Ubuntu Manpage: dfrotz - interpreter for Infocom and other Z-Machine games (dumb interface)

NAME

       dfrotz - interpreter for Infocom and other Z-Machine games (dumb interface)

SYNOPSIS

       dfrotz [options] file [blorb_file]

       At  least  one  file must be specified on the command line.  This can be either a plain Z-
       code file or a Blorb file.  A Z-code file is a compiled executable for the  Z-Machine.   A
       Blorb  file  contains audio, graphics, and other things in addition to the game wrapped up
       into a single file.  It can also optionally contain the Z-Machine executable.  If a  plain
       Z-code  file  is  supplied, then Frotz will check for a Blorb file with the same base name
       but an extension of .blb, .blorb, or .zblorb and load it if found.

       If the file supplied on the command line is a Blorb file, then Frotz will check to see  if
       a Z-code file is contained within.  If not found, then Frotz will complain and exit.

       An  alternatively-named Blorb file can be supplied as the optional second parameter to the
       command line invocation.

DESCRIPTION

       Frotz is a Z-Machine interpreter.  The Z-machine is a virtual machine designed by  Infocom
       to  run  all  of  their  text  adventures.   It went through multiple revisions during the
       lifetime of the company, and two further revisions (V7 and  V8)  were  created  by  Graham
       Nelson  after  the company's demise.  The specification is now quite well documented; this
       version of Frotz supports version 1.0.

       This version of Frotz fully supports all  these  versions  of  the  Z-Machine  except  for
       version 6.  Version 6 is semi-supported by displaying the outlines of V6 graphics with the
       picture number in the bottom-right corner.

       This manpage is for Frotz with the dumb interface.  Dumb Frotz  does  not  support  sound-
       effects, graphics, or colors.

OPTIONS

-a Watch attribute setting. Setting and clearing of attributes on objects will be
noted in debugging messages.

-A Watch attribute testing. Every time the Z-machine tests an attribute value, the
test and the result will be reported.

-f [irc | ansi | normal]
Select type of format codes. Dumb Frotz can optionally mark up its output with
codes for color, bold, underline, and so on. Currently, formatting codes for irc
clients and ansi terminals are supported. Specifying normal or not using this flag
at all will result in Dumb Frotz's normal behavior of not using any sort of markup.

-h N Text height. Every N lines, a MORE prompt will be printed. Use of the -m option
renders this option moot.

-i Ignore fatal errors. If a Z-Machine interpreter encounters a zcode error such as
division-by-zero or addressing an illegal object, the proper response is to abort
execution. This is done because the zcode program doesn't have a clear idea of
what is going on. There are some games out there that cause fatal errors because
the authors were careless and used an interpreter that didn't properly check for
errors. This option is intended to get around such bugs, but be warned that
Strange Things may happen if fatal errors are not caught.

-I N Set the interpreter number. Infocom designed the Z-machine such that a game could
tell on what kind of machine the interpreter was running. See INTERPRETER NUMBER
below.

-L <filename>
When the game starts, load this saved game file.

-m Turn off MORE prompts. This can be desirable when using a printing terminal.

-o Watch object movement. This option enables debugging messages from the interpreter
which describe the moving of objects in the object tree.

-O Watch object location. These debugging messages detail the locations of objects in
the object tree.

-p Plain ASCII output only. This inhibits the output of accented letters and other
characters from the Latin-1 character set, replacing them with reasonable
alternatives. This may be necessary on devices lacking these characters. The
OE/oe dipthongs are missing from the Latin-1 set. These are handled as well.

-P Alter the piracy opcode. The piracy opcode was never used by Infocom. This switch
is really only useful for those who like to toy around with Z-code.

-q Quiet mode. Suppress startup messages such as "Loading zork1.z3".

-r xxx Set runtime options. This option may be used repeatedly. See CONFIGURATION below.
There is no need to prepend a backslash.

-R <path>
Restricted read/write. Reading and writing files will be restricted only to the
provided path. Ordinarily Frotz will write or read its saves, transcripts, and move
recordings in whatever path or directory the user provides when the SAVE, SCRIPT,
or RECORDING commands are given. This can be undesirable if Frotz is run in a
restricted environment, by a front end, or by a chatbot. This option will cause
Frotz to write or read only to the provided path and nowhere else. Then the
controlling process can then watch that directory for changes and need not worry
about someone scribbling or snooping who-knows-where.

