c++.dos.32-bits - get machine name

peter <peter_member pathlink.com> Feb 01 2005

Heinz Saathoff <hsaat despammed.com> Feb 03 2005

Peter <Peter_member pathlink.com> Feb 07 2005

Peter <Peter_member pathlink.com> Feb 22 2005

peter <peter_member pathlink.com> writes:

Hi

I'm having problem with the following code compiled under DOSX. I've been stuck
on this for a couple of days but seem to get nowhere. 

Any help would be much appreciated.

I'm using the orginal Symantec compiler control version 7.2b2.
Library: sdx.lib 25/06/1998 10:53

I want to get the computer name of the workstation running my DOSX program so I
decided to use an interrupt call 0x5e00, however the machine name is never
returned. 

Code:


#include <dos.h>
#include <io.h>
#include <stdlib.h>
#include <stdio.h>

void main()
{

char  buffer[17] = "<buffer-------->";

union  REGS  regs_in, regs_out;

regs_in.e.eax = 0x5e00;
regs_in.e.ebx = 0;
regs_in.e.ecx = 0;
regs_in.e.edx = (unsigned)buffer;
regs_in.e.cflag = 0;

regs_out.e.eax = 0;
regs_out.e.ebx = 0;
regs_out.e.ecx = 0;
regs_out.e.edx = 0;
regs_out.e.cflag = 0;

printf("\n REGS IN ax:%x bx:%x cx:%x dx:%x cflag:%x",
regs_in.e.eax,
regs_in.e.ebx,
regs_in.e.ecx,
regs_in.e.edx,
regs_in.e.cflag
);
printf("\n REGS OUT ax:%x bx:%x cx:%x dx:%x cflag:%x",
regs_out.e.eax,
regs_out.e.ebx,
regs_out.e.ecx,
regs_out.e.edx,
regs_out.e.cflag
);


printf("\nbuffer = {%s}", buffer);

int86(0x21, &regs_in, &regs_out);

printf("\nbuffer = {%s}", buffer);

printf("\n REGS IN ax:%x bx:%x cx:%x dx:%x cflag:%x",
regs_in.e.eax,
regs_in.e.ebx,
regs_in.e.ecx,
regs_in.e.edx,
regs_in.e.cflag
);

printf("\n REGS OUT ax:%x bx:%x cx:%x dx:%x cflag:%x",
regs_out.e.eax,
regs_out.e.ebx,
regs_out.e.ecx,
regs_out.e.edx,
regs_out.e.cflag
);

}

Thanks for any help

Regards
Peter

Feb 01 2005

Heinz Saathoff <hsaat despammed.com> writes:

Hello Peter,

peter wrote...
 I'm having problem with the following code compiled under DOSX. I've been stuck
 on this for a couple of days but seem to get nowhere. 
 
 Any help would be much appreciated.
 
 I'm using the orginal Symantec compiler control version 7.2b2.
 Library: sdx.lib 25/06/1998 10:53
 
 I want to get the computer name of the workstation running my DOSX program so I
 decided to use an interrupt call 0x5e00, however the machine name is never
 returned. 
 
 [Code snipped]


The DOSX extender doesn't support several DOS calls directly. These can 
be called indirectly only. For additional information (such as this 
machine name) a buffer is needed that can be accessed in both real and 
protected mode. It's a bit tricky to do. 
I've rewritten the code to work here. It works when compiled with the 
actual DigitalMars Compiler and DOSX from http://www.dosextender.com 
I don't know if it also runs with the DOS extender that was supplied 
with Symantec 7.2. If not you may try to upgrade.

BTW, when loading the actual DOS-extender you will also find a manual 
with viewer where all the supported functions are documented.

Regards,
	Heinz

=================== CODE ==================
#include <dos.h>
#include <stdio.h>

#pragma pack(push,2)
struct RMI {   // struct to call real mode interrupts
   unsigned short irq_num;
   unsigned short ds;
   unsigned short es;
   unsigned short fs;
   unsigned short gs;
   unsigned long  eax;
   unsigned long  edx;
};
#pragma pack(pop)

struct XR_BUFFER {
   char __far *pp;     // x32 protected mode pointer;
   unsigned short segm;  // real mode segment
   unsigned short offs;  // real mode offset
};


struct XR_BUFFER GetBufferAdr()
{
   struct XR_BUFFER xr;

   asm {
      push  es
      mov   eax,0x250d     // Get Transfer Buffer Address
      int   0x21
      mov   xr.offs,bx
      shr   ebx,16
      mov   xr.segm,bx
      mov   bx,es          // seg
      mov   DWord Ptr xr.pp,edx
      mov   Word Ptr xr.pp+4,bx
      pop   es
   }
   return xr;
}


int main()
{
   struct XR_BUFFER x32_dos_buffer;
   struct RMI       rmi;
   char             local_buffer[64];
   int              i;

