ProfitPress Mega CDROM2 …eeware (MSDOS)(1992)(Eng)/ProfitPress-MegaCDROM2.B6I/UTILITY/SYSTEM/APATH23.ZIP/APATH.DOC

Text File | 1992-04-02 | 16.7 KB | 361 lines

APATH           Copyright (c) 1992    Walt Stoneburner
v2.3            All Rights Reserved.

Altering the current PATH environment variable can be a pain at times,
especially when the changes are minor.  APATH was designed to allow the PATH
variable to be manipulated quickly and easily without the overhead of extra
environment variables or terribly complex batch files.

APATH is ideal for modifying the path in everyday batch files, some makefiles,
LAN administration login/logout files, from the command line, etc.

The ability to remove directories from the PATH environment variable
until needed should result in quicker searches of the path.  Software that
requires its directory be in the path can be activated by a simple batch file
which makes a path addition, runs the software, and later removes the excess
baggage.

Entering APATH without arguments provides brief usage information. It also
shows off the copyright message.


Usage:
        APATH [/M] [+|-]path[;path...]

                /M              Changes affect the master environment.
                                No parameter changes the parent environment.

                path            Multiple directories may be specified,
                                separated by semicolons.  If a directory
                                is not already part of the PATH, it will be
                                prepended (placed in front).  If it is part of
                                the PATH, the path addition will be ignored.

                +path           Same as above, but the specified directory
                                will be appended to the end of the PATH.

                -path           The specified directory will be removed from
                                the PATH variable.  If the directory can not
                                be found, the deletion will be ignored.

        Multiple prepends, appends, and deletes may be specified on a
        single line.  Only the first character of each directory sequence
        may be a - or +.


APATH can return status information via the DOS errorlevel.

An errorlevel of 1 is returned if the path could not be changed successfully
(note that this errorlevel is not returned if you try to add an
already-existing element to the path, or delete one which didn't exist to
begin with; it's only returned if something awful happens).  APATH returns an
errorlevel of 0 if the command completes without incident.

Examples:
        APATH C:\UTIL                   Prepend C:\UTIL to front of PATH.

        APATH +C:\UTIL                  Append C:\UTIL to end of PATH.

        APATH -C:\UTIL                  Remove C:\UTIL from PATH.


        APATH /M C:\UTIL;C:\TMP         Prepend C:\UTIL then C:\TMP to PATH
                                        in master environment only.

        APATH +C:\UTIL;C:\BIN -D:\TMP F:\USR\LIB
                                        Append C:\UTIL then C:\BIN,
                                        Delete D:\TMP, and
                                        Prepend F:\USR\LIB to PATH.

Note:   The prepend function will effectively reverse the order of the
        specified directories.   e.g.  APATH A;B;C  will make  PATH=C;B;A
        This is because A is prepended, then B is prepended in front
        of the A, and finally C is prepended in front of B.

        Using the + to append will produce arguments in the same order
        as they are specified on the command line.


Other Examples Involving APATH:

    Starting Windows, in a WIN.BAT file:
      apath c:\aldus;c:\excel;c:\winword;c:\windows
      if errorlevel 1 goto opps
      win %1 %2 %3 %4 %5
      apath -c:\aldus;c:\excel;c:\winword;c:\windows
      goto quit
      :oops
      Echo could not adjust path!
      :quit

    Kill the whole path to impress the girls; anyone can type  PATH =
      apath -%path%

    Kill redundant entries in the path (works for short paths):
      apath -%path% +%path%

    Reverse the order of the path (just because!):
      apath -%path% %path%

    LAN login:
      net use f: \\moocow\c-drive
      apath f:\util

    LAN logout:
      net logout \\buckaroo
      apath -g:\sound

    In a "makefile":
      y_tab.c : grammar.y
        apath d:\usr\bin
        yacc grammer.y
        apath -d:\usr\bin



A Word About Makefiles

  Some MAKE programs store a copy of the PATH at runtime, thus with each line
  executed in a shell uses a copy of the path when invoked. If APATH doesn't
  seem to work, try using the /M parameter to change the master environment.
  If this still doesn't work, try using a MAKE which isn't brain-damaged.


Warning to Power Users

  I'm sure some wiseass will try to break the software by trying something
  like this:
    APATH %path% %path% %path% %path% %path% ...

  Good news for wiseasses everywhere!  Most likely you'll get the weird result
  you're looking for because COMMAND.COM doesn't have enough room to pass the
  whole command line to the program.

