🚀 go-pugleaf

In article <1992Aug24.143641.1@camins.camosun.bc.ca>, morley@camins.camosun.bc.ca writes:
> In article <690@aardvark.Rain.COM>, tyrant@Aardvark.Rain.COM (Rex Goode) writes:
>> dmh@superb (Daniel Hermans) writes:
>> 
>>>hi,
>>>i am using turbo c v2.0 to generate a temporary file name,
>>>place some data in the temporary file and then close the file. the temp
>>>file is then to be used on the command line of another program. both
>>>programs are called within a batch file something like:
>> 
>>>@echo off
>> 
>>>program1
>>>program2 < %tempfile%
>> 
>>>   system("set tempfile=tmpx.$$$");
>> 
>>>i tried using system(command) as above but the variable is not set when the
>>>program exits probably because system starts a new command.com shell each
>>>time
>> 
>> Absolutely right about the new command.com, with its own environment. That
>> is what happens when you use system(). Try setenv(),
>> 
>> setenv("TEMPFILE=TMPX.$$$);
>> 
> 
> Sorry, but setenv() also only modifies the "local" environment.  It will not
> change it "permanently".
> 
> MARK
> morley@camins.camosun.bc.ca
> 

The best way I have found to set a global environment variable is to use 
interrupt 2e, the back door to the command interpreter. Construct a string 
with a command like "set x=y\r" and pass it to INT 2E via DS:DX. 

Since 2E destroys all regs except CS:IP, you must restore the SS:SP from
a place addressable from CS, and restore DS from the stack. 

If you have set a global environment variable and wish to access it
subsequently using getenv(), free the program's local environment and
point the environment segment in the PSP at its parent's environment.
If you do this, set the environment segment in the PSP to zero before
exiting, or program cleanup will attempt to delete the master environment.

Gery Dueck
dueck@brandonu.ca