I'm probably just coding something wrong, but every time I try to _spawnl a
certain program, I get an 0Dh (Hard Disk) general protection fault, possible
illegal memory address. I use the _P_WAIT style (spawn and wait till
termination) rather than the overlay and terminate parent process. I'm assuming
that the program (developed third-party) is 16-bit, and doesn't run in protected
mode from a direct spawn, I'm not sure though.
How does one spawn a 16 bit real-mode program from a 32-bit protected mode
program?

The program in question is tiffcp.exe, a free tool for collating .tif images.

Try building a simple hello world program and see if that can be successfully spawned. -Walter

"E. Trelmar" <E._member@pathlink.com> wrote in message news:aghoa0$1j84$1@digitaldaemon.com...
> I'm probably just coding something wrong, but every time I try to _spawnl
a
> certain program, I get an 0Dh (Hard Disk) general protection fault,
possible
> illegal memory address. I use the _P_WAIT style (spawn and wait till termination) rather than the overlay and terminate parent process. I'm
assuming
> that the program (developed third-party) is 16-bit, and doesn't run in
protected
> mode from a direct spawn, I'm not sure though.
> How does one spawn a 16 bit real-mode program from a 32-bit protected mode
> program?
>
> The program in question is tiffcp.exe, a free tool for collating .tif
images.
>
>

In article <aghpm8$1kt7$2@digitaldaemon.com>, Walter says...
>
>Try building a simple hello world program and see if that can be successfully spawned. -Walter

I should have specified, it doesn't spawn any 16 bit programs. I just tried 32-bit programs though, going off a tangent on your suggestion, and those generate the same error. So I tried generating a 32-bit program with nothing but a _spawnl command. It won't spawn either 32-bit or 16-bit programs (Again, the same error). Is this simply my machine? Can anyone else get _spawnl to work in 32-bit dos?

"E. Trelmar" <E._member@pathlink.com> wrote in message news:aghqk5$1lht$1@digitaldaemon.com...
> I should have specified, it doesn't spawn any 16 bit programs. I just
tried
> 32-bit programs though, going off a tangent on your suggestion, and those generate the same error. So I tried generating a 32-bit program with
nothing but
> a _spawnl command. It won't spawn either 32-bit or 16-bit programs (Again,
the
> same error). Is this simply my machine? Can anyone else get _spawnl to
work in
> 32-bit dos?

I use this program all the time and it spawns successfully.
---------------------------------------------------------
/*_ timer.c   Mon Feb 29 1988   Modified by: Walter Bright */ /* Written by Walter Bright   */

#include <stdio.h>
#include <stdlib.h>
#if _WIN32
#include <windows.h>
typedef long long timer_t;
#else
#include <time.h>
#endif

#if __SC__ && !_WIN32
int _okbigbuf = 0; /* Use as little memory as possible */
#endif

int main(argc,argv)
int argc;
char *argv[];
{
 int status;
#if _WIN32
 timer_t starttime;
 timer_t freq;
 timer_t endtime;
 timer_t secs;
 timer_t fraction;

 if (argc < 2)
 { printf("Time execution of a command.\nUse:\n\ttimer command\n");
  exit(EXIT_FAILURE);
 }
 argv[argc] = 0;  /* terminate with a 0 (unportable method) */
 QueryPerformanceFrequency((LARGE_INTEGER *)&freq);
 QueryPerformanceCounter((LARGE_INTEGER *)&starttime);
 status = spawnvp(0,argv[1],argv + 1);
 QueryPerformanceCounter((LARGE_INTEGER *)&endtime);
 if (status == -1)
 { printf("'%s' failed to execute\n",argv[1]);
  exit(EXIT_FAILURE);
 }

 starttime = endtime - starttime;
 secs = starttime / freq;
 starttime -= secs * freq;
 fraction = (starttime * 10000) / freq;
 printf("Elapsed time = %lld.%04lld seconds\n",secs,fraction);
#else
 clock_t clock(),starttime;

 if (argc < 2)
 { printf("Time execution of a command.\nUse:\n\ttimer command\n");
  exit(1);
 }
 argv[argc] = 0;  /* terminate with a 0 (unportable method) */
 starttime = clock();
 status = spawnvp(0,argv[1],argv + 1);
 starttime = clock() - starttime;
 if (status == -1)
 { printf("'%s' failed to execute\n",argv[1]);
  exit(1);
 }
 printf("Elapsed time = %d.%02d seconds\n",(int) (starttime/CLK_TCK),
  (int) (starttime%CLK_TCK));
#endif
 if (status != 0)
  printf("--- errorlevel %d\n",status);
 return status;
}

#if __SC__ && !_WIN32

/* Prevent exit() and fclose() from being linked in from library */
/* (to conserve the size of the output file).    */

void exit(exitstatus)
int exitstatus;
{
 _exit(exitstatus);
}
#endif

Both your program Walter (With process.h #included so it compiles for me) and the example programs work successfully. Luckily, I just found out the problem was that I wasn't passing a final NULL pointer to the spawnl series. Thank you for the replies, I appreciate the help.