AUTOEXPECT(1)                                       AUTOEXPECT(1)

       autoexpect  -  generate  an  Expect script from watching a

       autoexpect [ args ] [ program args...  ]

       autoexpect watches you interacting  with  another  program
       and creates an Expect script that reproduces your interac-
       tions.  For straightline scripts,  autoexpect  saves  sub-
       stantial  time  over writing scripts by hand.  Even if you
       are an Expect expert, you will find it convenient  to  use
       autoexpect to automate the more mindless parts of interac-
       tions.  It is much easier to cut/paste hunks of autoexpect
       scripts  together than to write them from scratch.  And if
       you are a beginner, you may  be  able  to  get  away  with
       learning  nothing more about Expect than how to call auto-

       The simplest way to use autoexpect is to call it from  the
       command line with no arguments.  For example:

            % autoexpect

       By  default,  autoexpect  spawns a shell for you.  Given a
       program name and arguments, autoexpect  spawns  that  pro-
       gram.  For example:

            % autoexpect ftp

       Once  your  spawned program is running, interact normally.
       When you have exited the shell (or program that you speci-
       fied),  autoexpect  will  create a new script for you.  By
       default, autoexpect writes the new script to "script.exp".
       You  can  override this with the -f flag followed by a new
       script name.

       The following  example  runs  "ftp"  and
       stores the resulting Expect script in the file "nist".

            % autoexpect -f nist ftp

       It  is  important  to  understand that autoexpect does not
       guarantee a working script because it necessarily  has  to
       guess  about  certain things - and occasionally it guesses
       wrong.  However, it is usually very easy to  identify  and
       fix these problems.  The typical problems are:

              o   Timing.   A  surprisingly  large number of pro-
                  grams (rn, ksh, zsh, telnet, etc.) and  devices
                  (e.g.,  modems)  ignore  keystrokes that arrive
                  "too quickly" after prompts.  If you find  your
                  new script hanging up at one spot, try adding a
                  short sleep just before the previous send.

                  You can force this behavior throughout by over-
                  riding  the  variable "force_conservative" near
                  the beginning of the  generated  script.   This
                  "conservative"  mode makes autoexpect automati-
                  cally pause briefly (one  tenth  of  a  second)
                  before  sending  each character.  This pacifies
                  every program I know of.

                  This conservative mode is useful  if  you  just
                  want  to  quickly  reassure  yourself  that the
                  problem is a timing one (or if you really don't
                  care  about  how  fast  the script runs).  This
                  same mode can be forced before  script  genera-
                  tion by using the -c flag.

                  Fortunately,  these timing spots are rare.  For
                  example, telnet ignores characters  only  after
                  entering  its  escape  sequence.   Modems  only
                  ignore characters immediately after  connecting
                  to  them  for  the  first time.  A few programs
                  exhibit this behavior all the  time  but  typi-
                  cally  have  a switch to disable it.  For exam-
                  ple, rn's -T flag disables this behavior.

                  The following example starts autoexpect in con-
                  servative mode.

                       autoexpect -c

                  The  -C  flag defines a key to toggle conserva-
                  tive mode.  The following example starts  auto-
                  expect  (in  non-conservative  mode) with ^L as
                  the toggle.  (Note that the ^L is entered  lit-
                  erally - i.e., enter a real control-L).

                       autoexpect -C ^L

                  The following example starts autoexpect in con-
                  servative mode with ^L as the toggle.

                       autoexpect -c -C ^L

              o   Echoing.  Many program  echo  characters.   For
                  example,  if  you  type "more" to a shell, what
                  autoexpect actually sees is:

                       you typed 'm',
                       computer typed 'm',
                       you typed 'o',
                       computer typed 'o',
                       you typed 'r',
                       computer typed 'r',

                  Without specific knowledge of the  program,  it
                  is impossible to know if you are waiting to see
                  each character echoed before typing  the  next.
                  If  autoexpect sees characters being echoed, it
                  assumes that it can send them all  as  a  group
                  rather  than  interleaving  them  the  way they
                  originally appeared.   This  makes  the  script
                  more  pleasant to read.  However, it could con-
                  ceivably be incorrect if you really had to wait
                  to see each character echoed.

              o   Change.   Autoexpect  records  every  character
                  from the interaction in the  script.   This  is
                  desirable  because  it gives you the ability to
                  make judgements about  what  is  important  and
                  what can be replaced with a pattern match.

                  On  the  other  hand, if you use commands whose
                  output differs from run to run,  the  generated
                  scripts are not going to be correct.  For exam-
                  ple, the "date" command always produces differ-
                  ent  output.   So  using the date command while
                  running autoexpect is a sure way to  produce  a
                  script  that  will require editing in order for
                  it to work.

                  The -p flag puts autoexpect into "prompt mode".
                  In this mode, autoexpect will only look for the
                  the last line of program output - which is usu-
                  ally the prompt.  This handles the date problem
                  (see above) and most others.

                  The  following  example  starts  autoexpect  in
                  prompt mode.

                       autoexpect -p

                  The  -P  flag  defines  a  key to toggle prompt
                  mode.  The following example starts  autoexpect
                  (in  non-prompt  mode)  with  ^P as the toggle.
                  Note that the ^P is entered literally  -  i.e.,
                  enter a real control-P.

                       autoexpect -P ^P

                  The  following  example  starts  autoexpect  in
                  prompt mode with ^P as the toggle.

                       autoexpect -p -P ^P

       The -quiet flag disables informational  messages  produced
       by autoexpect.

       The  -Q  flag names a quote character which can be used to
       enter characters that autoexpect would  otherwise  consume
       because they are used as toggles.

       The  following  example shows a number of flags with quote
       used to provide a way of entering the toggles literally.

            autoexpect -P ^P -C ^L -Q ^Q

       I don't know if there is a "style" for Expect programs but
       autoexpect  should  definitely not be held up as any model
       of style.  For example, autoexpect uses features of Expect
       that  are  intended  specifically  for  computer-generated
       scripting.  So don't try to faithfully write scripts  that
       appear  as  if they were generated by autoexpect.  This is
       not useful.

       On the other hand, autoexpect scripts do show some  worth-
       while  things.   For  example,  you can see how any string
       must be quoted in order to use it in a Tcl  script  simply
       by running the strings through autoexpect.

       "Exploring  Expect:  A  Tcl-Based  Toolkit  for Automating
       Interactive Programs" by Don Libes, O'Reilly  and  Associ-
       ates, January 1995.

       Don Libes, National Institute of Standards and Technology

       expect  and autoexpect are in the public domain.  NIST and
       I would appreciate credit if these programs  or  parts  of
       them are used.

                           30 June 1995                         1