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Text File | 1992-12-27 | 24KB | 597 lines

          _ __  _   _ __ _ __
         // /  //| // || \\|     N E W S
        //_/  // |//  ||  |\\    Vol 2, Issue 4 - August 1991
         R o u n d T a b l e

   Items of interest to participants of the GEnie Unix RoundTable

      The RoundTable SysOps are:
      Dave Weinstein......OLORIN     Brian Riley.........DELPHI
      Gary Smith..........GARS       Chris North-Keys....HARP
      Rick Mobley.........LRARK    All Unix SysOps.....UNIXSYSOPS$
   We strongly encourage you to contact any or all of us if you have -ANY-
 comments or suggestions. This is -YOUR- RoundTable. We are here to make
 your participation as pleasant and beneficial as possible.

 ED: editor notes - Chocolate Friendly Interface:
 --                 editorial note from Dave Weinstein

 Is there something about the Unix RoundTable that isn't quite right?
 Or is Unix just driving you to distraction...

 While we hope that you'd write us at UNIXSYSOPS$ with any problems, comments
 or suggestions, there is also another alternative...

 Unix RT Sysop Dave Weinstein will be participating in the Chocolate Pie
 Throw at this year's FidoCon in Denver... So throw a pie for a good cause,
 and fondly remember all the wonderful little things about Unix that were
 so much fun to encounter for the first time!
 --

 Using the Korn Shell (ksh)     Using KSH made a LOT easier. Gary (GARS)
 --------------------------

 Ron Heiby, moderator of mod.os.unix dusted off some old notes on using
 the Korn Shell that have not aged a bit. ksh is gaining in popularity
 so this piece is a definite keeper. Gary (GARS)

 If my records are complete, I posted the this article in December of
 1986, while working for AT&T.  Then, with modifications in December of
 1987, while working for Motorola.  Since then, Ksh-88 has been
 released and I've seen quite a few articles asking to do lots of stuff
 with the prompt string.  So, here it is again, modified for Ksh-88 a
 bit and enhanced in some other minor ways.  If you are still using an
 older version of Ksh, UPGRADE!  Enjoy!

 A while ago [from the perspective of someone writing in December of
 1986], there were several messages posted to Usenet which showed ways
 to include various information into a Korn Shell PS1 prompt.  I
 thought that a number of these were real clever and incorporated them
 into my own environment.

 Now that Motorola Microcomputer Division [now the Motorola Computer
 Group] is selling the Korn Shell for our Delta Series of 68020-based
 systems, I thought I'd share this generally.

 Relatively little here is my own invention, but I can no longer say
 who had every idea.  I did put a lot of work into integrating
 everything together so that it would all work in a coordinated
 fashion.  The time stamp stuff is from Korn.  The "autoload" stuff
 [originally used] for functions (pshd, popd, etc.) as well as the
 original versions of those functions is from a Usenet article by Avi
 E. Gross in 10/84.  [This has since been absorbed in slightly
 different form into standard Ksh-88.]  I have made some readability
 and efficiency enhancements to the originals, as well as merging them
 into the rest of the stuff here.  I pulled out the large blocks of
 comments in Avi's original to improve the performance in my running
 copy and keep the original intact elsewhere so I can figure out what's
 going on.  As to the prompt-resetting code, I know there were at least
 three different people (plus me) who contributed to what is merged
 together here, but I lost the original Usenet articles.  Thanks,
 whoever you are.

 I've tried to put this is into a form that you can easily install into
 your own environment.  I mostly did it to see if I could.  Since then,
 it has proved useful enough for me to keep it as my normal
 environment.

 One could easily turn up one's nose at all this, if one really likes the "$ "
 prompt, as this is about as far from that as you can get.  The normal prompt
 when logged in and in your home directory is:    host: hh:mm:ss [~]
                         nn>
 After "cd /usr/src/cmd/vi", it is:        host: hh:mm:ss [src/cmd/vi]
                         nn>
 After "pshd /usr", it is:            host: hh:mm:ss 1: [/usr]
                         nn>
 After "popd", it is back to:            host: hh:mm:ss [src/cmd/vi]
                         nn>
 After invoking a sub-shell (ksh):        host: hh:mm:ss [src/cmd/vi]
                         nn>>

 The "host" is the output of the "uname" command.  I added the host
 name to the prompt to make it more obvious to whom I was "talking" in
 the face of "cu" and "rlogin" and windowing terminals.  The "nn" is
 the ksh history number.  hh:mm:ss is the time.  As you can see, up to
 the last three directories in your current directory are included.  If
 you are in a subdirectory of your home directory, your home directory
 path counts as a single directory and is represented with a tilde (~).
 If you are using Shell Layers (shl), the layer name "foo" or number
 "(n)" is displayed as part of the prompt, too.  If the uid of the user
 is 0 (root), then a pound sign (#) is used instead of a greater-than
 (>) to indicate nesting of sub-shells.  The prompt was split into two
 lines because the escape sequences to highlight a non-zero return code
 get counted as printable characters and so fewer characters from the
 command you are entering are visible in the line.