  My tests have shown that only 128 bytes get passed to APATH from the
  command line.  And one of those is the space after the command and the
  other is the return key.  So, really you have only 126 bytes in an
  argument.  Internal DOS commands do not seem to have this restriction.
  Anything after the 126th character magically disappears, so you could
  get part of a directory name appended!

  If you get into problems where APATH is acting funny for large arguments,
  break up your command into multiple APATH commands.  While I've provided
  for a 4K path in the program (in case anyone modifies their shell), DOS is
  limited to 128 bytes and 4DOS appears to have a larger 256 byte maximum for
  the size of an environment variable.

  The idea is that after using APATH (with some batch files) you'll have
  a much shorter path.  80 characters or less is quite reasonable and will
  offer in return a better response time if you happen to enter a bad
  command making DOS go searching your disk for something that isn't there.


A Word About Shells

  Some shells with evaluate %path% on the command line, such as 4DOS and
  its mutant sister, NDOS.  Others will only evaluate %path% while in a
  batch file.

  The only problem I've ever had with APATH is specifying multiple, large
  arguments using the above command line expansion in conjunction with
  MS-DOS as the underlying operating system.  The path used to get corrupted
  by extra garbage characters being inserted as a path.  I traced the problem
  to how MS-DOS puts parameters in the _PSP segment; under the right
  conditions a non-terminated string can result, screwing up
  most parsing routines.  The problem has a workaround in APATH v2.3.

  Note that DR-DOS doesn't have this PSP problem, so prior versions
  of APATH will work fine under this operating system.

  However, you don't have to toss MS-DOS to use older versions of APATH
  (like you really would); just keep the total length of the command-line
  arguments to 127 bytes or less per command line and applications will work
  fine, not just APATH.

  [ I suspect everyone knows that 4DOS is owned by Rex Conn and JP Software,
    that NDOS (a subset of 4DOS and the addition of the Norton Utilites) is
    owned by Symantic Corp, that MS-DOS is owned by Microsoft, that DR-DOS
    is owned by Digital Research, and that APATH is owned by Walt Stoneburner.

    Don't you think these 'ownership' paragraphs are a bore?  Look guys, if
    people don't know who you are, you need to spend a little more of that
    green stuff in marketing!  Get a life.  Enough said. ]



Version History

  v1.0  APATH developed; did extensive testing and multiple revisions
        before first public release.  Appends, Deletes [-], and Prepends [+]
        directories to the PATH environment variable.  Modifies the parent
        environment.  APATH was written completely in assembly language in an
        effort to keep size down and speed up.

  v2.0  Reversed meaning of + to mean append and made default prepend.
        [Code size increased to 2546 bytes long.]

  v2.1  Reduced code size 800 bytes [code size now 1746 bytes long].

  v2.2  Added /M for master environment.  Reduced source code 15 bytes
        [now 1731 bytes long].  Bug fix for empty environment.

  v2.3  Reduced code size by 41 more bytes [now 1690 bytes long; 8 from a
        restructure of the code, and 47 from hand optimizations, and
        added 14 for new features]!  Increased buffer size; that should allow
        for some hefty command lines.  This should also prevent bug reports
        from people complaining about really-really long paths if anyone
        writes a shell or operating system supporting them.  Added error
        levels.  Found MS-DOS _PSP bug and built workaround for it.


Thank You List

  Many thanks to Doug "Power User" Austin who beta-tested the software,
  gave me better insight on making the user interface better, corrected
  some documentation errors, and laughed at the jokes in the documentation
  without a lot of prodding.  He has the talent for finding the non-trivial-
  obvious mistakes during development.  He also handled a lot of the
  distribution of earlier versions... and got a whole minute of upload credit
  for this small file.

  Thanks to Tamara "So What's It Do?" Harrison for calling each night to
  make sure I wasn't sitting on my duff.  ...usually I was.  She offered
  a lot of support even when the nature of the utility wasn't clear or
  completely defined yet.  Is that something or what?

  Thanks to Phillip "Now What You Need..." Wherry, who inspired me that
  people ought to be able to put things at the end of the path.  He also
  made a few minor revisions to the documentation.



Disclaimer & Other Legal Stuff

  NO LIABILITY FOR CONSEQUENTIAL DAMAGES
  In no event whatsoever shall the author, suppliers of APATH, or basically
  anyone in the universe, be held liable for any damages whatsoever
  (including, without limitation to, damages for loss of business profits,
  business interruption, loss of business information, other pecuniary
  loss, paper cuts, or the destruction of the galaxy) arising out of the use,
  abuse, misuse, or inability to use this program, even if the author has
  been advised of the possibility of such damages.  If you are uncomfortable
  with the above, please do not use the program or send any money.  Look,
  this program was written for personal use; it worked well for me, so I'm
  virtually giving it away; I don't want my tush sued off because I was
  just being generous.  (This bag is not a toy!)