   x32_dos_buffer = GetBufferAdr();
   fprintf(stderr, "Real(%04x:%04x), Prot(%04x:%08x)\n",
        x32_dos_buffer.segm, x32_dos_buffer.offs,
        FP_SEG(x32_dos_buffer.pp), FP_OFF(x32_dos_buffer));

   rmi.irq_num = 0x21;     // DOS interrupt
   rmi.eax     = 0x5e00;   // get machine name
   rmi.edx     = x32_dos_buffer.offs;      /* real mode offset of 
transfer buffer */
   rmi.ds      = x32_dos_buffer.segm;      // real mode offset

   asm {
      mov   eax,0x2511
      lea   edx,rmi
      int   0x21
   }

   // now information is in transfer buffer
   // because the extender uses this buffer when doing I/O we copy
   // the contents to a local buffer first;
   for(i=0; i<64 && (local_buffer[i]=x32_dos_buffer.pp[i])!=0; ++i) ;
   printf("Name returned is %s\n", local_buffer);
   return 0;
}//main

================== end CODE ===============

Feb 03 2005

Peter <Peter_member pathlink.com> writes:

Hi Heinz,

Thanks for your post.

I tried your code on Symantec 7.2 compiler with its dos extender but did not
work.

I will do as you have suggested and will look at upgrading the dos extender
first to see if it will work with the Symantec compiler, if it still fails I
will use DM.

Kind regards

Peter

In article <MPG.1c6c40156eb8758d9896ee news.digitalmars.com>, Heinz Saathoff
says...
Hello Peter,

peter wrote...
 I'm having problem with the following code compiled under DOSX. I've been stuck
 on this for a couple of days but seem to get nowhere. 
 
 Any help would be much appreciated.
 
 I'm using the orginal Symantec compiler control version 7.2b2.
 Library: sdx.lib 25/06/1998 10:53
 
 I want to get the computer name of the workstation running my DOSX program so I
 decided to use an interrupt call 0x5e00, however the machine name is never
 returned. 
 
 [Code snipped]


The DOSX extender doesn't support several DOS calls directly. These can 
be called indirectly only. For additional information (such as this 
machine name) a buffer is needed that can be accessed in both real and 
protected mode. It's a bit tricky to do. 
I've rewritten the code to work here. It works when compiled with the 
actual DigitalMars Compiler and DOSX from http://www.dosextender.com 
I don't know if it also runs with the DOS extender that was supplied 
with Symantec 7.2. If not you may try to upgrade.

BTW, when loading the actual DOS-extender you will also find a manual 
with viewer where all the supported functions are documented.

Regards,
	Heinz

=================== CODE ==================
#include <dos.h>
#include <stdio.h>

#pragma pack(push,2)
struct RMI {   // struct to call real mode interrupts
   unsigned short irq_num;
   unsigned short ds;
   unsigned short es;
   unsigned short fs;
   unsigned short gs;
   unsigned long  eax;
   unsigned long  edx;
};
#pragma pack(pop)

struct XR_BUFFER {
   char __far *pp;     // x32 protected mode pointer;
   unsigned short segm;  // real mode segment
   unsigned short offs;  // real mode offset
};


struct XR_BUFFER GetBufferAdr()
{
   struct XR_BUFFER xr;

   asm {
      push  es
      mov   eax,0x250d     // Get Transfer Buffer Address
      int   0x21
      mov   xr.offs,bx
      shr   ebx,16
      mov   xr.segm,bx
      mov   bx,es          // seg
      mov   DWord Ptr xr.pp,edx
      mov   Word Ptr xr.pp+4,bx
      pop   es
   }
   return xr;
}


int main()
{
   struct XR_BUFFER x32_dos_buffer;
   struct RMI       rmi;
   char             local_buffer[64];
   int              i;

   x32_dos_buffer = GetBufferAdr();
   fprintf(stderr, "Real(%04x:%04x), Prot(%04x:%08x)\n",
        x32_dos_buffer.segm, x32_dos_buffer.offs,
        FP_SEG(x32_dos_buffer.pp), FP_OFF(x32_dos_buffer));

   rmi.irq_num = 0x21;     // DOS interrupt
   rmi.eax     = 0x5e00;   // get machine name
   rmi.edx     = x32_dos_buffer.offs;      /* real mode offset of 
transfer buffer */
   rmi.ds      = x32_dos_buffer.segm;      // real mode offset

   asm {
      mov   eax,0x2511
      lea   edx,rmi
      int   0x21
   }

   // now information is in transfer buffer
   // because the extender uses this buffer when doing I/O we copy
   // the contents to a local buffer first;
   for(i=0; i<64 && (local_buffer[i]=x32_dos_buffer.pp[i])!=0; ++i) ;
   printf("Name returned is %s\n", local_buffer);
   return 0;
}//main

================== end CODE ===============

Feb 07 2005

Peter <Peter_member pathlink.com> writes:

Hi Heinz,

Thanks for the snippet of code. Orignally I couldn't get this code to work on
the symantec compiler 7.2 with its built in dos extender.

