autoexpect man page on Oracle

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       autoexpect - generate an Expect script from watching a session

       autoexpect [ args ] [ program args...  ]

       autoexpect  watches you interacting with another program and creates an
       Expect script that  reproduces  your  interactions.   For  straightline
       scripts,	 autoexpect  saves  substantial	 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 interactions.  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

       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 program.  For example:

	    % autoexpect ftp

       Once your spawned program is running, interact normally.	 When you have
       exited the shell (or program that you specified), autoexpect will  cre‐
       ate 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:

	      ·	  Timing.   A  surprisingly large number of programs (rn, ksh,
		  zsh, telnet, etc.) and devices (e.g.,	 modems)  ignore  key‐
		  strokes  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 overriding the
		  variable "force_conservative" near the beginning of the gen‐
		  erated  script.   This  "conservative" mode makes autoexpect
		  automatically pause briefly (one tenth of a  second)	before
		  sending  each character.  This pacifies every program I know

		  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 generation by using
		  the -c flag.

		  Fortunately, these timing spots are rare.  For example, tel‐
		  net  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  typically  have  a
		  switch  to  disable  it.  For example, rn's -T flag disables
		  this behavior.

		  The following	 example  starts  autoexpect  in  conservative

		       autoexpect -c

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

		       autoexpect -C ^L

		  The following example starts autoexpect in conservative mode
		  with ^L as the toggle.

		       autoexpect -c -C ^L

	      ·	  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 conceivably be incorrect if you really had
		  to wait to see each character echoed.

	      ·	  Change.   Autoexpect records every character from the inter‐
		  action 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 example, the "date"  command  always  produces
		  different  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 usually 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  fol‐
		  lowing  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  charac‐
       ters  that  autoexpect would otherwise consume because they are used as

       The following example shows a number of flags with quote used  to  pro‐
       vide 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 use‐

       On the other hand, autoexpect scripts do show some  worthwhile  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  Pro‐
       grams" by Don Libes, O'Reilly and Associates, 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			 AUTOEXPECT(1)

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