CP/M/CPM_CDROM.iso/jsage/znode3/z3doc/tlib.lbr/TLIB.DZC/TLIB.DOC

Text File | 1993-06-07 | 16.8 KB | 350 lines

TLIB.DOC
  by Rick Charnes, San Francisco, November 18, 1986

      This is my second, and favorite, ALIAS I've written
that can be used to type out member files within a library -
straight ASCII, squeezed, or crunched.  (The other was TLF.COM)
They both came into being when I realized that with the growing
popularity of Steven Greenberg's CRUNCH file compression
algorighm NULU could no longer be relied upon to deal with
libraries, missing as it is a capability to deal with files of
this sort.

      Syntax is simple.  Make sure TLIB.COM, TLIB2.COM, and
EXIT.COM are all on your disk, and type:

                  TLIB [DU:] <libraryname>

VERY IMPORTANT:
(NOTE NECESSARY SPACE BETWEEN OPTIONAL DU: AND <LIBRARYNAME>

(note also: until Master Greenberg comes up with a full Z-System
version of TYPELZ that supports named directories, [DU:] here can
only be drive/user and not an NDR.)

      When an exit is desired, type 'BYE' at the "FILE TO TYPE"
prompt.

     --> Some changing of terminal escape sequences in TLIB.COM,
TLIB2.COM, and EXIT.COM may be necessary.  My apologies for
releasing something with non-standardized elements.  In TLIB.COM
I use ESC ) for half intensity, ESC ( for normaly intensity.  In
TLIB2.COM I use <ESC>G8 for underlining and <ESC>G0 turns it off,
and in EXIT.COM <ESC>G4 turns on reverse video and this also
turns off with <ES>G0.  You should set your own or change it to
whatever you like -- blink, reverse video, dim, etc.  These
changes are best done with BALIAS.  <ESC> is created by hitting
CTL-P, then the ESC key.  See (way) below for more info.

        A program of this nature is most important when dealing
with *.LBR's containing a large number of crunched files in that
TLIB returns you a directory of the library after you've
finished reading each file.  Hence you're not continually having
to do a DIR or otherwise listing the contents within the library
when moving from reading one file to another.  I very much enjoy
some of the new library "shell" programs coming out for their
advanced features and ease of use.   But, e.g., I recently
downloaded a library of 12 (!) text files, all crunched.  I
DEFINITELY want to have displayed for me in this situation a
directory of all the files immediately and automatically after
reading each member.

        For a long time I was using NULU in its regular "NULU
mode", and I would be faced with the same problem --- having to
constantly do a "-L" to list out the files in the library so that
I could choose which I wanted to read or otherwise act upon.
Then I discovered its "F"=Filesweep mode which operates like
NSWP.  Here you essentially have a listing/directory of the files
in front of you, and you choose your command to act on each as
you prefer.  This of course is ideal.  But until that happy day,
programs like TLIB are, for me at least, crucial. How do other
people deal with libraries of many members, all crunched, without
extracting them?


 ***************************************************************
 *                                                             *
 *  What follows is more of an excursion into my own learning  *
 *  process in writing this, complete with appropriate         *
 *  philosophical commentary where appropriate than a true,    *
 *  minimalist doc file, so you're welcome to proceed at your  *
 *  own risk -- uh, speed.            - Rick Charnes           *
 *                                                             *
 ***************************************************************



One learns best when answering one's own questions...

                      *      *       *

     "Could someone explain VALIAS' "recursive" mode to me?
     I just don't get it."

        Thus went the message I sent to Z-Node Central perhaps two
weeks ago, and as sadly is too often the case on 8-bit BBS's in
these days of the dominance of the IBM behemoth, it went
unanswered.  So...encouraged by accidentally stumbling across the
VALIAS doc file --- I'm not really sure how I ever missed it
before -- I taught myself about VALIAS recursion, and it has
greatly fueled my Z-imagination.  No doubt had I learned from
someone else the power of it all wouldn't have hit so well.  Many
thanks to VALIAS author Jay Sage, who has actually returned phone
messages to San Franciso I have left with his family for his
generosity, friendliness, warmth, and overall good Samaritanship
in providing the emotional support and software tools to make
being a beginning Z3-er like myself an overwhelmingly pleasurable
and exciting experience.

      All this by way of introduction to my release of my alias
TLIB.COM, an example of the use of VALIAS' recursive mode.  TLIB,
continuing in the tradition started by Echelon's GLF, is a way of
entering a library and then viewing multiple files inside it,
especially valuable if they are crunched and not otherwise
accessible via ordinary tools.  Until NULU is updated to include
the capacity to uncrunch library members, we need to rely on
aliases like this or Terry Carroll's ZLBR10A.COM.  I have too
often entered a library with NULU only to find the DOC file
and/or source file is crunched, thus precluding the use of NULU.

      TLIB is similar to my previous TLF.COM, except that the
libary directory automatically and by default displays after you
have finished reading a library member.  Since TLF, I have still
been slightly annoyed with the way you had to hit <CR> to get the
library directory displayed back on your screen after viewing a
file within a library.  TLF returns you to the CMD.COM prompt at
which point you can exit the ALIAS with SHCTRL P, or anything
else to see the directory again.  But I always wanted to the
directory to come up IMMEDIATELY after the viewing of a library
member without my having to do anything; I wanted it to be the
default.