 Good luck trying to change any of it without breaking something else.
 I am currently running ksh "Version 11/16/88e".

 Even if you don't use this, it makes an interesting exercise to figure
 out how everything works.  After doing so, you'll have a very good
 understanding of ksh programming.

 Ron.

 --------- This goes in your .profile --------
 #    environment for fancy prompt
 export PSSHL PS1="!$ " FPATH=~/ksh

 -------- This goes in your $ENV file ---------
 # All this good stuff needed for interactive shells only.
 # Guard it with appropriate tests for better effeciency of startup.
 # Here's a good example of this:
 #    case "$-" in
 #    *c*)    # Stuff for -c, command line shells goes here.
 #        :
 #        ;;
 #    *)    # Stuff for for non -c, (interactive) shells.
 #        :
 #        ;;
 #    esac
 #
 #        Set prompt string portion for Shell Layers layer.
 TTY=$(tty)
 if [ "$TTY" != "${TTY#*sxt}" -a "${SHDEPTH:-}" = ">" ]
 then
     export PSSHL=$PS1
 fi
 unset TTY
 #
 #        Set System name string for fancy prompt
 UNAME=$(uname)
 #
 #        Set standout strings for fancy prompt
 : ${SMSO:=$(tput smso)} ${RMSO:=$(tput rmso)}
 #
 #        Set up for time stamping
 typeset -RZ2 _x1 _x2 _x3
 let SECONDS=$(date '+3600*%H+60*%M+%S')
 TIME='"${_d[(_x1=(SECONDS/3600)%24)==(_x2=(SECONDS/60)%60)==(_x3=SECONDS%60)]}$_x1:$_x2:$_x3"'
 #
 #        Define the replacement for the "cd" builtin
 function ch {
     if cd ${*:-''}
     then
         resetps1
     else
         return 1
     fi
 }
 alias cd=ch    # make it easy to use

 function resetps1 {
     typeset _dir=$PWD
     typeset _dirt=${_dir#$HOME}    # directory tail
     if [ "${_dirt}" != "${_dir}" ]
     then
         _dir="~${_dirt}"
     fi
     typeset front=${_dir%/*/*/*}
     : ${front:=x}
     case ${pushlevel:-0} in
     0)    PS1="${UNAME}: ${TIME} ${PSSHL:-}${SMSO:-}\${?#0}${RMSO:-}[${_dir#$front/}]
 !$SHDEPTH ";;
     *)    PS1="${UNAME}: ${TIME} $pushlevel: ${PSSHL:-}${SMSO:-}\${?#0}${RMSO:-}[${_dir#$front/}]
 !$SHDEPTH ";;
     esac
 }
 # Functions related to push and pop routines
 alias   dirs='echo "\t0: $PWD"' \
     popd='echo "You have never pushed any levels.\nYou remain at $PWD."'
 #
 #        Check for uid 0 (root)
 id=$(id)
 id=${id#uid=}
 id=${id%%\(*}
 if [ id -eq 0 ]
 then
     export SHDEPTH=${SHDEPTH:-}'#'
 else
     export SHDEPTH=${SHDEPTH:-}'>'
 fi
 # Set special colors
 case $TERM in
 mskermc)
     case $id in
     0)    color=37 ;;
     501)    color=31 ;;
     *)    color=35 ;;
     esac
     SMSO="[41;33m" RMSO="[44;${color}m[1m"
     unset color
     ;;
 tm229|tm229g)
     case $id in
     0)    color=33 ;;
     501)    color=37 ;;
     *)    color=35 ;;
     esac
     SMSO="[41;33m" RMSO="[40;${color}m[1m"
     unset color
     ;;
 *)
     ;;
 esac
 unset id
 resetps1

