GETTYTAB(5) File Formats Manual GETTYTAB(5)
NAME
gettytabterminal configuration data base
SYNOPSIS
gettytab
DESCRIPTION
The gettytab file is a simplified version of the termcap(5) data base used to describe terminal lines. The initial terminal login process getty(8) accesses the gettytab file each time it starts, allowing simpler reconfiguration of terminal characteristics. Each entry in the data base is used to describe one class of terminals.
 
Where to run getty(8) processes is normally defined by ttys(5).
 
There is a default terminal class, default, that is used to set global defaults for all other classes. (That is, the default entry is read, then the entry for the class required is used to override particular settings.) The default entry is also normally read by other programs that present login prompts to the user, such as telnetd(8), in order to retrieve the values of the he, hn, im, and if capabilities.
CAPABILITIES
Refer to termcap(5) for a description of the file layout. The default column below lists defaults obtained if there is no entry in the table obtained, nor one in the special default table.
Name
Type
Default
Description
ab
bool
false
Auto-baud speed select mechanism for the Micom 600 portselector. Selection is done by looking at how the character `\r' is garbled at 300, 1200, 4800, and 9600 baud.
al
str
NULL
user to auto-login instead of prompting
ap
bool
false
terminal uses any parity
bk
str
0377
alternative end of line character (input break)
b2
str
0377
alternative end of line character (input break)
c0
num
unused
tty control flags to write messages
c1
num
unused
tty control flags to read login name
c2
num
unused
tty control flags to leave terminal as
ce
bool
false
use crt erase algorithm
ck
bool
false
use crt kill algorithm
cl
str
NULL
screen clear sequence
co
bool
false
console - add ‘\r\n' after login prompt
cs
bool
false
clear screen based on terminal type in /etc/ttys
ds
str
^Y'
delayed suspend character
dx
bool
false
set DECCTLQ
ec
bool
false
leave echo OFF
ep
bool
false
terminal uses even parity
er
str
^?'
erase character
et
str
^D'
end of text (EOF) character
ev
str
NULL
initial environment
f0
num
unused
tty mode flags to write messages
f1
num
unused
tty mode flags to read login name
f2
num
unused
tty mode flags to leave terminal as
fl
str
^O'
output flush character
hc
bool
false
do NOT hangup line on last close
he
str
NULL
hostname editing string
hn
str
hostname
hostname
ht
bool
false
terminal has real tabs
i0
num
unused
tty input flags to write messages
i1
num
unused
tty input flags to read login name
i2
num
unused
tty input flags to leave terminal as
if
str
NULL
display named file before prompt, like /etc/issue
ig
bool
false
ignore garbage characters in login name
im
str
NULL
initial (banner) message
in
str
^C'
interrupt character
is
num
unused
input speed
kl
str
^U'
kill character
l0
num
unused
tty local flags to write messages
l1
num
unused
tty local flags to read login name
l2
num
unused
tty local flags to leave terminal as
lc
bool
false
terminal has lower case
lm
str
login:
login prompt
ln
str
^V'
``literal next'' character
lo
str
/usr/bin/login
program to exec when name obtained
mb
bool
false
do flow control based on carrier
nl
bool
false
terminal has (or might have) a newline character
nn
bool
false
do not prompt for a login name
np
bool
false
terminal uses no parity (i.e. 8-bit characters)
nx
str
default
next table (for auto speed selection)
o0
num
unused
tty output flags to write messages
o1
num
unused
tty output flags to read login name
o2
num
unused
tty output flags to leave terminal as
op
bool
false
terminal uses odd parity
os
num
unused
output speed
pc
str
\0'
pad character
pe
bool
false
use printer (hard copy) erase algorithm
pf
num
0
delay between first prompt and following flush (seconds)
pp
str
unused
PPP authentication program
ps
bool
false
line connected to a MICOM port selector
qu
str
^\'
quit character
rp
str
^R'
line retype character
rw
bool
false
do NOT use raw for input, use cbreak
sp
num
unused
line speed (input and output)
st
str
^T'
status character
su
str
^Z'
suspend character
tc
str
none
table continuation
to
num
0
timeout (seconds)
tt
str
NULL
terminal type (for environment)
ub
bool
false
do unbuffered output (of prompts etc)
we
str
^W'
word erase character
xc
bool
false
do NOT echo control chars as ‘^X'
xf
str
^S'
XOFF (stop output) character
xn
str
^Q'
XON (start output) character
 