The code GPF on line

   for(i=0; i<64 && (local_buffer[i]=x32_dos_buffer.pp[i])!=0; ++i) ;




For some reason it didn't like the pointer x32_dos_buffer.pp

Therefore I created a pointer from the real mode segment/offset, and this
worked, but I don't understand why it didn't like the protected mode ptr.

This worked.
char *ptr = (char *)
(-_x386_get_abs_address(MK_FP(getDS(), 0)) + 
(x32_dos_buffer.segm << 4) + x32_dos_buffer.offs);

for(i=0; i<64 && (local_buffer[i]=*ptr)!=0; ptr++, ++i) ;

I compiled the program using "sc -mx compname.cpp"

Anyway, thanks for your help Heinz.



In article <cu7nqg$1uhi$1 digitaldaemon.com>, Peter says...
Hi Heinz,

Thanks for your post.

I tried your code on Symantec 7.2 compiler with its dos extender but did not
work.

I will do as you have suggested and will look at upgrading the dos extender
first to see if it will work with the Symantec compiler, if it still fails I
will use DM.

Kind regards

Peter

In article <MPG.1c6c40156eb8758d9896ee news.digitalmars.com>, Heinz Saathoff
says...
Hello Peter,

peter wrote...
 I'm having problem with the following code compiled under DOSX. I've been stuck
 on this for a couple of days but seem to get nowhere. 
 
 Any help would be much appreciated.
 
 I'm using the orginal Symantec compiler control version 7.2b2.
 Library: sdx.lib 25/06/1998 10:53
 
 I want to get the computer name of the workstation running my DOSX program so I
 decided to use an interrupt call 0x5e00, however the machine name is never
 returned. 
 
 [Code snipped]


The DOSX extender doesn't support several DOS calls directly. These can 
be called indirectly only. For additional information (such as this 
machine name) a buffer is needed that can be accessed in both real and 
protected mode. It's a bit tricky to do. 
I've rewritten the code to work here. It works when compiled with the 
actual DigitalMars Compiler and DOSX from http://www.dosextender.com 
I don't know if it also runs with the DOS extender that was supplied 
with Symantec 7.2. If not you may try to upgrade.

BTW, when loading the actual DOS-extender you will also find a manual 
with viewer where all the supported functions are documented.

Regards,
	Heinz

=================== CODE ==================
#include <dos.h>
#include <stdio.h>

#pragma pack(push,2)
struct RMI {   // struct to call real mode interrupts
   unsigned short irq_num;
   unsigned short ds;
   unsigned short es;
   unsigned short fs;
   unsigned short gs;
   unsigned long  eax;
   unsigned long  edx;
};
#pragma pack(pop)

struct XR_BUFFER {
   char __far *pp;     // x32 protected mode pointer;
   unsigned short segm;  // real mode segment
   unsigned short offs;  // real mode offset
};


struct XR_BUFFER GetBufferAdr()
{
   struct XR_BUFFER xr;

   asm {
      push  es
      mov   eax,0x250d     // Get Transfer Buffer Address
      int   0x21
      mov   xr.offs,bx
      shr   ebx,16
      mov   xr.segm,bx
      mov   bx,es          // seg
      mov   DWord Ptr xr.pp,edx
      mov   Word Ptr xr.pp+4,bx
      pop   es
   }
   return xr;
}


int main()
{
   struct XR_BUFFER x32_dos_buffer;
   struct RMI       rmi;
   char             local_buffer[64];
   int              i;

   x32_dos_buffer = GetBufferAdr();
   fprintf(stderr, "Real(%04x:%04x), Prot(%04x:%08x)\n",
        x32_dos_buffer.segm, x32_dos_buffer.offs,
        FP_SEG(x32_dos_buffer.pp), FP_OFF(x32_dos_buffer));

   rmi.irq_num = 0x21;     // DOS interrupt
   rmi.eax     = 0x5e00;   // get machine name
   rmi.edx     = x32_dos_buffer.offs;      /* real mode offset of 
transfer buffer */
   rmi.ds      = x32_dos_buffer.segm;      // real mode offset

   asm {
      mov   eax,0x2511
      lea   edx,rmi
      int   0x21
   }

   // now information is in transfer buffer
   // because the extender uses this buffer when doing I/O we copy
   // the contents to a local buffer first;
   for(i=0; i<64 && (local_buffer[i]=x32_dos_buffer.pp[i])!=0; ++i) ;
   printf("Name returned is %s\n", local_buffer);
   return 0;
}//main

================== end CODE ===============

Feb 22 2005

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c++.dos.32-bits - get machine name