 -------- This is ~/ksh/pshd, linked to ~/ksh/pshpwd and ~/ksh/poppwd  ---------
 unalias popd dirs
 integer pushlevel=0

 function pshd
 {
     dirsave[pushlevel]="$PWD"        # save the name of the current dir
     promptsave[pushlevel]="$PS1"    # save the current prompt
     if [ pushlevel = 0 ]
     then
     pushprompt="$PS1"
     fi
     ch ${1:-$HOME} 2> /dev/null
     case $? in
       0)                # "cd" succeeded.
     let pushlevel=pushlevel+1
     pwd                # show the current directory
     : ${2:+`ls -Fx $3 $4 $5 $6 $7 $8 $9 >/dev/tty`}
     resetps1
     ;;
       *)                # "cd" failed
     print "Can't change to $1, aborting"
     return 1
     ;;
     esac
 }                    # END of pshd

 function popd
 {
     integer levels=${1:-1}

     if (( pushlevel-levels>=0 ))
       then
     let pushlevel=pushlevel-levels
       else
     print "Can't pop that many levels. Your choices were:"
     dirs
     print "You are being returned to your original level"
         let pushlevel=0
     fi

     ch ${dirsave[$pushlevel]}
     pwd            # show the user where they are.
     : ${2:+`ls -Fx $3 $4 $5 $6 $7 $8 $9 >/dev/tty`}
     PS1="${promptsave[$pushlevel]}"
 }

 function dirs
 {
     integer level=$pushlevel
     integer lowest=$level-${1:-$level}
     if [ lowest -lt 0 ]
     then
         lowest=0
     fi
     print "    $level: $PWD"
     while [ level -gt lowest ]
     do
     let level=level-1
     print "    $level: ${dirsave[$level]}"
     done
     unset level lowest
 }

 function pshpwd
 {
 print $PWD  "${@:-}" >~/.current-pwd
 }

 function poppwd
 {
 print $(<~/.current-pwd)
 }

 ---- start of pshd family documentation ----
 # In brief, this routine is called in the form of:
 #       . ~/ksh/psh-pop.ksh name arg1 arg2 arg3 ...
 # and has to do the following:
 #               - Unalias all five related alias names.
 #               - Declare all five function bodies using those names.
 #               - Run the function that invoked this file, using the provided
 #                 arguments.

 # The first time one of these aliases is used, it needs to be "loaded". From
 # then on, each one represents a loaded function, and runs smoothly. The
 # advantages are that your .env is about a hundred lines smaller, and these
 # functions are only defined when used.

 # The first three routines are used to maintain and examine a directory stack
 # of traversals through the file system. They are:
 #       pshd [directory] [ls-indicator] [ls-arg] [ls-arg] [ls-arg]
 #       popd [levels]    [ls-indicator] [ls-arg] [ls-arg] [ls-arg]
 #       dirs [levels]

 # These are different than other versions of pshd that have been posted to
 # the net. Both pshd and popd have an optional first argument that tells
 # which directory to go to, or how many levels to backtrack. If a second
 # argument is specified (any string will do) then an "ls -C" is done after
 # the action is completed. Any additional arguments are passed to ls. For
 # example, "pshd /usr/spool/uucp l -l -a -t" will change the directory to
 # /usr/spool/uucp and then do an "ls -C -l -a -t" to show full descriptions
 # of all files in that directory in the orer that they were last changed.
 # The "-C" argument is used to force our version of ls to columnate the
 # output (even if it is going into a pipeline).

 # The next two routines are used to share information about the current
 # directory # between two windows on a DMD/BLIT or just to save the value
 # for later. Only one value is currently supported. They are:
 #       pshpwd [additional text]
 #       poppwd
 # Poppwd is often used in constructs like "cp *.c `poppwd`"

 ----------------------------------- end ---------------------------
 --
 Ron Heiby mcdchg!heiby   Moderator: mod.newprod & mod.os.unix

 --
 Ron Heiby, [e-mail]    Moderator: comp.newprod
 "Wrong is wrong, even when it helps you." Popeye
 --

 CHANGING GEARS: Migrating from ms-dos to *nix
 --------------
    article from Rick Mobley (LRARK)

 FROM DOS TO UNIX
 By Ricky Mobley, LRARK

 For those that wish to enter the exciting world of UNIX, sometimes refered to
 as *NIX to cover XENIX and other derivatives, you will find that some of the
 commands are very similar. You may even wonder which came first, the chicken
 or the egg. UNIX dates back to the mid 60's, DOS can be thought of as a subset
 of UNIX since it became popular in the early 70's. Some commands that are
 similar would be 'type' which came from 'cat', short for concatanate, format
 which still exists, 'dir' which is replaced by 'ls' and many others.