-s N Set the random number seed value. The given seed value is used as the initial seed
value on every restart. This is helpful for testing games like Curses which make
random decisions before the first input (such that the hot key Alt-S does not
really help).

-S N Set the transcript width. By default your transcript files are formatted to a
width of 80 columns per line, regardless of the current text width. This switch
allows you to change this setting. In particular, use -S 0 to deactivate automatic
line splitting in transcript files.

-t Sets the Z-machine's Tandy bit, which may affect the behavior of certain Infocom
games. For example, Zork I pretends not to have sequels, and Witness has its
language toned down.

-u N Sets the number of slots available for Frotz's multiple undo hotkey (see below).
This defaults to twenty, which should be sufficient for most purposes. Setting too
high a number here may be dangerous on machines with limited memory.

-w N Manually sets the text width. This should not be necessary except in special
circumstances.

-x Expand the abbreviations "g", "x", and "z" to "again", "examine", and "wait". This
switch is for use with old Infocom games that lack these common abbreviations which
were introduced in later games. Use it with caution: A few games might use "g",
"x" or "z" for different purposes.

-v Show version information and exit. This will display the version of Frotz, some
information about what's enabled and what's not, the commit date of the source
code, and a git(1) hash of that commit.

-Z N Error checking mode.
0 = don't report errors.
1 = report first instance of an error.
2 = report all errors.
3 = exit after any error.
Default is 1 (report first instance of an error).

INTERPRETER NUMBER

       The interpreter number is a setting in the Z-machine header which is used to tell the game
       on what sort of machine the interpreter is running. Frotz will  automatically  choose  the
       most  appropriate  number  for a given Infocom-produced game.  Should you want to override
       the number, the -I option is available.

       An interpreter should choose the interpreter number most suitable for the machine it  will
       run  on.   In  Versions  up  to 5, the main consideration is that the behaviour of 'Beyond
       Zork' depends on the interpreter number (in terms of its usage of the  character  graphics
       font).  In Version 6, the decision is more serious, as existing Infocom story files depend
       on interpreter number in many ways: moreover, some story files expect to be  run  only  on
       the  interpreters  for  a particular machine.  There are, for instance, specifically Amiga
       versions.  The DECSystem-20 was Infocom's own in-house mainframe.

       For Infocom's four V6 games, the interpreter number will be automatically chosen based  on
       the title and release number.  Of course, this can be overridden at the command line.

       Infocom used the following interpreter numbers:

       1   DECSystem 20

       2   Apple IIe

       3   Macintosh

       4   Amiga

       5   Atari ST

       6   IBM PC

       7   Commodore128

       8   Commodore64

       9   Apple IIc

       10   Apple IIgs

       11   Tandy Color

CONFIGURATION

Unlike it's curses-using or SDL-using siblings, dfrotz does not use configuration files.
All configuration is done on the command line or while dfrotz is running.

General Commands
\help Show help message.

\set Show the current values of runtime settings.

\s Show the current contents of the whole screen.

\d Discard the part of the input before the cursor.

\wN Advance clock N/10 seconds, possibly causing the current and subsequent inputs to
timeout.

\w Advance clock by the amount of real time since this input started (times the
current speed factor).

\t Advance clock just enough to timeout the current input

Reverse-Video Display Method Settings
\rn none

\rc CAPS

\rd doublestrike

\ru underline

Output Compression Settings
\cn none: show whole screen before every input.

\cm max: show only lines that have new nonblank characters.

\cs spans: like max, but emit a blank line between each span of screen lines shown.

\chN Hide top N lines (orthogonal to above modes).

Misc Settings
\sfX Set speed factor to X. (0 = never timeout automatically).

\mp Toggle use of MORE prompts

\ln Toggle display of line numbers.

\lt Toggle display of the line type identification chars.

\vb Toggle visual bell.

\pb Toggle display of picture outline boxes.

(Toggle commands can be followed by a 1 or 0 to set value ON or OFF.)

Character Escapes
\\ backslash

\# backspace

\[ escape

\_ return

\< cursor-left

\> cursor-right

\^ cursor-up

\. cursor-down

\1..\0 f1..f10

\D..\X Standard Frotz hotkeys.

use \H (help) to see the list of hotkeys.

Line Type Identification Characters
Input lines (untimed)
> A regular line-oriented input

) A single-character input

} A line input with some input before the cursor. Use \d to discard it.

Input lines (timed)
T A regular line-oriented input

t A single-character input

D A line input with some input before the cursor. Use \d to discard it.