      I'm sure there are umpteen ways to do this, but I always
try to take the path by which I will learn the most, and VALIAS'
recursive mode seemed to be a very good teacher.  Briefly, this
mode permits you in a sense a "GOTO START" label within an alias.
It permits you to loop indefinitely back to the beginning without
overloading the multiple command buffer.  Or it can be used
in the same vein as I have here to loop back and forth between
several different ALIASes, again without the looping causing the
dread command buffer overflow.  It "cleans out" all superfluous
commands.  So I figured it would be a perfect way to immediately
come back to display the library directory after typing a file.

      But then there always arises the question of how to exit
the loop when you wish to.  Unfortunately, one cannot exit from
TLIB with a CTL-C like you can from a ZEX script.  So, studying
and re-studying my RESOLVE documentation, I put my bet on a long
shot: what were the chances RESOLVE could properly deal with a
flow command? I wasn't sure, but I tried it:


                         TLIB2.COM (the body of the program)
                         ----------

ECHO ])G8 * DIRECTORY OF $1.LBR *  G0

LLF $2$1                      ;Displays the library directory.
GETVAR TLIB FILE TO TYPE?     ;Gets the variable, names it %TLF.
RESOLVE IF %TLIB=BYE          ;WOULD THIS WORK? If the user
                              ;enters 'BYE', then go to ....
EXIT                          ;ANOTHER Alias, called EXIT, which
                              ;exits the user back to ZCPR3.
ELSE
RESOLVE TYPELZ $2$1 %TLIB     ;..or else type the library file.
TLIB2 $1 $2                   ;Here's the recursion.  Return to
                              ;initial ALIAS TLIB.COM, display
                              ;a directory, and pass the
                              ;parameters, please
FI


      It worked!  RESOLVE.COM properly resolves the IF/%TLF
combination.   If the user replies 'BYE' at the "FILE TO TYPE?"
prompt, s/he is then sent to the alias EXIT.COM which exits the
entire alias network and returns the user to the friendly skies
of ZCPR3.

      I made TLIB a 3-alias network for an important and
necessary reason.  The initial TLIB alias does nothing but set
the quiet flag then send the user to TLIB2, the body of the
thing.  Deferring to the noble and time-honored ZCPR3 alias
tradition, I have also added the classical help file/syntax
format (IF NULL $1 and IF $1=//) with some pretty dim/normal
intensity graphics included therein.  Terribly sorry if your
terminal doesn't take "ESC-)" for dim intensity; this program,
like so many others, started out as something to play around
with for myself that looked nice.  I know releasing something
non-standard like this is not kosher.  I've always thought,
however, the art of public domain programming is to do as many
non-kosher things as you possibly can and need to in order to
have fun and learn as much as possible.  I know I passed that
test with this.  Please change it to your terminal's sequences.

                              TLIB.COM:
                              --------
                              QUIET S
                              TLIB2 $1 $2

The reason I made a separate ALIAS for this - besides needing
room in the MCL buffer for the syntax scripts - is that if I set
the command line 'QUIET S' in the same alias as the rest of the
commands the alias would forever be coming across this line and
setting the quiet flag on each pass.  This is of course totally
unnecessary and a waste of time, so I'm letting it do it once and
then forget about it.  And of course EXIT.COM, the third in the
trio, resets quiet. This use of an "multi-alias network" is the
best substitute I can figure out for the 'GOTO <label>'
capability I _wish_ ALIASes had.

      By the way, it's instructive to try these files out setting
them in normal, rather than recursive, mode just to see what
happens.  At some point, usually after about the third file
you've asked TLIB to type, you're *BEEP*ed, sent into EXIT.COM,
and exited out of the program.  What's going on is that, just as
Jay Sage says will happen, the MCL (what? you don't yet know that
ZCPR lingo for 'multiple command line'?) buffer fills up past
that magic 204 character capacity, the flow control network gets
all confused, the ZCPR3 God throws up his hands, and says, "Out,
infidel!"

      Comments on why I _start_ TLIB2.COM with "FI" rather than
ending it that way, as is the usual:

      I had initally made "FI" the second to last command in the
alias, just before the recursive "TLIB2 $1 $2" command which
should be the last command in the alias.  This "FI" should be
there of course to flush the IF level to 0, before the alias runs
again.  But for some reason that PERHAPS God knows, when I did
that, and then I'd enter 'BYE' I would be given the "RETURNING TO
ZCPR3..." message ---- AND THE ALIAS WOULD START AGAIN!!  Don't
ask me what's going on.  So I figured maybe it's because the IF
LEVEL is not getting flushed (set back to 0).  So I went into
EXIT.COM and put in an 'XIF' command --- to no avail.  The alias
would still repeat when I tried to exit.

      So then I put "FI" as the very last command and that worked
fine.  Until I realized that upon exit from the whole alias
network the IF level was set to a number corresponding to how
many files had been viewed.  And of course --- the 'FI' was never
being reached to reset the level back to 0.

