can u explain this code?

[kartheeknagasuri]

my friend gave this code to me..... it is working fine....how come?

please explain me if u can understand.....

#include <stdio.h>
#include <conio.h>
#define _(__,___)\
___##__
_(id,vo) _8(_(
ar,ch)a,_(ar ,ch
)*_2){_(ile,wh) (a
--)_(ntf, pri)("%s"
,_2);}_(id,vo) _1(_
(nt,i) s,_(nt,i) n,
_(nt,i) k=1,_(ar,ch
) *_3="* "){_8 ( k,
"\n");_8(s, " ");_8(
n,_3);}_(id,vo) _6(_(nt,i) k,_(nt,i)
l,_(ar,ch) *_9_){_8(k,"\n" );_8(l, " ");_(ile
,wh)(*_9_)_(ntf ,pri)("%c",*_9_ ++-12);} _(id,
vo) _(in,ma)(){_(ar ,ch) _1_1_[]="cu€" "t,nq"
"€,~qsm~p8",_2 _2_[]="X{wm";_(ar,ch ) _22[]=
{240,32,0},_4;_ 1(20,3,6);_1(19 ,1)
;_1(4,1,0);_1(1 9,1); _1(1,1, 0,
_22);_1(1,1,0); _1(19,1);
_1(4,1,0);_1(15 ,8);
_1(13,10);_1(0, 1,0,"*");_
(or,f)(_4=0;_4< 4;_4++) {_1(15+_4*2,
8-_4*2);_(f,i)(_4 ==0) _1(0,2,0," *");}_(
or,f)(_4=2;_4>= 0;_4--)_1(15+_4*2,8-_4*2);_6(3,
26,_1_1_);_6(2, 40,_2_2_);_(ile ,wh)(!_(it,kbh) ());}

[Richard Heathfield]

ka************* *@gmail.com said:

my friend gave this code to me..... it is working fine....how come?

foo.c:2: conio.h: No such file or directory

Looks like it doesn't work fine after all.

And even if you ignore that, it gets the entry point's return type wrong, so
the behaviour of the program is undefined. There's nothing even remotely
fine about this program.

--
Richard Heathfield
"Usenet is a strange place" - dmr 29/7/1999
http://www.cpax.org.uk
email: rjh at above domain (but drop the www, obviously)

[Tak-Shing Chan]

On Tue, 8 Aug 2006 ka************* *@gmail.com wrote:

my friend gave this code to me..... it is working fine....how come?

please explain me if u can understand.....

#include <stdio.h>
#include <conio.h>
#define _(__,___)\
___##__
_(id,vo) _8(_(
ar,ch)a,_(ar ,ch
)*_2){_(ile,wh) (a
--)_(ntf, pri)("%s"
,_2);}_(id,vo) _1(_
(nt,i) s,_(nt,i) n,
_(nt,i) k=1,_(ar,ch
) *_3="* "){_8 ( k,
"\n");_8(s, " ");_8(
n,_3);}_(id,vo) _6(_(nt,i) k,_(nt,i)
l,_(ar,ch) *_9_){_8(k,"\n" );_8(l, " ");_(ile
,wh)(*_9_)_(ntf ,pri)("%c",*_9_ ++-12);} _(id,
vo) _(in,ma)(){_(ar ,ch) _1_1_[]="cu€" "t,nq"
"€,~qsm~p8",_2 _2_[]="X{wm";_(ar,ch ) _22[]=
{240,32,0},_4;_ 1(20,3,6);_1(19 ,1)
;_1(4,1,0);_1(1 9,1); _1(1,1, 0,
_22);_1(1,1,0); _1(19,1);
_1(4,1,0);_1(15 ,8);
_1(13,10);_1(0, 1,0,"*");_
(or,f)(_4=0;_4< 4;_4++) {_1(15+_4*2,
8-_4*2);_(f,i)(_4 ==0) _1(0,2,0," *");}_(
or,f)(_4=2;_4>= 0;_4--)_1(15+_4*2,8-_4*2);_6(3,
26,_1_1_);_6(2, 40,_2_2_);_(ile ,wh)(!_(it,kbh) ());}

Nonportabilitie s [1] aside, the actual obfuscation here is
fairly simple: #define _(__,___) ___##__ concatenates its two
arguments in reverse. Thus, _(id,vo) gives gives you void,
_(ar,ch)*_2 gives you char*_2 (and so forth).

