dial -- System Administration

File that tells UUCP how to dial a system
/usr/lib/uucp/dial

The file /usr/lib/uucp/dial holds information about dialers.  A dialer is a
device,  usually a  modem,  through which  uucico or  cu ``dials''  another
computer system.  The daemon uucico  and the command cu use the information
in this file to talk to dialers.

dial  consists of  a series  of descriptions, each  of which  describes one
dialer.   A description  consists  of one  or more  commands; each  command
defines an  aspect of how  to manipulate the dialer.   Descriptions must be
separated by one blank line.

The following describes the commands you can use in a description:

dialer name
     Name the  dialer being described.  Each description  must begin with a
     dialer command.  For example, the command

         dialer trailblazer

     introduces the  description for the device  named trailblazer. (A name
     need not be technical: you can also use names like joe or junk_modem.)

chat from_modem to_modem ... from_modem
     This command gives the chat script with which uucico and cu initialize
     the dialer and have it dial a remote system.  chat can have any number
     of arguments:  the odd-numbered strings  are received from  the modem,
     and the even-numbered ones sent to it.  Strings are separated by space
     character; therefore, no string can contain a literal space character.
     To represent  a space character  in a string, use  the escape sequence
     \s.

     If, at a given point in the conversation, nothing is expected from the
     modem or  is to  be sent to  it, then use  an empty pair  of quotation
     marks as a placeholder.

     Please note  that unlike the  chat script used  in file sys,  the chat
     script in  dial contains  only the information  by which the  modem is
     accessed: it  does not contain  information about how to  log into the
     remote computer system.

     A chat script can contain the following escape sequences:

         \D  Telephone number of the remote system
         \T  Telephone number  plus dialcode translation
         \M  Do not require carrier
         \m  Require carrier, fail if not present
         \s  Represent a space character

     uucico  and cu  use  the command  phone in  file /usr/lib/uucp/sys  to
     expand the escape sequence \D.

     The following gives an example chat script:

         chat  "" ATQ0V1E1L2M1DT\D CONNECT\s2400

     The pair  of quotation  marks tells uucico  (or cu) to  expect nothing
     from  the modem,  and to  send  immediately the  string ATQ0V1E1L2M1DT
     followed  by the  telephone number  of the remote  system.  This  is a
     typical  send string  for  a Hayes-compatible,  2400-baud modem.   The
     string also  sets certain  registers within  the modem: Q0V1  turns on
     verbal result  codes, E1 turns on echoing, and  L2M1 sets the duration
     and volume of the modem's speaker.

     The last  string in the chat  script gives the expect  string. This is
     the string  that the modem  sends when it has  succeeded in connecting
     with the  remote computer system.  In this example,  if the modem does
     not send

         CONNECT 2400

     then the  attempt to call the remote system  has failed.  This example
     shows, as  noted above,  that no  string to the  command chat  (or any
     other  command  used  in dial)  can  contain  a  space character.   To
     represent a  space character within a string,  use the escape sequence
     \s.

chat-timeout seconds
     This command  gives the number  of seconds to await  the expect string
     from the modem.  For example, the command

         chat-timeout 10

     tells uucico to wait ten seconds for the expected string.

chat-fail failure_string
     This command  defines the string  that, when received  from the modem,
     indicates that  a connection attempt has failed.   uucico and cu abort
     when  they receive  failure_string.  A dialer's  description can  have
     multiple  chat-fail commands  (after  all, a  call can  fail for  many
     different reasons).  For example, the commands

         chat-fail   BUSY
         chat-fail   NO\sCARRIER

     tell uucico and cu to abort  when they receive either the strings BUSY
     or NO CARRIER.

chat-seven-bit true|false
     If true, strip  all bits to seven bits before  comparing them with the
     expect string within the chat script.

chat-program program [ arguments ]
     Run program before  executing the chat script.  The optional arguments
     are passed to program.  The following escape sequences can be embedded
     within arguments:

          \Y Name of the port device
          \S Speed of the port
          \\ A literal backspace character

     uucico expands  these escape sequences  before it passes  arguments to
     command.

dialtone stirng
     string is  the code sequence that  tells the modem to  wait for a dial
     tone (e.g.,  if you  must dial  `9' and then  pause briefly to  get an
     outside  line).  uucico  outputs string whenever  it encounters  a `='
     within a telephone number.  The default code is a comma.