      So I put it at the beginning, it gets reset each time
before it even starts, and everyone's happy.

      IF levels are a trip.  I hope people have fun using
IFSTAT.COM.  I like to abort ZEX scripts and the like in the
middle and otherwise deliberately set the IF level to
some ridiculously high level just to watch what goes on.  There's
something philosophically amusing about thinking of something
existing in a state of (trombones here...) "IF LEVEL 6."  One can
pity a ZCPR3 system having to go through an experience like that.
I mean can YOU imagine living at an IF level of 6?   The _awful_
sense of insecurity..."Um, if this,,,,and if that....and if the
other thing, and if, if, if, and if ...."

      Speaking of slowing things down, the only reason I have to
use a separate alias for the EXIT is because as of the present
state of ZCPR3 flow control, the syntax "~=" (does not equals) is
not implemented.  If that were possible, I could have done:

     RESOLVE IF %TLIB~=BYE
     RESOLVE TYPELZ $1 %TLIB
     TLIB2 $1 $2
     FI

and then if %TLIB _did_ equal 'BYE' it would just ignore the IF
loop and you'd be happily booted out right away.  The alias would
be shorter and run much quicker.

      I think my method of allowing DU: designation on the
command line is kind of ingenious.  Aw, come on, give me a break:
when you're a beginner in this stuff and something works it
always feels ingenious.  I make you use two parameters, though.
You just have to make sure you put a space between the DU: and
the library name, so the alias understands them as two
parameters. If you don't enter a DU: that's OK too and TLIB
doesn't mind. It just ignores any reference to $2 in the command
line and uses $1 as the library name.  If you enter both, $1 is
the DU: and $2 becomes the library name.


                  *            *            *


      I'd like also to draw fellow Z enthusasiasts' attention to
my use of the ECHO command to send terminal attribute escape and
other sequences to the terminal to create attractive displays.
This is something I've been doing quite a bit of, and am very
pleased with this capability of ZCPR3.  Now of course each
terminal's codes will be different.  <ESC G 8> sets underlining
on my Qume 102A, and <ESC G 0> turns it off, but you should set
it according to yours.  Also nice is reverse video with <ESC G 4>
My command line

            ECHO ])G8 * DIRECTORY OF $1.LBR *  G0

underlines the text, but it also does something else.  My
terminal uses standard (what? standards in 8-bit machines?) ADM-
3A-type cursor coordinate addressing, so I use ECHO again, this
time to send an escape sequence to position the cursor more
towards the center of the screen.   The sequence

                         <ESC> ] )

tells my terminal to position the cursor to column 10 on the
current line.  ")" here equals "10" in terminal code.  If I
wanted ZCPR3 to display some text on line 6, column 24, I would
do
                     ECHO <ESC>=%7this is my text

The way you get VALIAS or BALIAS to insert an <ESCAPE> code is by
pressing CTL-P first, then hit your escape key.  It will appear
on your screen as a dim video "]" when using BALIAS, and as "^]"
in VALIAS.  You can also send line feeds and carriage returns in
your ECHO text by, again, pressing CTL-P first, then CTL-J and/or
CTL-M.  I often do this if I want to space my text with nice
clean blank lines.  I did this in TLIB.COM for the help/syntax
message.  This will only work, however, in BALIAS and not in
VALIAS.  VALIAS doesn't seem to have a "literal" mode for
carriage return and line feed with CTL-P.  So to change TLIB.COM,
perhaps to change the intensity attributes, you'll have to use
BALIAS (I've never used TALIAS).  Once you've put ^J's into an
alias, VALIAS' line numbering gets all screwed up and you
shouldn't even hope to try to use it.

     Also in VALIAS only, when you do your CTL-P's to enter an
<ESC> code, be prepared to have your printer turned on as a side
effect.  No problem --- just do a second CTL-P to turn it off.
This second CTL-P won't get entered into your alias.

      I do a lot of this cursor positioning and find it an
excellent way to pretty up otherwise drab program display.

      One thing I forgot about VALIAS' recursive mode.  I don't
know about other folks, but I will often switch back and forth
between VALIAS and BALIAS in the course of a creating, working
on, and editing an alias.  Each does a certain set of things
best.  If, however, you're using VALIAS to create a recursive
alias, if you then go and edit it with BALIAS, this will "de-
recursify" it.  It apparently takes out or resets the flag or
byte with which VALIAS had previously set it.  If you do this ---
and I often find I must -- that's ok.  Just make sure that the
very last thing you do before you're ready to run the alias is to
edit it in VALIAS and set the recursive flag.  Any changes that
BALIAS did to it will be remedied.

      Have fun with TLIB and leave me a message if you have any
comments.

Rick Charnes, San Francisco, California
President, Bay Area (Morrow) Micro Decision Users Association

Home BBS'es:
Z-Node Central 415/489-9005
BAMDUA BBS 415/654-3882
ent, Bay Area (Morrow) Micro Decision Users Association

Home BBS'es:
Z-Node Central 415/489-9005
BAMDUA BBS