www.digitalmars.com         C & C++   DMDScript  

c++ - big file...

reply Anuj Goyal <Anuj_member pathlink.com> writes:
just curious as to why this file is so large...

D:\jam>cat a.c
#include <stdio.h>
#include <stdlib.h>
#include <windows.h>

int main()
{
int i = GetCurrentProcessId();
printf("i = %d\n",i);
return 0;
}


D:\jam>dmc -WA -6 -o+all a.c
link a,,,user32+kernel32/noi;


D:\jam>ls -al a.exe
-rwxrwxrwx   1 user     group       39964 Apr 30 23:02 a.exe

is there an easy way to "strip" an executable?
Apr 30 2005
parent reply "Matthew" <admin stlsoft.dot.dot.dot.dot.org> writes:
There's nothing to strip. Your call to printf() guarantees you 
linkage to the C runtime library, and that's around 40K IIRC.

You could try
    WriteFile(GetStdHandle(STD_HANDLE_OUTPUT), "Hello", 5, . . .

(may have the syntax wrong)

If you want low footprint integer to string conversions, use 
STLSoft's integer_to_string, as in:

    /* STLSoft Header Files */
    #include <stlsoft.h>
    #include <stlsoft_integer_to_string.h>

    /* Standard C Header Files */
    #include <windows.h>

    /* Standard C++ Header Files */

    /* 
////////////////////////////////////////////////////////////////////////// 
*/

    int main(int /* argc */, char ** /*argv*/)
    {
        DWORD    pid =   ::GetCurrentProcessId();
        char             sz[21];
        size_t           n;
        char const   *s  =   ::stlsoft::integer_to_string(sz, 21, 
(__int32)pid, n);
        DWORD    dummy;

        ::WriteFile(::GetStdHandle(STD_OUTPUT_HANDLE), s, n, &dummy, 
NULL);

        return 0;
    }

    /* 
////////////////////////////////////////////////////////////////////////// 
*/


That compiles and builds to 2048 bytes with VC++ 7.1.

(You need the __int32 because of a bug - soon to be fixed! - in the 
STLSoft libs.)


"Anuj Goyal" <Anuj_member pathlink.com> wrote in message 
news:d51rkp$20sp$1 digitaldaemon.com...

 just curious as to why this file is so large...

 D:\jam>cat a.c
 #include <stdio.h>
 #include <stdlib.h>
 #include <windows.h>

 int main()
 {
 int i = GetCurrentProcessId();
 printf("i = %d\n",i);
 return 0;
 }


 D:\jam>dmc -WA -6 -o+all a.c
 link a,,,user32+kernel32/noi;


 D:\jam>ls -al a.exe
 -rwxrwxrwx   1 user     group       39964 Apr 30 23:02 a.exe

 is there an easy way to "strip" an executable?
May 01 2005
next sibling parent Sammy <Sammy.Deroy sympatico.ca> writes:
Matthew wrote:

 There's nothing to strip. Your call to printf() guarantees you 
 linkage to the C runtime library, and that's around 40K IIRC.
 
 That compiles and builds to 2048 bytes with VC++ 7.1.



Interesting.

What is the exact command line you have used ?

Are you using VC++ Professional Version (with optimisations) ?

I have the 2003 Standard Version which does not permit optimisations.
May 01 2005
prev sibling parent reply "Walter" <newshound digitalmars.com> writes:
"Matthew" <admin stlsoft.dot.dot.dot.dot.org> wrote in message
news:d51vdf$23uo$2 digitaldaemon.com...

 That compiles and builds to 2048 bytes with VC++ 7.1.



Probably because you're linking to the VC runtime DLL.
May 01 2005
parent reply "Matthew" <admin stlsoft.dot.dot.dot.dot.org> writes:
Puh-lease! Give me some credit.

See attached DepencyViewer, and if you don't believe that, run the 
exe. ;-)



"Walter" <newshound digitalmars.com> wrote in message 
news:d548u4$p3u$1 digitaldaemon.com...

 "Matthew" <admin stlsoft.dot.dot.dot.dot.org> wrote in message
 news:d51vdf$23uo$2 digitaldaemon.com...

 That compiles and builds to 2048 bytes with VC++ 7.1.



 Probably because you're linking to the VC runtime DLL.
May 01 2005
parent reply "Matthew" <admin stlsoft.dot.dot.dot.dot.org> writes:
Oops sorry for the huge bmp. I should've made it smaller. :$

btw, I'm sure I could have got smaller than 2048, as I'm aware that 
there are various packing / packaging options for doing so. (not off 
the top of my head, of course.)

