TTYS(5)                       File Formats Manual                      TTYS(5)

NAME
     ttys – terminal initialization information

DESCRIPTION
     The file ttys contains information that is used by various routines to
     initialize and control the use of terminal special files.  This
     information is read with the getttyent(3) library routines.  There is one
     line in the ttys file per special device file.  Fields are separated by
     tabs and/or spaces.  Fields comprised of more than one word should be
     enclosed in double quotes (``"'').  Blank lines and comments may appear
     anywhere in the file; comments are delimited by hash marks (``#'') and
     new lines.  Any unspecified fields will default to null.

     The first field is normally the name of the terminal special file as it
     is found in /dev.  However, it can be any arbitrary string when the
     associated command is not related to a tty.

     The second field of the file is the command to execute for the line,
     usually getty(8), which initializes and opens the line, setting the
     speed, waiting for a user name and executing the login(1) program.  It
     can be, however, any desired command, for example the start up for a
     window system terminal emulator or some other daemon process, and can
     contain multiple words if quoted.

     The third field is the type of terminal usually connected to that tty
     line, normally the one found in the termcap(5) data base file.  The
     environment variable TERM is initialized with the value by either
     getty(8) or login(1).

     The remaining fields set flags in the ty_status entry (see getttyent(3)),
     specify a window system process that launchd(8) will maintain for the
     terminal line, optionally determine the type of tty (whether dialin,
     network or otherwise), or specify a tty group name that allows the login
     class database (see login.conf(5)) to refer to many ttys as a group, to
     selectively allow or deny access or enable or disable accounting
     facilities for ttys as a group.

     As flag values, the strings ``on'' and ``off'' specify that launchd(8)
     should (should not) execute the command given in the second field.
     ``onifconsole'' will cause this line to be enabled if and only if it is
     an active kernel console device (it is equivalent to ``on'' in this
     case).  The flag ``onifexists'' will cause this line to be enabled if and
     only if the name exists.  If the name starts with a ``/'', it will be
     considered an absolute path.  Otherwise, it is considered a path relative
     to /dev.  The flag ``secure'' (if the console is enabled) allows users
     with a uid of 0 to login on this line.  The flag ``dialup'' indicates
     that a tty entry describes a dialin line, and ``network'' is obsolete and
     does nothing.  Either of these strings may also be specified in the
     terminal type field.  The string ``window='' may be followed by a quoted
     command string which launchd(8) will execute before starting the command
     specified by the second field.

     The string ``group='' may be followed by a group name comprised of
     alphanumeric characters that can be used by login.conf(5) to refer to
     many tty lines as a group to enable or disable access and accounting
     facilities.  If no group is specified, then the tty becomes a member of
     the group "none".  For backwards compatibility, the ``group='' should
     appear last on the line, immediately before the optional comment.

     Both the second field and any command specified with ``window='' will be
     split into words and executed using execve(2).  Words are separated by
     any combinations of tabs and spaces.  Arguments containing whitespace
     should be enclosed in single quotes (').  Note that no shell-style
     globbing or other variable substitution occurs.

FILES
     /etc/ttys

NUMERIC SEQUENCES
     Numeric sequences of terminals can be represented in a more compact
     format.  A matching pair of square bracket may enclose two numbers (the
     start and stop values), separated by a hyphen.  The numbers are assumed
     to be decimal, unless prefixed with ``0x'', in which case they are
     interpreted as hexadecimal.  The number of characters (not including any
     ``0x'') in the starting value gives the minimum width; sequence values
     are zero padded up to this width.  Thus ``tty[00-07]'' represents the
     eight terminals ``tty00'' through ``tty07''.

EXAMPLES
     # root login on console at 1200 baud
     console "/usr/libexec/getty std.1200"   vt100   on secure
     # the sequence of eight terminals tty00 through tty07
     tty[00-07]     "/usr/libexec/getty std.9600"  vt100      on
     # Network pseudo ttys -- don't enable getty
     ttyp0   none    network
     ttyp1   none    network off
     # All sixteen of a pseudo tty sequence
     ttyq[0x0-0xf]  none                           network

SEE ALSO
     login(1), getttyent(3), ttyslot(3), gettytab(5), termcap(5), getty(8),
     launchd(8)

HISTORY
     A ttys file appeared in Version 6 AT&T UNIX.

macOS 15.2                       June 1, 2021                       macOS 15.2