The following capabilities are no longer supported by getty(8):
bd
num
0
backspace delay
cb
bool
false
use crt backspace mode
cd
num
0
carriage-return delay
fd
num
0
form-feed (vertical motion) delay
nd
num
0
newline (line-feed) delay
uc
bool
false
terminal is known upper case only
 
If no line speed is specified, speed will not be altered from that which prevails when getty is entered. Specifying an input or output speed will override line speed for stated direction only.
 
Terminal modes to be used for the output of the message, for input of the login name, and to leave the terminal set as upon completion, are derived from the boolean flags specified. If the derivation should prove inadequate, any (or all) of these three may be overridden with one of the c0, c1, c2, i0, i1, i2, l0, l1, l2, o0, o1, or o2 numeric specifications, which can be used to specify (usually in octal, with a leading '0') the exact values of the flags. These flags correspond to the termios c_cflag, c_iflag, c_lflag, and c_oflag fields, respectively. Each these sets must be completely specified to be effective. The f0, f1, and f2 are excepted for backwards compatibility with a previous incarnation of the TTY sub-system. In these flags the bottom 16 bits of the (32 bits) value contain the sgttyb sg_flags field, while the top 16 bits represent the local mode word.
 
Should getty(8) receive a null character (presumed to indicate a line break) it will restart using the table indicated by the nx entry. If there is none, it will re-use its original table.
 
Delays are specified in milliseconds, the nearest possible delay available in the tty driver will be used. Should greater certainty be desired, delays with values 0, 1, 2, and 3 are interpreted as choosing that particular delay algorithm from the driver.
 
The cl screen clear string may be preceded by a (decimal) number of milliseconds of delay required (a la termcap). This delay is simulated by repeated use of the pad character pc.
 
The initial message, and login message, im and lm may include any of the following character sequences, which expand to information about the environment in which getty(8) is running.
 
%d
The current date.
%h
The hostname of the machine, which is normally obtained from the system using gethostname(3), but may also be overridden by the hn table entry. In either case it may be edited with the he string. A '@' in the he string causes one character from the real hostname to be copied to the final hostname. A '#' in the he string causes the next character of the real hostname to be skipped. Each character that is neither '@' nor '#' is copied into the final hostname. Surplus '@' and '#' characters are ignored.
%t
The tty name.
%m, %r, %s, %v
The type of machine, release of the operating system, name of the operating system, and version of the kernel, respectively, as returned by uname(3).
%%
A “%” character.
 
When getty execs the login process, given in the lo string (usually “/usr/bin/login”), it will have set the environment to include the terminal type, as indicated by the tt string (if it exists). The ev string, can be used to enter additional data into the environment. It is a list of comma separated strings, each of which will presumably be of the form name=value.
 
If a non-zero timeout is specified, with to, then getty will exit within the indicated number of seconds, either having received a login name and passed control to login(1), or having received an alarm signal, and exited. This may be useful to hangup dial in lines.
 
Output from getty(8) is even parity unless op or np is specified. The op string may be specified with ap to allow any parity on input, but generate odd parity output. Note: this only applies while getty is being run, terminal driver limitations prevent a more complete implementation. getty(8) does not check parity of input characters in RAW mode.
 
If pp string is specified and a Point to Point Protocol (PPP) link bringup sequence is recognized, getty(8) will invoke the program referenced by the pp string, e.g. pppd(8). This can be used to handle incoming PPP calls.
SEE ALSO
HISTORY
The gettytab file format appeared in 4.2BSD.
BUGS
The special characters (erase, kill, etc.) are reset to system defaults by login(1). In all cases, '#' or '^H' typed in a login name will be treated as an erase character, and '@' will be treated as a kill character.
 
The delay stuff is a real crock. Apart from its general lack of flexibility, some of the delay algorithms are not implemented. The terminal driver should support sane delay settings.
 
The he capability is stupid.
 
The termcap(5) format is horrid, something more rational should have been chosen.