"Matthew" <admin stlsoft.dot.dot.dot.dot.org> wrote in message 
news:d54a7t$qr0$1 digitaldaemon.com...

 Puh-lease! Give me some credit.

 See attached DepencyViewer, and if you don't believe that, run the 
 exe. ;-)



 "Walter" <newshound digitalmars.com> wrote in message 
 news:d548u4$p3u$1 digitaldaemon.com...

 "Matthew" <admin stlsoft.dot.dot.dot.dot.org> wrote in message
 news:d51vdf$23uo$2 digitaldaemon.com...

 That compiles and builds to 2048 bytes with VC++ 7.1.



 Probably because you're linking to the VC runtime DLL.
May 01 2005
parent reply Sammy <Sammy.Deroy sympatico.ca> writes:
Matthew wrote:

 
 btw, I'm sure I could have got smaller than 2048, as I'm aware that 
 there are various packing / packaging options for doing so. (not off 
 the top of my head, of course.)
 



Hi Matthew,

You choose to ignore my post :-)
Of course that's ok.

It did probably upset you.
Because the question in it was two fold:

1) i really wanted to know how you did it.
    But as you ignored my post, i decided to do
    some research by myself.

2) I think the merit for the small size exe
    must be credited the the fact that the linker
    do 50% of the job and the other 50% comes
    from the fact that the called functions are
    available in kernel32.dll. And i was asking you
    to illustrate that to me.

So in order to come clean with you, i do offer
my apology, now, without conditions.

If i dont come clean with you, i am, at least
clean with BOB.


 That compiles and builds to 2048 bytes with VC++ 7.1.












I have done some test with VC++ 6.0, and the best i got
was 800 bytes with the following program:

#include <windows.h>
#ifdef __DMC__
int _acrtused_con;
#endif

int main( )
{
   static char buf[21];
   wsprintf(buf,"pid: %d",(int)GetCurrentProcessId());
   WriteFile( GetStdHandle(STD_OUTPUT_HANDLE),
     buf, lstrlen(buf), NULL, NULL );
   return 0;
}

but now, we must use two dll: user32 and kernel32.

The good news, the same result, can almost be be achieved
with DMC.

The following command:
   dmc -NL -o+all  10.c /L/entry:_main
do produce a 3200 bytes exe.

Strangely, this exe *can* compressed, by UPX,
to the smallest size i got: 2048 bytes, and
still being a valid executable.

Ok, case closed (well, i guess).

Cheers.

Sammy
May 02 2005
next sibling parent "Walter" <newshound digitalmars.com> writes:
"Sammy" <Sammy.Deroy sympatico.ca> wrote in message
news:d55fv9$1tp0$1 digitaldaemon.com...

 #include <windows.h>
 #ifdef __DMC__
 int _acrtused_con;
 #endif

 int main( )
 {
    static char buf[21];
    wsprintf(buf,"pid: %d",(int)GetCurrentProcessId());
    WriteFile( GetStdHandle(STD_OUTPUT_HANDLE),
      buf, lstrlen(buf), NULL, NULL );
    return 0;
 }

 but now, we must use two dll: user32 and kernel32.

 The good news, the same result, can almost be be achieved
 with DMC.

 The following command:
    dmc -NL -o+all  10.c /L/entry:_main
 do produce a 3200 bytes exe.



I never thought of doing that! Pretty cool, and my congratulations.
May 02 2005
prev sibling next sibling parent reply Jan Knepper <jan smartsoft.us> writes:
Sammy wrote:

 Matthew wrote:
 

 btw, I'm sure I could have got smaller than 2048, as I'm aware that 
 there are various packing / packaging options for doing so. (not off 
 the top of my head, of course.)



 Hi Matthew,
 
 You choose to ignore my post :-)
 Of course that's ok.
 
 It did probably upset you.
 Because the question in it was two fold:
 
 1) i really wanted to know how you did it.
    But as you ignored my post, i decided to do
    some research by myself.
 
 2) I think the merit for the small size exe
    must be credited the the fact that the linker
    do 50% of the job and the other 50% comes
    from the fact that the called functions are
    available in kernel32.dll. And i was asking you
    to illustrate that to me.
 
 So in order to come clean with you, i do offer
 my apology, now, without conditions.
 
 If i dont come clean with you, i am, at least
 clean with BOB.
 
  >>>> That compiles and builds to 2048 bytes with VC++ 7.1.
 
