Path: utzoo!mnetor!uunet!husc6!cmcl2!nrl-cmf!ames!ucsd!sdcsvax!beowulf!holtz
From: holtz@beowulf.ucsd.edu (Fred Holtz)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Program Loaded Where? from inside another
Message-ID: <4872@sdcsvax.UCSD.EDU>
Date: 19 Apr 88 18:33:10 GMT
References: <39@softart.UUCP>
Sender: nobody@sdcsvax.UCSD.EDU
Organization: CSE Dept. U.C. San Diego
Lines: 36

In article <39@softart.UUCP> riml@softart.UUCP (Research in Motion Limited) writes:
>I have a program which invokes another program via an exec-type call
>("system()" in C).  In mess-dos so far, this means your calling program
>goes away until the new program has done its stuff.  My calling program
>needs to know where the called program got loaded in memory.  Does
>anyone have any hints on how to do this?  

An idea that may work for you is to reserve a special memory location in
the caller for the called program to patch its address into,  and then
passing the address of this area as a parameter to the called program, like:

Calling program:
  char *area, **temp, buf[64];
  temp = &area;
  sprintf(buf, "pgmname %lx", temp);
  system(buf);

Called program:
  char **area, *address;
  /* ...  set up the address */
  sscanf(av[1], "%lx", &area);
  *area = address;

Upon return from the called program the caller should now have its "area" set
to the called "address",  which I am not sure how to set,  but if your goal is
passing back a data structure or function address it is simple enough to do.
This will have to be done using a large memory and data model for both.
These code fragments may not work exactly as is (this is off the top of my
head),  but I think the general idea is workable.  My only question is why
do you want to do this in the first place?


Fred Holtz

ARPA:  holtz@sdcsvax.UCSD.EDU
UUCP:  sdcsvax!holtz