  NO WARRANTY EXPRESSED OR IMPLIED
  While you are free to try out the software for 30 days, do not send any
  money until you are satisfied with the program.  Monies cannot be
  returned.  No warranty or guarantee is provided that the software will
  operate as stated in this manual.

  GRANT OF LICENSE
  After sending the registration card below, you are free to use APATH
  on as many personal machines as you can possibly get your hands on from
  now until the Return of Christ.  Businesses are site licensed for a finite
  number of copies executing simultaneously on different machines (see
  registration card).

  COPYRIGHT
  This software is owned by Walt Stoneburner.  You are free to
  modify and patch this version to suit your needs.  However, please do not
  redistribute the patched version; you may redistribute the patch and/or
  instructions for making the patch.  I would prefer that people obtain clean
  copies in the event we choose to offer technical support.

  TECHNICAL SUPPORT
  We make no claims or promises for offering technical support.  However,
  if you write me, I'll consider it.  If you bribe me, I'll take you
  very seriously.

  OTHER RESTRICTIONS
  Don't hurt anyone.  It isn't nice.  Look both ways before crossing the
  street.  Kids, don't smoke or do drugs.  And if you're gonna drink and
  drive, get your parents' permission first.

  CUSTOMER REMEDIES
  Take an aspirin.  Read the directions.  Read them again.  Aside from that, I
  can't help you.



EMail Addresses

  If you'd like to write and try to weasel support, technical information,
  or source code from the author, he can -indirectly- be reached by the
  following EMail addresses.

  Please state clearly that your message pertains to APATH (give the
  version number).  These friendly people below will get the message to me
  one way or another and are not necessarily responsible for answering
  your pleas.  They are certainly not responsible if anything goes wrong.

    CompuServe:   70651,2707  or  72137,1152
    Internet:     [e-mail]  or  [e-mail]
    GEnie:        AUSI-DGATE  or  A.GARIES


Registration

  If you are an individual and are using APATH for personal use, you're in luck...
  Using APATH will cost you nothing, however, I would like you to send the
  registration form below in anyhow.  By not charging a fee to individuals,
  I'm hopeful you'll feel more inclined to let me know you are using
  something I've written, and that I should therefore devote more free time to
  projects like this.

  If you are a company, well... you're not as lucky as the individuals above.
  However I know that you will most likely want a site license or something
  like that.  And I'm willing to do that... cheap.  Very cheap!  (See below.)

  So... on with the paper work.

                Please fill out below and send to:

                        APATH Registration
                        c/o Walt Stoneburner
                        9307 Lundy Court
                        Burke, Virginia  22015


+----------------------------------------------------------------------------+
|                                                                            |
| APATH v2.3     Copyright (c) Walt Stoneburner                 Mar 31, 1992 |
| Registration   All Rights Reserved.                                        |
|                                                                            |
| Name:  ________________________________    [ ]  My personal use,           |
|                                                 no charge.  Thanks!        |
| Company:  _____________________________                                    |
|                                            [ ]  My personal use; I've      |
| Address:  _____________________________         enclosed $5 or more, send  |
|                                                 commented source code      |
|           _____________________________                                    |
|                                            [ ]  Company site license       |
|           _____________________________          1 - 19 users : $1.00/copy |
|                                                 20 - 49 users : $0.75/copy |
| Phone:    _____________________________         50 - infinity : $0.50/copy |
| Optional  [ Circle:  DAY  NIGHT  WORK ]                (up to $100)        |
|                                                                            |
| [ ]  Or...  we would like to distribute APATH with our products.  Enclosed |
|      is $100 which gives us an infinite site license for this product and  |
|      your permission to distribute this and future upgrades of APATH as    |
|      they become publicly accessible.                                      |
|                                                                            |
| ( )  I am interested in other        ( )  I would be interested in Beta    |
|      things you develop[ed] when          testing software as it is being  |
|      they become available.               developed.                       |
|                                                                            |
| EMail Address:  ________________________________________________________   |
|                                                                            |
| Comments / How Are You Using APATH:                                        |
|                                                                            |
| ________________________________________________________________________   |
|                                                                            |
| ________________________________________________________________________   |
|                                                                            |
| ________________________________________________________________________   |
|                                                                            |
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