 I have done some test with VC++ 6.0, and the best i got
 was 800 bytes with the following program:
 
 #include <windows.h>
 #ifdef __DMC__
 int _acrtused_con;
 #endif
 
 int main( )
 {
   static char buf[21];
   wsprintf(buf,"pid: %d",(int)GetCurrentProcessId());
   WriteFile( GetStdHandle(STD_OUTPUT_HANDLE),
     buf, lstrlen(buf), NULL, NULL );
   return 0;
 }



Try:
    #include <stdlib.h>

    char   buf [ 24 ];
    ltoa ( GetCurrentProcessId (), buf, 10 );
    WriteFile ( GetStdHandle ( STD_OUTPUT_HANDLE ), buf, lstrlen ( buf 
), 0, 0 );


 
 but now, we must use two dll: user32 and kernel32.
 
 The good news, the same result, can almost be be achieved
 with DMC.
 
 The following command:
   dmc -NL -o+all  10.c /L/entry:_main
 do produce a 3200 bytes exe.
 
 Strangely, this exe *can* compressed, by UPX,
 to the smallest size i got: 2048 bytes, and
 still being a valid executable.
 
 Ok, case closed (well, i guess).
 
 Cheers.
 
 Sammy
 
 
 
 
     




-- 
ManiaC++
Jan Knepper

But as for me and my household, we shall use Mozilla...
www.mozilla.org
May 02 2005
parent Sammy <Sammy.Deroy sympatico.ca> writes:
Jan Knepper wrote:

 
 Try:
    #include <stdlib.h>
 
    char   buf [ 24 ];
    ltoa ( GetCurrentProcessId (), buf, 10 );
    WriteFile ( GetStdHandle ( STD_OUTPUT_HANDLE ), buf, lstrlen ( buf ), 
 0, 0 );
 



You suggest to use ltoa( ) instead of wsprintf( ).
That gives an ever smaller exe (2588 bytes, see below).

You still needs windows.h. Looks like stdlib.h did not
pull in the DMC runtime.

/* 11.c */
#include <windows.h>
#include <stdlib.h>
int _acrtused_con=0;
int main( )
{
    char buf[ 24 ];
    ltoa(GetCurrentProcessId( ),buf,10);
    _lwrite((int)GetStdHandle(-11L),buf,lstrlen(buf));
    return 0;
}

Compiled with:
   dmc -NL -o+all 11.c /L/entry:_main snn.lib
gives:

2005-05-02  18:43 PM             2,588 11.exe

This exe depends only on kernel32.dll and ntdll.dll.

Undocumented ntdll.dll contains a lot of functions ( like ltoa ).
if we could have an import library for it, DMC could be
use to build tiny executables.

There is a 'tinylibc' librairie on the net which is
used to produce tiny exe.

It could probably work with DMC.
May 02 2005
prev sibling parent "Matthew" <admin stlsoft.dot.dot.dot.dot.org> writes:
 You choose to ignore my post :-)
 Of course that's ok.



No, I guess I just missed it.


 It did probably upset you.



Not so. What an odd thing to say. Why would you think that?


 Because the question in it was two fold:

 1) i really wanted to know how you did it.
    But as you ignored my post, i decided to do
    some research by myself.



Just specifying main as the entry point, and -nodefaultlib


 2) I think the merit for the small size exe
    must be credited the the fact that the linker
    do 50% of the job and the other 50% comes
    from the fact that the called functions are
    available in kernel32.dll. And i was asking you
    to illustrate that to me.

 So in order to come clean with you, i do offer
 my apology, now, without conditions.



Now you're freaking me out! :-)

Nothing to apologise for. No problem whatsoever at this end.


 If i dont come clean with you, i am, at least
 clean with BOB.


 That compiles and builds to 2048 bytes with VC++ 7.1.












 I have done some test with VC++ 6.0, and the best i got
 was 800 bytes with the following program:

 #include <windows.h>
 #ifdef __DMC__
 int _acrtused_con;
 #endif

 int main( )
 {
   static char buf[21];
   wsprintf(buf,"pid: %d",(int)GetCurrentProcessId());
   WriteFile( GetStdHandle(STD_OUTPUT_HANDLE),
     buf, lstrlen(buf), NULL, NULL );
   return 0;
 }

 but now, we must use two dll: user32 and kernel32.



800 bytes sounds about right.


 The good news, the same result, can almost be be achieved
 with DMC.

 The following command:
   dmc -NL -o+all  10.c /L/entry:_main
 do produce a 3200 bytes exe.



Interesting. I've never tried this with DMC. Nice one. :)
May 02 2005