Tak-Shing

[1] I would leave it to the pedants to enumerate them.

[Morris Dovey]

Tak-Shing Chan (in
Pi************* *************** **...o.gold .ac.uk) said:

| On Tue, 8 Aug 2006 ka************* *@gmail.com wrote:
|
|| my friend gave this code to me..... it is working fine....how come?
||
|| please explain me if u can understand.....
||
|| #include <stdio.h>
|| #include <conio.h>
||
||
|| #define _(__,___)\
|| ___##__
|| _(id,vo) _8(_(
|| ar,ch)a,_(ar ,ch
|| )*_2){_(ile,wh) (a
|| --)_(ntf, pri)("%s"
|| ,_2);}_(id,vo) _1(_
|| (nt,i) s,_(nt,i) n,
|| _(nt,i) k=1,_(ar,ch
|| ) *_3="* "){_8 ( k,
|| "\n");_8(s, " ");_8(
|| n,_3);}_(id,vo) _6(_(nt,i) k,_(nt,i)
|| l,_(ar,ch) *_9_){_8(k,"\n" );_8(l, " ");_(ile
|| ,wh)(*_9_)_(ntf ,pri)("%c",*_9_ ++-12);} _(id,
|| vo) _(in,ma)(){_(ar ,ch) _1_1_[]="cu?" "t,nq"
|| "?,~qsm~p8",_2 _2_[]="X{wm";_(ar,ch ) _22[]=
|| {240,32,0},_4;_ 1(20,3,6);_1(19 ,1)
|| ;_1(4,1,0);_1(1 9,1); _1(1,1, 0,
|| _22);_1(1,1,0); _1(19,1);
|| _1(4,1,0);_1(15 ,8);
|| _1(13,10);_1(0, 1,0,"*");_
|| (or,f)(_4=0;_4< 4;_4++) {_1(15+_4*2,
|| 8-_4*2);_(f,i)(_4 ==0) _1(0,2,0," *");}_(
|| or,f)(_4=2;_4>= 0;_4--)_1(15+_4*2,8-_4*2);_6(3,
|| 26,_1_1_);_6(2, 40,_2_2_);_(ile ,wh)(!_(it,kbh) ());}
|
| Nonportabilitie s [1] aside, the actual obfuscation here is
| fairly simple: #define _(__,___) ___##__ concatenates its two
| arguments in reverse. Thus, _(id,vo) gives gives you void,
| _(ar,ch)*_2 gives you char*_2 (and so forth).
|
| Tak-Shing
|
| [1] I would leave it to the pedants to enumerate them.

Ugh, not pretty! With liberal renaming I got:

#include <stdio.h>
#include <conio.h>

void fna(char a,char *s)
{ while (a--) printf("%s",s);
}

void fnb(int k,int l,char *9)
{ fna(k,"\n");
fna(l, " ");
while(*9) printf("%c",*9+ +-12);
}

void fnc(int s,int n,int k=1,char *t="* ")
{ fna(k,"\n");
fna(s," ");
fna(n,t);
}

void main()
{ char v1[] = "cu?t,nq?,~qsm ~p8",
v2[] = "X{wm",
v3[] = { 240,32,0 },
i;

fnc(20,3,6);
fnc(19,1);
fnc(4,1,0);
fnc(19,1);
fnc(1,1, 0,v3);
fnc(1,1,0);
fnc(19,1);
fnc(4,1,0);
fnc(15,8);
fnc(13,10);
fnc(0,1,0,"*");
for (i=0; i<4; i++)
{ fnc(15+i*2,8-i*2);
if (i==0) fnc(0,2,0," *");
}
for (i=2; i>=0; i--) fnc(15+i*2,8-i*2);
fnb(3,26,v1);
fnb(2,40,v2);
while (!kbhit()) ;
}

Left as an exercise for the OP to enumerate the problems.

