Provided by: util-linux_2.14-1ubuntu2_i386 bug

NAME

       agetty - alternative Linux getty

SYNOPSIS

       agetty  [-8ihLmnUw]  [-f  issue_file]  [-l login_program] [-I init] [-t
       timeout] [-H login_host] port baud_rate,...  [term]
       agetty [-8ihLmnw] [-f issue_file]  [-l  login_program]  [-I  init]  [-t
       timeout] [-H login_host] baud_rate,...  port [term]

DESCRIPTION

       agetty  opens  a  tty  port,  prompts  for a login name and invokes the
       /bin/login command. It is normally invoked by init(8).

       agetty has several non-standard features that are useful for hard-wired
       and for dial-in lines:

       o      Adapts  the tty settings to parity bits and to erase, kill, end-
              of-line and uppercase characters when it  reads  a  login  name.
              The  program can handle 7-bit characters with even, odd, none or
              space parity, and 8-bit characters with no parity. The following
              special  characters  are  recognized: @ and Control-U (kill); #,
              DEL and back space (erase); carriage return and line  feed  (end
              of line).

       o      Optionally  deduces  the  baud  rate  from  the CONNECT messages
              produced by Hayes(tm)-compatible modems.

       o      Optionally does not hang up when it is given an  already  opened
              line (useful for call-back applications).

       o      Optionally does not display the contents of the /etc/issue file.

       o      Optionally  displays  an  alternative  issue  file  instead   of
              /etc/issue.

       o      Optionally does not ask for a login name.

       o      Optionally  invokes  a  non-standard  login  program  instead of
              /bin/login.

       o      Optionally turns on hard-ware flow control

       o      Optionally forces the line to be local with no need for  carrier
              detect.

       This   program   does   not   use  the  /etc/gettydefs  (System  V)  or
       /etc/gettytab (SunOS 4) files.

ARGUMENTS

       port   A path name  relative  to  the  /dev  directory.  If  a  "-"  is
              specified,  agetty  assumes  that  its standard input is already
              connected to a tty port and that a connection to a  remote  user
              has already been established.

              Under  System  V,  a  "-"  port argument should be preceded by a
              "--".

       baud_rate,...
              A comma-separated list of one or  more  baud  rates.  Each  time
              agetty  receives a BREAK character it advances through the list,
              which is treated as if it were circular.

              Baud rates should be specified in descending order, so that  the
              null   character  (Ctrl-@)  can  also  be  used  for  baud  rate
              switching.

       term   The value to be used for the  TERM  environment  variable.  This
              overrides  whatever  init(8)  may  have set, and is inherited by
              login and the shell.

OPTIONS

       -8     Assume that  the  tty  is  8-bit  clean,  hence  disable  parity
              detection.

       -h     Enable  hardware  (RTS/CTS)  flow  control. It is left up to the
              application to disable software (XON/XOFF) flow  protocol  where
              appropriate.

       -i     Do  not  display  the  contents  of /etc/issue (or other) before
              writing the login prompt. Terminals or  communications  hardware
              may  become  confused  when  receiving lots of text at the wrong
              baud rate; dial-up scripts may  fail  if  the  login  prompt  is
              preceded by too much text.

       -f issue_file
              Display  the contents of issue_file instead of /etc/issue.  This
              allows custom messages to be displayed on  different  terminals.
              The -i option will override this option.

       -I initstring
              Set  an  initial  string  to  be sent to the tty or modem before
              sending anything else. This may be used to initialize  a  modem.
              Non printable characters may be sent by writing their octal code
              preceded by a backslash (\). For  example  to  send  a  linefeed
              character (ASCII 10, octal 012) write \012.

       -l login_program
              Invoke  the specified login_program instead of /bin/login.  This
              allows the use of a non-standard login program (for example, one
              that  asks  for  a  dial-up  password  or  that uses a different
              password file).

       -H login_host
              Write the specified login_host into the utmp file. (Normally, no
              login  host  is  given, since agetty is used for local hardwired
              connections and consoles. However, this option can be useful for
              identifying terminal concentrators and the like.

       -m     Try to extract the baud rate the CONNECT status message produced
              by Hayes(tm)-compatible modems. These status messages are of the
              form:  "<junk><speed><junk>".   agetty  assumes  that  the modem
              emits its status message at the same  speed  as  specified  with
              (the first) baud_rate value on the command line.

              Since  the  -m  feature  may fail on heavily-loaded systems, you
              still should enable BREAK processing by enumerating all expected
              baud rates on the command line.

       -n     Do  not  prompt  the  user for a login name. This can be used in
              connection with -l option to invoke a non-standard login process
              such  as a BBS system. Note that with the -n option, agetty gets
              no input from user who logs in and therefore won’t  be  able  to
              figure out parity, character size, and newline processing of the
              connection. It defaults to space parity, 7 bit  characters,  and
              ASCII  CR  (13)  end-of-line character.  Beware that the program
              that agetty starts (usually /bin/login) is run as root.

