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adduser - command for adding new users



      adduser - command for adding new users


      adduser [-CDENShq] [-G groups] [-L login_class] [-d partition] [-f file]
              [-g login_group] [-k dotdir] [-m message_file] [-s shell]
              [-u uid_start] [-w type]


      The adduser utility is a shell script, implemented around the pw(8) com‐
      mand, for adding new users.  It creates passwd/group entries, a home
      directory, copies dotfiles and sends the new user a welcome message.  It
      supports two modes of operation.  It may be used interactively at the
      command line to add one user at a time, or it may be directed to get the
      list of new users from a file and operate in batch mode without requiring
      any user interaction.


              Login name.  The user name is restricted to whatever pw(8) will
              accept.  Generally this means it may contain only lowercase char‐
              acters or digits but cannot begin with the ‘-’ character.  Maxi‐
              mum length is 16 characters.  The reasons for this limit are his‐
              torical.  Given that people have traditionally wanted to break
              this limit for aesthetic reasons, it has never been of great
              importance to break such a basic fundamental parameter in UNIX.
              You can change UT_NAMESIZE in #include <utmp.h>
              and recompile the world; people have done this and it works, but
              you will have problems with any precompiled programs, or source
              that assumes the 8-character name limit, such as NIS.  The NIS
              protocol mandates an 8-character username.  If you need a longer
              login name for e-mail addresses, you can define an alias in
      full name
              This is typically known as the gecos field and usually contains
              the user’s full name.  Additionally, it may contain a comma sepa‐
              rated list of values such as office number and work and home
              phones.  If the name contains an ampersand it will be replaced by
              the capitalized login name when displayed by other programs.  The
              ‘:’ character is not allowed.
      shell   Unless the -S argument is supplied only valid shells from the
              shell database (/etc/shells) are allowed.  In addition, either
              the base name or the full path of the shell may be supplied.
      UID     Automatically generated or your choice.  It must be less than
      GID/login group
              Automatically generated or your choice.  It must be less than
              You may choose an empty password, disable the password, use a
              randomly generated password or specify your own plaintext pass‐
              word, which will be encrypted before being stored in the user
      Perhaps you are missing what can be done with this scheme that falls
      apart with most other schemes.  With each user in their own group, they
      can safely run with a umask of 002 instead of the usual 022 and create
      files in their home directory without worrying about others being able to
      change them.
      For a shared area you create a separate UID/GID (like cvs or ncvs on
      freefall), you place each person that should be able to access this area
      into that new group.
      This model of UID/GID administration allows far greater flexibility than
      lumping users into groups and having to muck with the umask when working
      in a shared area.
      I have been using this model for almost 10 years and found that it works
      for most situations, and has never gotten in the way.  (Rod Grimes)


      The adduser utility reads its configuration information from
      /etc/adduser.conf.  If this file does not exist, it will use predefined
      defaults.  While this file may be edited by hand, the safer option is to
      use the -C command line argument.  With this argument, adduser will start
      interactive input, save the answers to its prompts in /etc/adduser.conf,
      and promptly exit without modifying the user database.  Options specified
      on the command line will take precedence over any values saved in this


      -C      Create new configuration file and exit.  This option is mutually
              exclusive with the -f option.
      -d partition
              Home partition.  Default partition, under which all user directo‐
              ries will be located.  The /nonexistent partition is considered
              special.  The adduser script will not create and populate a home
              directory by that name.  Otherwise, by default it attempts to
              create a home directory.
      -D      Do not attempt to create the home directory.
      -E      Disable the account.  This option will lock the account by
              prepending the string “*LOCKED*” to the password field.  The
              account may be unlocked by the super-user with the pw(8) command:
                    pw unlock [name | uid]
      -f file
              Get the list of accounts to create from file.  If file is “-”,
              then get the list from standard input.  If this option is speci‐
              fied, adduser will operate in batch mode and will not seek any
              user input.  If an error is encountered while processing an
              account, it will write a message to standard error and move to
              the next account.  The format of the input file is described
      -g login_group
              Normally, if no login group is specified, it is assumed to be the
              same as the username.  This option makes login_group the default.
      -G groups
              Space-separated list of additional groups.  This option allows
              the user to specify additional groups to add users to.  The user
              is a member of these groups in addition to their login group.
      -h      Print a summary of options and exit.
      -k directory
              Copy files from directory into the home directory of new users;
     will be renamed to .foo.
      -L login_class
              Set default login class.
      -m file
              Send new users a welcome message from file.  Specifying a value
              of no for file causes no message to be sent to new users.  Please
              note that the message file can reference the internal variables
              of the adduser script.
      -N      Do not read the default configuration file.
      -q      Minimal user feedback.  In particular, the random password will
              not be echoed to standard output.
      -s shell
              Default shell for new users.  The shell argument may be the base
              name of the shell or the full path.  Unless the -S argument is
              supplied the shell must exist in /etc/shells or be the special
              shell nologin to be considered a valid shell.
      -S      The existence or validity of the specified shell will not be
      -u uid  Use UIDs from uid on up.
      -w type
              Password type.  The adduser utility allows the user to specify
              what type of password to create.  The type argument may have one
              of the following values:
              no      Disable the password.  Instead of an encrypted string,
                      the password field will contain a single ‘*’ character.
                      The user may not log in until the super-user manually
                      enables the password.
              none    Use an empty string as the password.
              yes     Use a user-supplied string as the password.  In interac‐
                      tive mode, the user will be prompted for the password.
                      In batch mode, the last (10th) field in the line is
                      assumed to be the password.
              random  Generate a random string and use it as a password.  The
                      password will be echoed to standard output.  In addition,
                      it will be available for inclusion in the message file in
                      the randompass variable.