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto

[Keith Thompson]

ka************* *@gmail.com writes:

my friend gave this code to me..... it is working fine....how come?

please explain me if u can understand.....

"u" doesn't read this newsgroup. If you meant "you", please say so.
Silly abbreviations like "u" for "you" are discouraged here.

#include <stdio.h>
#include <conio.h>

This is a system-specific header.

>
#define _(__,___)\
___##__

The identifiers __ and ___ are reserved to the implementation.

Leaving that aside, the macro takes two arguments and pastes them
together in reverse order. For example, "_(id,vo)" expands to "void".

_(id,vo) _8(_(
ar,ch)a,_(ar ,ch
)*_2){_(ile,wh) (a

[snip]

It's not worth my time to wade through all that noise. If you're
curious find out if your compiler has an option to show you the output
of the preprocessor. Coment out the #include directives so it doesn't
insert the contents of those headers into the output.

--
Keith Thompson (The_Other_Keit h) ks***@mib.org <http://www.ghoti.net/~kst>
San Diego Supercomputer Center <* <http://users.sdsc.edu/~kst>
We must do something. This is something. Therefore, we must do this.

[Harald van Dijk]

Keith Thompson wrote:

ka************* *@gmail.com writes:

>#define _(__,___)\
___##__

The identifiers __ and ___ are reserved to the implementation.

Even as macro arguments? On comp.std.c I was told that

#if 0
__special
#endif
int main(void) {}

and

#ifdef __special
/* nothing */
#endif
int main(void) {}

are both strictly conforming -- essentially because __special is only
reserved for "any" use after preprocessing. During preprocessing, it is
reserved for use as a macro name, but not for anything beyond that unless
it doesn't affect any (otherwise) strictly conforming program. Since naming
your macro arguments __ and ___ prevents any predefined macros __ and ___
from being expanded, I think that should be fine.

[Keith Thompson]

Harald van Dijk <tr*****@gmail. comwrites:

Keith Thompson wrote:

>ka************* *@gmail.com writes:

>>#define _(__,___)\
___##__

The identifiers __ and ___ are reserved to the implementation.

Even as macro arguments? On comp.std.c I was told that

#if 0
__special
#endif
int main(void) {}

and

#ifdef __special
/* nothing */
#endif
int main(void) {}

are both strictly conforming -- essentially because __special is only
reserved for "any" use after preprocessing. During preprocessing, it is
reserved for use as a macro name, but not for anything beyond that unless
it doesn't affect any (otherwise) strictly conforming program. Since naming
your macro arguments __ and ___ prevents any predefined macros __ and ___
from being expanded, I think that should be fine.

You may be right; I'm not sure. (I avoid the issue by avoiding
identifiers starting with '_' altogether.)

--
Keith Thompson (The_Other_Keit h) ks***@mib.org <http://www.ghoti.net/~kst>
San Diego Supercomputer Center <* <http://users.sdsc.edu/~kst>
We must do something. This is something. Therefore, we must do this.

[Michael Mair]

Harald van Dijk schrieb:

Keith Thompson wrote:

>>ka*********** ***@gmail.com writes:

>>>#define _(__,___)\
___##__

The identifiers __ and ___ are reserved to the implementation.

Even as macro arguments? On comp.std.c I was told that

#if 0
__special
#endif
int main(void) {}

and

#ifdef __special
/* nothing */
#endif
int main(void) {}

are both strictly conforming -- essentially because __special is only
reserved for "any" use after preprocessing. During preprocessing, it is
reserved for use as a macro name, but not for anything beyond that unless
it doesn't affect any (otherwise) strictly conforming program. Since naming
your macro arguments __ and ___ prevents any predefined macros __ and ___
from being expanded, I think that should be fine.

