found in the
       repository was 2023-12-15.)  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
       [email protected]

shadow-utils 4.11.1            12/22/2023                      PASSWD(5)