getty -- System Administration

Terminal initialization
/etc/getty type

The initialization process init  invokes getty for each device indicated in
the file /etc/ttys. getty tries to read a user name from the terminal which
is the standard input,  adapting its mode settings accordingly.  Then getty
invokes login with the name read.   This process may set delays, mapping of
upper to lower case, speed, and whether the terminal normally uses carriage
return or linefeed to terminate input.

If the terminal baud rate is wrong, the login message printed by getty will
appear  garbled.   If  the specified  type  indicates  variable speeds,  as
described below, hitting BREAK will try the next speed.

init passes the third character in a line of the file /etc/ttys as the type
argument to  getty. type conveys  information about the  terminal port.  An
upper-case letter in the range A  to S specifies a hard-wired baud rate, as
indicated in  the header file  <sgtty.h>. Other characters  specify a
range of speeds suitable  to a dial-in modem.  The following variable-speed
settings are recognized:

0  Cycles through speeds 300, 1200, 150, and 110 baud, in that order.  This
   is a good default setting for dial-in ports.

-  Teletype model 33, fixed at 110 baud.

1  Teletype model 37, fixed at 150 baud.

2  9600 baud with delays (e.g., Tektronix 4104).

3  Cycles between  2400, 1200,  and 300 baud.   This is used  with 2400-bps
   modems.

4  DECwriter (LA36) with delays.

5  Like 3, but starts at 300 baud.

getty  recognizes  the   following  fixed-speed  settings,  for  hard-wired
terminals:

    A   50 baud
    B   75 baud
    C   110 baud
    D   134 baud
    E   150 baud
    F   200 baud
    G   300 baud
    H   600 baud
    I   1200 baud
    J   1800 baud
    K   2000 baud
    L   2400 baud
    M   3600 baud
    N   4800 baud
    O   7200 baud
    P   9600 baud
    Q   19200 baud
    R   EXT
    S   EXT

Files

/etc/tty
<sgtty.h>

See Also

Administering COHERENT,
init,
ioctl(),
login,
sgtty.h,
stty,
ttys

© 2012 by Stephen A. Ness