      When the -f option is used, the account information must be stored in a
      specific format.  All empty lines or lines beginning with a ‘#’ will be
      ignored.  All other lines must contain ten colon (‘:’) separated fields
      as described below.  Command line options do not take precedence over
      values in the fields.  Only the password field may contain a ‘:’ charac‐
      ter as part of the string.
      name      Login name.  This field may not be empty.
      uid       Numeric login user ID.  If this field is left empty, it will be
                automatically generated.
      gid       Numeric primary group ID.  If this field is left empty, a group
                with the same name as the user name will be created and its GID
                will be used instead.
      class     Login class.  This field may be left empty.
      change    Password ageing.  This field denotes the password change date
                for the account.  The format of this field is the same as the
                format of the -p argument to pw(8).  It may be dd-mmm-yy[yy],
                where dd is for the day, mmm is for the month in numeric or
                alphabetical format: “10” or “Oct”, and yy[yy] is the four or
                two digit year.  To denote a time relative to the current date
                the format is: +n[mhdwoy], where n denotes a number, followed
                by the minutes, hours, days, weeks, months or years after which
                the password must be changed.  This field may be left empty to
                turn it off.
      expire    Account expiration.  This field denotes the expiry date of the
                account.  The account may not be used after the specified date.
                The format of this field is the same as that for password age‐
                ing.  This field may be left empty to turn it off.
      gecos     Full name and other extra information about the user.
      home_dir  Home directory.  If this field is left empty, it will be auto‐
                matically created by appending the username to the home parti‐
                tion.  The /nonexistent home directory is considered special
                and is understood to mean that no home directory is to be cre‐
                ated for the user.
      shell     Login shell.  This field should contain either the base name or
                the full path to a valid login shell.
      password  User password.  This field should contain a plaintext string,
                which will be encrypted before being placed in the user
                database.  If the password type is yes and this field is empty,
                it is assumed the account will have an empty password.  If the
                password type is random and this field is not empty, its con‐
                tents will be used as a password.  This field will be ignored
                if the -p option is used with a no or none argument.  Be care‐
                ful not to terminate this field with a closing ‘:’ because it
                will be treated as part of the password.


      /etc/master.passwd    user database
      /etc/group            group database
      /etc/shells           shell database
      /etc/login.conf       login classes database
      /etc/adduser.conf     configuration file for adduser
      /etc/adduser.message  message file for adduser
      /usr/share/skel       skeletal login directory
      /var/log/adduser      logfile for adduser
      chpass(1), passwd(1), adduser.conf(5), aliases(5), group(5),
      login.conf(5), passwd(5), shells(5), adding_user(8), pw(8), pwd_mkdb(8),
      rmuser(8), vipw(8), yp(8)


      The adduser command appeared in FreeBSD 2.1.


      This manual page and the original script, in Perl, was written by Wolfram
      Schneider 〈〉.  The replacement script, written as a
      Bourne shell script with some enhancements, and the man page modification
      that came with it were done by Mike Makonnen 〈〉.


      In order for adduser to correctly expand variables such as $username and
      $randompass in the message sent to new users, it must let the shell eval‐
      uate each line of the message file.  This means that shell commands can
      also be embedded in the message file.  The adduser utility attempts to
      mitigate the possibility of an attacker using this feature by refusing to
      evaluate the file if it is not owned and writable only by the root user.
      In addition, shell special characters and operators will have to be
      escaped when used in the message file.
      Also, password ageing and account expiry times are currently settable
      only in batch mode or when specified in /etc/adduser.conf.  The user
      should be able to set them in interactive mode as well.


Based on BSD UNIX
FreeBSD is an advanced operating system for x86 compatible (including Pentium and Athlon), amd64 compatible (including Opteron, Athlon64, and EM64T), UltraSPARC, IA-64, PC-98 and ARM architectures. It is derived from BSD, the version of UNIX developed at the University of California, Berkeley. It is developed and maintained by a large team of individuals. Additional platforms are in various stages of development.