Predefined macro names must not be the subject of a #define or
#undef directive; i.e. #define __(_,___) ___##_ would not have
been allowed as _ followed by an uppercase letter or _ belongs to
the "implementa tion namespace" for predefined macro names. (C99,
6.10.8#4)
Identifiers starting with _ followed by an uppercase letter or
_ are always reserved for any use, identifiers starting with
_ followed by a lowercase letter are reserved for file scope
(ordinary and tag namespace) identifiers. (C99, 7.10.3#1)
As macro names are identifiers (C99, 6.2.1#1), I'd say you are
right.
Cheers
Michael
--
E-Mail: Mine is an /at/ gmx /dot/ de address.

[MQ]

ka************* *@gmail.com wrote:

my friend gave this code to me..... it is working fine....how come?

please explain me if u can understand.....

#include <stdio.h>
#include <conio.h>
#define _(__,___)\
___##__
_(id,vo) _8(_(
ar,ch)a,_(ar ,ch
)*_2){_(ile,wh) (a
--)_(ntf, pri)("%s"
,_2);}_(id,vo) _1(_
(nt,i) s,_(nt,i) n,
_(nt,i) k=1,_(ar,ch
) *_3="* "){_8 ( k,
"\n");_8(s, " ");_8(
n,_3);}_(id,vo) _6(_(nt,i) k,_(nt,i)
l,_(ar,ch) *_9_){_8(k,"\n" );_8(l, " ");_(ile
,wh)(*_9_)_(ntf ,pri)("%c",*_9_ ++-12);} _(id,
vo) _(in,ma)(){_(ar ,ch) _1_1_[]="cu€" "t,nq"
"€,~qsm~p8",_2 _2_[]="X{wm";_(ar,ch ) _22[]=
{240,32,0},_4;_ 1(20,3,6);_1(19 ,1)
;_1(4,1,0);_1(1 9,1); _1(1,1, 0,
_22);_1(1,1,0); _1(19,1);
_1(4,1,0);_1(15 ,8);
_1(13,10);_1(0, 1,0,"*");_
(or,f)(_4=0;_4< 4;_4++) {_1(15+_4*2,
8-_4*2);_(f,i)(_4 ==0) _1(0,2,0," *");}_(
or,f)(_4=2;_4>= 0;_4--)_1(15+_4*2,8-_4*2);_6(3,
26,_1_1_);_6(2, 40,_2_2_);_(ile ,wh)(!_(it,kbh) ());}

Yikes, someone has too much spare time....

[zhao.kaiyong]

ka************* *@gmail.com wrote:

my friend gave this code to me..... it is working fine....how come?

please explain me if u can understand.....

#include <stdio.h>
#include <conio.h>
#define _(__,___)\
___##__
_(id,vo) _8(_(
ar,ch)a,_(ar ,ch
)*_2){_(ile,wh) (a
--)_(ntf, pri)("%s"
,_2);}_(id,vo) _1(_
(nt,i) s,_(nt,i) n,
_(nt,i) k=1,_(ar,ch
) *_3="* "){_8 ( k,
"\n");_8(s, " ");_8(
n,_3);}_(id,vo) _6(_(nt,i) k,_(nt,i)
l,_(ar,ch) *_9_){_8(k,"\n" );_8(l, " ");_(ile
,wh)(*_9_)_(ntf ,pri)("%c",*_9_ ++-12);} _(id,
vo) _(in,ma)(){_(ar ,ch) _1_1_[]="cu€" "t,nq"
"€,~qsm~p8",_2 _2_[]="X{wm";_(ar,ch ) _22[]=
{240,32,0},_4;_ 1(20,3,6);_1(19 ,1)
;_1(4,1,0);_1(1 9,1); _1(1,1, 0,
_22);_1(1,1,0); _1(19,1);
_1(4,1,0);_1(15 ,8);
_1(13,10);_1(0, 1,0,"*");_
(or,f)(_4=0;_4< 4;_4++) {_1(15+_4*2,
8-_4*2);_(f,i)(_4 ==0) _1(0,2,0," *");}_(
or,f)(_4=2;_4>= 0;_4--)_1(15+_4*2,8-_4*2);_6(3,
26,_1_1_);_6(2, 40,_2_2_);_(ile ,wh)(!_(it,kbh) ());}

If u have many spare time. u can find all the code on IOCCC. This
place u can find what u want, hah