PASSWD(4)                                               PASSWD(4)



     NAME
          passwd - password file

     SYNOPSIS
          /etc/passwd

     DESCRIPTION
          The passwd file contains for each user the following
          information:

          name      User's login name - contains no upper case
                    characters and must not be greater than eight
                    characters long.

          password  encrypted password

          numerical user ID
                    This is the user's ID in the system and it must be
                    unique.

          numerical group ID
                    This is the number of the group that the user
                    belongs to.

          user's real name
                    In some versions of UNIX, this field also contains
                    the user's office, extension, home phone, and so
                    on.  For historical reasons this field is called
                    the GCOS field.

          initial working directory
                    The directory that the user is positioned in when
                    they log in - this is known as the `home'
                    directory.

          shell     program to use as Shell when the user logs in.

          The user's real name field may contain `&', meaning insert
          the login name.

          The password file is an ASCII file.  Each field within each
          user's entry is separated from the next by a colon.  Each
          user is separated from the next by a new-line.  If the
          password field is null, no password is demanded; if the
          Shell field is null, /bin/sh is used.

          The passwd file can also have a line beginning with a plus
          (+), which means to incorporate entries from the Yellow
          Pages.  There are three styles of + entries:  all by itself,
          + means to insert the entire contents of the Yellow Pages
          password file at that point; +name means to insert the entry
          (if any) for name from the Yellow Pages at that point;



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     PASSWD(4)                                               PASSWD(4)



          +@name means to insert the entries for all members of the
          network group name at that point.  If a + entry has a non-
          null password, directory, gecos, or shell field, they will
          overide what is contained in the Yellow Pages.  The
          numerical user ID and group ID fields cannot be overridden.

     EXAMPLE
          Here is a sample /etc/passwd file:


               root:q.mJzTnu8icF.:0:10:superuser:/:/bin/csh
               tut:6k/7KCFRPNVXg:508:10:Bill Tuthill:/usr2/tut:/bin/csh
               +john:
               +@documentation:no-login:
               +:::Guest

          In this example, there are specific entries for users root
          tut, in case the Yellow Pages are out of order.  The user
          will have his password entry in the Yellow Pages
          incorporated without change; anyone in the netgroup
          documentation will have their password field disabled, and
          anyone else will be able to log in with their usual
          password, shell, and home directory, but with a gecos field
          of Guest.

          The password file resides in the /etc directory.  Because of
          the encrypted passwords, it has general read permission and
          can be used, for example, to map numerical user ID's to
          names.

          Appropriate precautions must be taken to lock the
          /etc/passwd file against simultaneous changes if it is to be
          edited with a text editor.

     FILES
          /etc/passwd

     SEE ALSO
          getpwent(3), login(1), crypt(3), passwd(1), group(4)

     ORIGIN
          Sun Microsystems, with changes for Silicon Graphics, Inc.













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