Provided by: util-linux_2.19.1-2ubuntu3_i386 bug


       agetty - alternative Linux getty


       agetty  [-c8ihLmnsUw]  [-f issue_file] [-l login_program] [-I init] [-t
       timeout] [-H login_host] port baud_rate,...  [term]


       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

       o      Optionally does not ask for a login name.

       o      Optionally  invokes  a  non-standard  login  program  instead of

       o      Optionally turns on hard-ware flow control

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

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


       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

              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

       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.


       -c     Don't reset terminal cflags (control modes). See termios(3)  for
              more details.

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

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

       -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

       -s     Try  to  keep  the  existing  baud rate. The baud rates from the
              command line are used when agetty receives a BREAK character.

       -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


       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


       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 (Linux i386 1.1.9) 18:29:30


       /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.


       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.


       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.


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

       Peter Orbaek <>
       Linux port and more options. Still maintains the code.

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


       The agetty command is part of the util-linux package and is available