Output lines
] Output line that contains the cursor.

. A blank line emitted as part of span compression.

(blank) Any other output line.

UNICODE

       Dumb Frotz supports Unicode glyphs by way of UTF-8 if the terminal  used  supports  UTF-8.
       If  you  prefer  using  xterm,  start it as uxterm.  This is a wrapper script that sets up
       xterm with UTF-8 locale.  You can also manually tell an xterm to switch into UTF-8 mode by
       holding  CTRL  and the right mouse button to bring up the VT FONTS menu.  Depending on how
       xterm was installed, you may see an option for "UTF-8 Fonts" which will allow  Unicode  to
       be properly displayed.

       Getting  normal  xterm  to  behave  like this all the time can vary from system to system.
       Other terminal emulators have their own ways of being set to use UTF-8 character encoding.

       If you are using some sort of wrapper around dfrotz, and want to make use of  Unicode,  it
       is the responsibility of the wrapper to make sense of characters passed back and forth.

NON ASCII CHARACTERS

       Non-ASCII  glyphs  can  be  displayed without the use of UTF-8 by way of the ISO-8859-1 or
       ISO-8859-15 (Latin-1 or Latin-9) character sets.  ISO-8859-15 is more or less identical to
       ISO-8859-1  except  that  the OE/oe dipthongs are supported, replacing the seldom-used 1/2
       and 1/4 glyphs.  See also luit(1) charsets(7) iso_8859-1(7) and  iso_8859-15(7)  for  more
       information.

   LOCALE
       An important means of ensuring the system knows to use UTF-8 is to make sure the locale is
       set appropriately.  This is valid only when Dumb Frotz runs under Unix-ish systems.

       Using the command locale will tell you what is currently in use.  Using locale -a

       will show you what's available.  Then set your LANG  evironmental  variable  to  something
       appropriate by using one of these commands:

           export LANG=C.UTF-8
           export LANG=en_US.utf8

       This  can  be put in your shell configuration file, be it .profile, .bash_profile, .login,
       .bashrc, or whatever.

       It can also be set system-wide in the equivalent files in /etc.

   SEE ALSO
       ash(1) bash(1) csh(1) ksh(1) sh(1) zsh(1)

ENVIRONMENT

       Unlike it's curses-using or SDL-using siblings, dfrotz does not search any path  for  game
       files.

FURTHER INFORMATION

       The Frotz homepage is at https://661.org/proj/if/frotz/.

       A  git(1)  repository  of  all versions of Unix Frotz back to 2.32 is available for public
       perusal here:
       https://gitlab.com/DavidGriffith/frotz/.

       The bleeding edge of Frotz development may be followed there.

       Source tarballs are available at the IF Archive or any of its many mirrors:
       http://www.ifarchive.org/

       Most distributions of Linux and BSD include Frotz in their package repositories.

       It is distributed under the GNU General Public License version 2 or (at your  option)  any
       later version.
       https://www.gnu.org/licenses/gpl-2.0.en.html

       This  software is offered as-is with no warranty or liability.  If you find a bug or would
       like Frotz to do something it doesn't currently do, please visit the above Gitlab  website
       and report your concerns.

CAVEATS

       The Z Machine itself has trouble with the concept of resizing a terminal.  It assumes that
       once the text height and width are set, they will never change; even across  saves.   This
       made  sense  when  24x80 terminals were the norm and graphical user interfaces were mostly
       unknown.  I'm fairly sure there's a way around this problem, but for now, don't resize  an
       xterm  in which frotz is running.  Also, you should try to make sure the terminal on which
       you restore a saved game has the same dimensions as the one on which you saved the game.

       This manpage is not intended to tell users HOW to play interactive fiction.  Refer to  the
       file  HOW_TO_PLAY  included  in the Unix Frotz documentation or visit one of the following
       sites:
       http://www.microheaven.com/ifguide/
       http://www.brasslantern.org/beginners/
       http://www.musicwords.net/if/how_to_play.htm
       http://ifarchive.org/

BUGS

       This program has no bugs.  no bugs.  no bugs.  no *WHAP*  thank  you.  If  you  find  one,
       please report it to the Gitlab site referenced above in FURTHER INFORMATION.

AUTHORS

       Frotz was written by Stefan Jokisch for MSDOS in 1995-7.
       The Unix port was done by Galen Hazelwood.
       The Unix port is currently maintained by David Griffith <dave@661.org>.