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       mgetty - smart modem getty


       mgetty [options] ttydevice [gettydefs]


       Mgetty is a ‘‘smart’’ getty replacement, designed to be used with hayes
       compatible  data  and  data/fax  modems.   Mgetty  knows  about   modem
       initialization, manual modem answering (so your modem doesn’t answer if
       the machine isn’t ready), UUCP locking (so you can use the same  device
       for  dial-in  and  dial-out).   Mgetty  provides very extensive logging

       This manpage doesn’t try to detail mgetty  setup  in  detail,  it  just
       lists  the  most  important options. For detailed instructions, see the
       info file (mgetty.texi).


       -k <space>
              Tells mgetty to leave <space> kbytes free on disk when receiving
              a fax.

       -x <debug level>
              Use  the  given  level  of  verbosity  for  logging - 0 means no
              logging,  9  is  really  noisy.  The   log   file   is   usually

       -s <speed>
              Set the port speed to use, e.g. "-s 19200".

       -r     Tells  mgetty  that it is running on a direct line. UUCP locking
              is done, but no modem initialization whatsoever.

       -p <login prompt>
              Use the given string to prompt  users  for  their  login  names.
              Various  tokens  are allowed in this string. These tokens are: @
              for the system name, \n, \r, \g, \b, \v,  \f,  \t  for  newline,
              carriage  return,  bell, backspace, vertical tab, form feed, and
              tab, respectively.  \P and  \L  will  expand  to  the  tty  name
              ("ttyS0").  \Y  will give the Caller ID, \I the "CONNECT foobar"
              string returned by the modem, and \S will output the port speed.
              \s,  \m,  \V,  \R  represent  the operating system, the hardware
              name, the OS version, the OS release.  \N and \U give the number
              of  users  currently  logged  in.   \C  will be changed into the
              result of ctime(), and \D and \T will output the date and  time,
              respectively.    Finally,    \<digit>    will   use   digit   as
              octal/decimal/hexadecimal representation  of  the  character  to

              The default prompt is specified at compile time.

       -n #   Tells mgetty to pick up the phone after the #th RING. Default is

       -R <t> Tells mgetty to go into "ringback" (aka "ring-twice") mode. That
              means:  the first call is never answered, instead the caller has
              to hang up after the phone RINGs, wait 30 seconds, and then call
              again  in the next <t> seconds for mgetty to pick up. If no call
              comes, mgetty will exit.

              I do not really recommend using this, better get a second  phone
              line for the modem.

       -i <issue file>
              Output  <issue  file> instead of /etc/issue before prompting for
              the user name. The same token substitutions as for the the login
              prompt are done in this file.

       -D     Tells mgetty that the modem is to be treated as a DATA modem, no
              fax initalization is attempted.

       -F     Tells mgetty that DATA calls  are  not  allowed  and  the  modem
              should be set to Fax-Only.

       -C <class>
              Tells mgetty how to treat the modem. Possible values for <class>
              are "auto" (default, try to find out whether the modem  supports
              fax), "cls2" (use the class 2 fax command set, even if the modem
              supports class 2.0), "c2.0" (use the class 2.0 fax command set),
              "data" (data only, exactly as the -D switch).

       -S <g3 file>
              If  a  call  comes in and requests fax polling, mgetty will send
              the named file. Note: not all fax modems support poll sending.

       -I <fax id>
              Use the given fax station ID for fax  identification.  Not  used
              for data modems.

       -b     Open  the  port  in blocking mode. Best used in combination with
              "-r". This is the default if mgetty is called as getty.  You may
              want  to  use  this  if you want to make use of the two-device /
              kernel-locking scheme of the Linux and SunOS  operating  systems
              (/dev/ttyS..  and  /dev/cua..). I do not recommend it, it’s just
              include for completeness, and to be able  to  use  mgetty  as  a
              full-featured getty replacement.

       -a     Use  autobauding.  That  is,  after a connection is made, mgetty
              parses the "CONNECT foo" response code of the modem and sets the
              port  speed  to  the  first  integer  found  after the "CONNECT"
              string, "foo" in this example.  You  need  this  if  your  modem
              insist  on  changing  its  DTE  speed to match the line speed. I
              recommend against using it, better leave the port  speed  locked
              at  a  fixed  value. The feature is included because there exist
              old modems that cannot use a fixed (locked) port speed.

       -mexpect send ...’
              Set the "chat sequence" that is used to  initialize  the  modem.
              For  an  empty  expect part, use empty double quotes (""). Since
              the sequence contains spaces, you have to enclose all of  it  in
              single quotes(’’). Example:

              mgetty -m ’"" ATH0 OK’


              Main configuration file.

              controls  whether  (and  when)  mgetty  should  call  some other
              program for user login instead of /bin/login. How this  is  done
              is explained in this file.

              controls  acceptance/denial  of  incoming  calls  based  on  the
              caller’s number.  Available only if you  have  "caller  ID"  and
              your modem supports it.

              controls  whether  mgetty should pick up the phone upon incoming
              calls. If the file exists, calls are completely ignored. You can
              use  this,  for example, to stop mgetty during day time, and let
              it  pick  up  at  night   only,   by   creating   and   removing
              /etc/nologin.ttyxx via the cron program at the appropriate time.

              will be printed after a connection is  established,  and  before
              the with the ’-i’ option.

              Debug log file, see below.


       If mgetty doesn’t work the way it should, the main source of diagnostic
       data    is    the    log    file.     It    can     be     found     in
       "/var/log/mgetty/mg_ttyxx.log"   (for   the   mgetty  process  handling
       "ttyxx").  If it doesn’t contain enough details, enhance the log  level
       with the ’-x’ option to mgetty, e.g. "-x 5".

       Many  of  the common problems and solutions are discussed in the mgetty
       manual   and   the   FAQ.     Please    see    the    WWW    page    at for both.


       Not  all  of  mgetty  configuration can be done at run-time yet. Things
       like flow control and file paths (log file /  lock  file)  have  to  be
       configured by changing the source and recompiling.

       Users never read manuals...


       g32pbm(1), sendfax(8), getty(8), mgettydefs(4),


       mgetty is Copyright (C) 1993 by Gert Doering, <>.