envtrim
      Program to reset PARENT-process MS DOS environment variables


USAGE
	envtrim -{l|r}nn var [ -{l|r}nn var ]*


FUNCTION

	envtrim trims from the left or right ("l" or "r") to a specified
 count of characters ("nn") the value associated with environment
variable  "var".   One or more environment variables can be truncated in
a single  invocation of envtrim.  The environment variables in the
PARENT process are  modified.

	For example, if the following environment variables are set
at the root COMMAND.COM level as
		USERNAME=jasmith
		STATION=0000c0251af3
then
		envtrim -l3 username -r6 station
results in
		USERNAME=jas
		STATION=251af3

	This capability is useful, for example, for truncating full Netware 
username strings to 3-character strings used by network-aware programs such 
as WordPerfect.  


METHOD

	envtrim copies the environment block from the parent into local
strings, modifies the strings, and copies the strings back to the
parent's environment.  

ERROR CONDITIONS

	envtrim reports an error if switch letter is not preceeded by a
'-', if the switch letter is not followed by a number, if an invalid
switch letter is  entered, or if the environment variable whose value
is  to be trimmed cannot be found in the working environment block.

LANGUAGE AND COMPATIBILITY

	envtrim is written in TURBOC for MS DOS computers.  It has been
tested on DOS 3.3 and DOS 4.01.  Since it does not use DOS calls to
effect the modifications (can't, since DOS provides no mechanism to
modify the parent's environment), envtrim may not be compatible with
future versions of DOS.

AUTHOR

	envtrim was written by H. D. Todd, Computing Center, Wesleyan
University, December, 1990, using prototypes written by Douglas Bigelow,
at the same address. envtrim is provided in source form and may be
distributed freely providing author information is retained.  The author
would appreciate receiving bug reports and copies of modifications and
improvements (HDTodd@eagle.wesleyan.edu or HDTodd@wesleyan.bitnet).