pause string
     string is  the code  sequence that  tells the modem  to pause  for one
     second.  uucico  outputs string whenever it encounters  a `-' within a
     telephone number.  The default code is a comma.

carrier true|false
     true indicates that the  dialer supports the modem carrier signal, and
     uucico  therefore  will  require  that  that  carrier  be  on.   false
     indicates that  the dialer does not support  the modem carrier signal,
     and uucico therefore will not wait for it.

carrier-wait seconds
     Wait seconds for the carrier signal.  The default is 60.

dtr-toggle true|false [ true|false ]
     If the first argument is true,  toggle DTR before using the modem.  If
     the second argument is true, sleep for one second after toggling DTR.

complete-chat string ... string
complete-chat-timeout number
complete-chat-fail failure_string
complete-chat-seven-bit true|false
complete-chat-program program [ arguments ]
     These commands define  a chat script to be run  after the UUCP session
     has run to completion.   They are exactly like their chat counterparts
     described above.

abort-chat string ... string
abort-chat-timeout number
abort-chat-fail failure_string
abort-chat-seven-bit true|false
abort-chat-program program [ arguments ]
     These commands define a chat script  to be run if the UUCP session has
     aborted.   They are  exactly  like their  chat counterparts  described
     above.

complete string
abort string
     These  are  simplified  of  the  complete-  and  abort-  chat  scripts
     described above.   The former sends string to the  dialer after a call
     has completed  successfully; the latter sends its  string after a call
     has aborted.

protocol-parameter protocol parameter
     Set a  protocol parameter.   This command is  exactly the same  as its
     counterpart used  in file sys. For details, see  the Lexicon entry for
     sys.

seven-bit true|false
     When  your  system negotiates  the  protocol to  use  with the  remote
     system, force  your system to  accept only a protocol  that works over
     seven-bit connection.

reliable true|false
     When  your  system negotiates  the  protocol to  use  with the  remote
     system, force your system to accept only a protocol that works over an
     unreliable connection.

half-duples true|false
     If true, then  the dialer supports only half-duplex connections.  This
     forces your  system to  avoid bidirectional protocols  during protocol
     negotiation.

Example

The following gives the entry for a 9600-baud Trailblazer modem:

    dialer tbfast
    chat "" AT\sE0\sQ4\sV1\sS7=60\sS50=255\sS51=255\sS66=0 \
        \sS111=30\sDP\D CONNECT\sFAST
    chat-timeout 60
    chat-fail BUSY
    chat-fail NO\sCARRIER
    chat-fail NO\sANSWER
    abort-chat "" \d+++\dATH0\sV0\sE0\sQ1\sS0=1
    abort-chat "" \d+++\dATH0\sV0\sE0\sQ1\sS0=1

Most of  the commands in this  example are optional.  A  dialer entry could
work  with  only the  first  two commands.   The  following describes  each
command in detail:

dialer    Give the dialer the name tbfast.

chat      Give the chat script  with which uucico converses with the modem.
          It sets  a number of  `S' registers, turns echoing  off, puts the
          modem into  verbose mode, dials the  remote system, and indicates
          that the signal for success is the string CONNECT FAST. Note that
          normally  the  chat  script must  be  one  unbroken string;  this
          example is  broken into two lines  so it will fit  onto the page.
          For information on the  commands from which you would construct a
          chat script, see the documentation that comes with your modem.

chat-timeout
          Tells uucico how long to wait before it times out.  In this case,
          wait 60 seconds.

chat-fail Define a string with  which the modem indicates failure.  In this
          case,  there are  three such  commands,  each naming  a different
          message.

abort-chat
abort-chat
          These  give the  strings to  send to  the modem  in the  case of,
          respectively,  the successful  completion of  call or  an aborted
          call.  For this entry, the same string is send in either case: it
          turns off echoing and verbose mode, and turns on auto-answering.

See Also

Administering COHERENT,
port,
sys,
UUCP

Notes

Only the superuser root can edit /usr/lib/uucp/dial.

The  file dial  supports many  commands in addition  to the  ones described
here.  This  article describes  only those commands  that might be  used in
typical UUCP  connections.  For more  information, see the  original Taylor
UUCP documentation, which is in the archive /usr/src/alien/uudoc104.tar.Z.

© 2012 by Stephen A. Ness