Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!wuarchive!cec2!news
From: jcb2647@cec1.wustl.edu (James Christopher Beard)
Newsgroups: comp.sys.ibm.pc
Subject: Re: How can I set a PATH longer than 128 bytes ?
Summary: Suggests an M.O. wherein long paths are not needed. . .
Keywords: path environment
Message-ID: <1990Mar8.021622.13121@cec1.wustl.edu>
Date: 8 Mar 90 02:16:22 GMT
References: <5762@ncrcae.Columbia.NCR.COM> <17140003@hplred.HP.COM>
Sender: news@cec2 (USENET News System)
Reply-To: jcb2647@cec1.wustl.edu (James Christopher Beard)
Organization: Washington University, St. Louis MO
Lines: 68

Sorry I can't help with the original problem, but I would like to
suggest that you set things up so that an extremely long path is not
needed.  How about using batch files (as noted by Bob Piety) to add
special-purpose directories to the path only when they are needed,
then remove them automatically?  There are some directories that
really should be on the path all the time, and others that are useless
except when you are running a particular application.  By way of
example, my AUTOEXEC.BAT includes the following:

PATH=C:\BAT;C:\UTIL;C:\DOS
SET REGPATH=%PATH%

(Note that this will not work with DOS 3.0, which mishandles the
variable substitution that makes "%PATH%" be understood as
"C:\BAT;C:\UTIL;C:\DOS" in the above example.  It works fine with 3.1
and later.)  MS Word, for example, is invoked with a batch file
(located in C:\BAT) that includes the lines

	PATH=C:\WORD;%PATH%
	. . .set up other stuff. . .
	WORD %1 %2 %3
	. . .
	PATH=%REGPATH%

The last command restores the path to the "general purpose" version
that was stored in the environment variable REGPATH by AUTOEXEC.BAT.

Why not have an enormous path that includes the home directory of
every application on the hard disk, the way the documentation and/or
installation program for so many applications recommend?  

For one thing, it is a substantial waste of time.  Every time you
invoke a program not in the current directory, the computer may search
through a whole bunch of directories that contain only special-purpose
programs.  If you're running QuickC, and C:\DEVEL\QC2 is the 10th
directory in the path, you unnecessarily search through 9 directories
every time you invoke one of QC's executables with the default
directory set to something other than C:\DEVEL\QC2.  And every time
you mistype a command name, practically the whole dang disc is
searched before you see "Bad command or file name".

For another thing, it wastes environment space and may exceed a hard
limit on the path length (but you already know about that).

(On the subject of environment space, you may well be aware already
that you can have as much space as you like by putting an
appropriate SHELL command in CONFIG.SYS:

	SHELL=C:\DOS\COMMAND.COM /P /E:nnn 

If you're using DOS 3.2 or later, nnn is the number of bytes to set
aside for the environment.  For DOS 3.1, nnn is the number of
16-byte "paragraphs" to set aside for the environment.)

If your path is of horrible length for some reason other than trying
to keep every known executable available at once, you can shorten the
number of characters in the path by giving some of the directories
"aliases" using the SUBST command a la 

	SUBST E: C:\PROGRAMS\JOE\WORDPROC\WP

Then you can include the virtual drive E: in your path.  Two notes,
though: 1) SUBST mustn't be used in a networked environment, which
seems like the place you're most likely to need it, and 2) for the
above to work, you need a command of the form "LASTDRIVE=E" in
CONFIG.SYS, where you replace "E" with the name of the
highest-lettered drive or virtual drive you will ever want to refer
to.