 The amazing and sometimes the part which tends to scare off the weak at heart
 is the fact that "*NIX is a bottomless pit". That statement is true because of
 the large number of manuals that come with a system. Many times a command will
 also have the statement "see also" which will more than likely send you off to
 another book. Before you know it, you have 5 or 6 manuals open and may still
 not fully understand the command you are working with. Thats where the wizards
 come in. It is sometimes best to ask someone that has been using *NIX for a
  while to get a Reader's Digest version without going fully into the manuals.
 You must be careful with this approach as you might get the dreadful 'RTFM'
 reply on the simple ones. I'll leave that one for you to figure out.

 I have been running *NIX for a long time, and since I left DOS, I have yet to
 find one application that I couldn't mimic given the many many utilities that
 *NIX comes with. Last count was somewhere around 200. Hows that for a rich
 operating system?

 In order for you to appreciate the power of this O/S you will have to install
 it and use it for a while. There are several good manuals available to get you
 started, and of course, there is always the RT on Genie that is filled with
 knowledgable users of *NIX. Join in the fun and begin to tap the deep dark
 secrets of *NIX. I know you will enjoy it.

 Next time, I will go into more details of the O/S and what it has to offer the
 first time user.

 rick@lrark
 --


 MACAWK : Sub: awk, nawk, gawk, pcawk, macawk
 ------
    humorware from Mike Nolan (M.NOLAN)

 In the beginning, there was 'awk', written by the 3 authors whose initials
 make up the name.  And AT&T looked at awk, and decided it was of no
 consequence, which was good as it was distributed for free.

 And then it was said, "But awk needs improvement", and, yea, it came to
 pass that there was a new awk, or nawk.  And AT&T looked at nawk and
 decided it was good, which was bad because then it was bundled.

 And it came to pass in the halls of MIT that Richard Stallman said,
 "Let programmers go forth and multiply, and let the fruits of their
 labors be as free as the air, and let there be a new kernel, conceived
 in liberty and dedicated to the proposition that all modifications are
 charged for to support the FSF"  (oops, sorry, wrong text.)

 But it came to pass that there was a GNU day, and GNU software began
 to arise like weeds in the vineyard, with an insidious copyleft to
 make the source code a part of all distributions.  And thus was gawk,
 a GNU version of awk, as opposed to the new version of awk, was born.

 And the God of programmers looked down upon these awk-ward days, and
 declared that the three versions should be only partially compatible,
 in keeping with the fabled towers of Babylon.

 And then the God of programmers declared, go forth and multiply, which
 confused everyone, because forth had not yet been ported.  But there
 arose a multitudes of awk-like programs, such as pcawk and macawk,
 and to this day this awk-full multitude does continue to propogate,
 but usually without support.

 I hope this clarifies things.
 Michael Nolan
 --

 Op-Ed: Where Unix is going...
 --------------------------
   article from Dave Weinstein (OLORIN)

    A few years back, the Unix community was buzzing with rumors and
 speculation over the announcement that a number of companies which had
 formerly specialized in extremely proprietary systems had formed a
 consortium to create an "Open Unix". Against OSF was the Sun/AT&T
 alliance, and flames and rampant speculation about what all of this
 would mean for the future of Unix systems were the rage.

   Well, it's been a few years, and it's hard to remember why the furor
 rose. OSF has been mostly silent (although Motif has become a standard of
 sorts), and the spectre of a Sun/AT&T monopoly seems to have disappeared
 as SPARC based Unix clones arrived on the market from many of the same
 forces which flourished in the PC Clone market.

   And now a whole new slew of rumors and speculation have arisen over the
 falling out between Microsoft and IBM, the ACE Consortium, and the new
 and highly touted Apple/IBM/Motorola alliance.

   So why does the (primarily) PC infighting of the past month affect
 Unix? Far more companies have Unix capable PCs than have dedicated
 Unix machines of any stripe. And the decision to use Windows, X, the Mac,
 or any number of systems is no longer one of the scale of the problem,
 but which system provides the environment which will be productive
 quickly. It isn't the technical expertise which wins this war, but the
 marketing, and Unix is facing stronger threats now than in recent years.
 Early reports of OS/2 2.0 make it a true player in the office environment,
 and the cost of comparable Unix systems (as well as resource drain) is
 much higher. The Unix vendors can no longer afford to price full blown
 implementations at $500-$1200, the high end PCs and PC specific platforms
 are pushing hard into the Workstation market...
 --

 CUSTOMIZING the User Agent :
 --------------------------
  Brian Riley (DELPHI) continues his excellent 'hands-on' setup of a
  Unix system User Agent, using the venerable 3b1 as his model.