       -t timeout
              Terminate if no user name could be read within timeout  seconds.
              This option should probably not be used with hard-wired lines.

       -L     Force  the  line  to  be  a  local line with no need for carrier
              detect. This can be useful when  you  have  a  locally  attached
              terminal  where  the serial line does not set the carrier detect
              signal.

       -U     Turn on support for detecting an uppercase only terminal.   This
              setting  will  detect  a  login name containing only capitals as
              indicating an uppercase only terminal and turn on some upper  to
              lower  case  conversions.  Note that this has no support for any
              unicode characters.

       -w     Wait for the user or the modem to send a  carriage-return  or  a
              linefeed character before sending the /etc/issue (or other) file
              and the login prompt. Very useful  in  connection  with  the  -I
              option.

EXAMPLES

       This  section  shows  examples for the process field of an entry in the
       /etc/inittab file.  You’ll have to prepend appropriate values  for  the
       other fields.  See inittab(5) for more details.

       For a hard-wired line or a console tty:
            /sbin/agetty 9600 ttyS1

       For  a  directly  connected  terminal  without  proper  carriage detect
       wiring: (try this if your terminal just sleeps instead of giving you  a
       password: prompt.)
            /sbin/agetty -L 9600 ttyS1 vt100

       For a old style dial-in line with a 9600/2400/1200 baud modem:
            /sbin/agetty -mt60 ttyS1 9600,2400,1200

       For  a  Hayes  modem  with a fixed 115200 bps interface to the machine:
       (the example init string turns off modem echo and result  codes,  makes
       modem/computer DCD track modem/modem DCD, makes a DTR drop cause a dis-
       connection and turn on auto-answer after 1 ring.)
            /sbin/agetty -w -I ’ATE0Q1&D2&C1S0=1\015’ 115200 ttyS1

ISSUE ESCAPES

       The issue-file (/etc/issue or the file set  with  the  -f  option)  may
       contain  certain escape codes to display the system name, date and time
       etc. All escape codes consist of a backslash (\)  immediately  followed
       by one of the letters explained below.

       b      Insert the baudrate of the current line.

       d      Insert the current date.

       s      Insert the system name, the name of the operating system.

       l      Insert the name of the current tty line.

       m      Insert the architecture identifier of the machine, eg. i486

       n      Insert  the nodename of the machine, also known as the hostname.

       o      Insert the NIS domainname of the machine.

       O      Insert the DNS domainname of the machine.

       r      Insert the release number of the OS, eg. 1.1.9.

       t      Insert the current time.

       u      Insert the number of current users logged in.

       U      Insert the string "1 user" or  "<n>  users"  where  <n>  is  the
              number of current users logged in.

       v      Insert the version of the OS, eg. the build-date etc.

       Example: On my system, the following /etc/issue file:

              This is \n.\o (\s \m \r) \t

       displays as

              This is thingol.orcan.dk (Linux i386 1.1.9) 18:29:30

FILES

       /var/run/utmp, the system status file.
       /etc/issue, printed before the login prompt.
       /dev/console, problem reports (if syslog(3) is not used).
       /etc/inittab, init(8) configuration file.

BUGS

       The baud-rate detection feature (the -m option) requires that agetty be
       scheduled soon enough after completion of a dial-in call (within 30  ms
       with  modems that talk at 2400 baud). For robustness, always use the -m
       option in combination with a multiple baud rate command-line  argument,
       so that BREAK processing is enabled.

       The  text  in  the  /etc/issue file (or other) and the login prompt are
       always output with 7-bit characters and space parity.

       The baud-rate detection feature (the -m option) requires that the modem
       emits its status message after raising the DCD line.

DIAGNOSTICS

       Depending  on  how  the  program  was  configured,  all diagnostics are
       written to the console device or reported via the  syslog(3)  facility.
       Error  messages  are  produced  if the port argument does not specify a
       terminal device; if there is no utmp  entry  for  the  current  process
       (System V only); and so on.

AUTHOR(S)

       W.Z. Venema <wietse@wzv.win.tue.nl>
       Eindhoven University of Technology
       Department of Mathematics and Computer Science
       Den Dolech 2, P.O. Box 513, 5600 MB Eindhoven, The Netherlands

       Peter Orbaek <poe@daimi.aau.dk>
       Linux port and more options. Still maintains the code.

       Eric Rasmussen <ear@usfirst.org>
       Added -f option to display custom login messages on different terminals.

AVAILABILITY

       The agetty command is part of the util-linux-ng package and is
       available from ftp://ftp.kernel.org/pub/linux/utils/util-linux-ng/.

                                                                     AGETTY(8)