                   Customizing the User Agent (tm)
                         on the Unix Pc (tm)
                          by Brian T. Riley
                               Part 4


         Well, here we are again. If you remember last time, we
 were having fun with our .profile's. I promised to explain the
 rest of mine. Ok, Here we go! :)

 -----------------------------------------

 #sccs     "@(#)install:.profile    1.3"

 set -amh -o vi
 umask 000
 VISUAL=/usr/bin/vi
 PCOMM=$HOME/Pcomm
 ROGUEOPTS="name=Delphi"
 ENV=$HOME/.kshrc
 HISTFILE=$HOME/.ksh.hist
 HISTSIZE=24
 > $HISTFILE


 if [ "$L0" != "u" ]
 then
           exec /usr/bin/ua
 fi

 -----------------------------------------

         The first line should look familiar. It does this;


 -a      allexport       Exports all variables when set.

 -m      monitor         Displays process # for bg jobs.

 -h      trackall        Makes aliases tracked.

 -o vi   sets vi editing mode for command line.


         The rest is as follows;

 Umask sets the file creation mode mask. The value after the
 command is subtracted from the system default mode value. On the
 Unix-pc, without this command, the default mode is 0644. With the
 command I get 0755. VISUAL= makes vi the default editor no matter
 what the EDITOR= value. This way I can set the EDITOR= variable
 to another value for programs that ignore the VISUAL= variable
 and still have vi for the rest. PCOMM= tells Pcomm the
 communications program where my configuration files are and
 ROGUEOPTS= sets default options when I play the game. These are
 two examples of how programers can get information into their
 programs while giving the user flexibility.

 ENV= tells the Korn shell two things, first it says that we are
 using an environment file for the bulk of our aliases and
 functions and second it tells the shell where it is. By
 separating the aliases and functions from our .profile, and since
 it is a shell file, it is more readable and we can make changes
 without logging off. HISTFILE= and HISTSIZE= tell the shell where
 our history file is and how many of the previous commands we want
 to be able to recall. The next line is a little lesson in
 redirection. It has the effect of emptying my history file every
 time I log in.

 The last part we covered last time and lets me start without the
 User Agent if I put a "u" after my name when I log in. Did you
 notice the "$HOME" in some of my variable names? Ksh
 automatically expands this to the path of your home directory.
 This is available anywhere in the shell, even when you are
 changing your current directory. You could do this;

 cd $HOME/newdir

         Any of you who got them all right, give yourself a pat on
 the back but don't pull a muscle doing it! :) The Korn shell has
 some other interesting features as well. Say for example you are
 using your system at work and you are using a program that was
 written by your company for accounting. But today the program
 doesn't work, and you want to check it for problems but you don't
 know where it is! After all the system has hundreds of commands
 and programs. Well, you could ask everyone in the office where it
 is, (but you would look kind of stupid) or you could use
 "whence", like this;

 whence command <ret>

         which will tell you the full path to the program. You
 could also use the -v option to tell you what type of command or
 program it is. These are the possibilities;

 Reserved word
 Alias
 Exported alias
 Built-in shell command
 Undefined function
 Function
 Tracked alias
 Program
 Not found

         Well that's all I have for this installment but I would
         like you to post suggestions in the BBS for things you
         would like to know about and I will do what I can to
         answer your questions. Till next time...

 Happy trails to you....

      Brian T. Riley
      Delphi@UnixRt
      [e-mail]
 --

 ---------------
    REMINDER - This newsletter is being sent to you 'by request'. If you do
 not wish to keep receiving it, e-mail a stop notice to GARS. On the other
 hand, we would very much appreciate it if you would pass the word that we
 do distribute this item near the tenth (10th) of the month of issue to any-
 one on GEnie who requests it, and will gladly add any name that is requested
 via the same route... e-mail to GARS.
   P L E A S E  also remember contributions are most welcome. Please e-mail
 items and/or suggestions to GARS.

 (EOF)

  Trademark and Copyright notices:
  Unix is a Trademark of UNIX System Laboratories, Inc.; GEnie, LiveWire, and
  RoundTable are Trademarks of General Electric Information Services  Company;
  Xenix and ms-dos are Trademarks of Microsoft  Corporation;
 The contents of this newsletter are copyright (c) 1991 and may be copied whole
 or in part only if  original  credit is included. The GEnie UNIX RoundTable is
 not affiliated with AT&T or UNIX System Laboratories, Inc.