segmentation fault in recursion

[asit]

#include <stdio.h>

int main()
{
int i;
for(i=1;i<=10;i ++)
main();
printf("C is urs..");
return 0;
}

Why it shows error segmentation fault ??

[vippstar]

On Jan 15, 10:09 pm, asit <lipu...@gmail. comwrote:

#include <stdio.h>

int main()
{
int i;
for(i=1;i<=10;i ++)
main();
printf("C is urs..");
return 0;

}

Why it shows error segmentation fault ??

Because you're a troll.
As far as C is concerned, that is perfectly valid code.
perhaps a system limitation. C (or c.l.c) has nothing to do with that.

[Eric Sosman]

vi******@gmail. com wrote:

On Jan 15, 10:09 pm, asit <lipu...@gmail. comwrote:

>#include <stdio.h>

int main()
{
int i;
for(i=1;i<=10;i ++)
main();
printf("C is urs..");
return 0;

}

Why it shows error segmentation fault ??

Because you're a troll.

You may be right about that.

As far as C is concerned, that is perfectly valid code.
perhaps a system limitation. C (or c.l.c) has nothing to do with that.

The code is "valid" in that it expresses a computation.
Unfortunately, the computation will not complete in finite
time, nor will a finite machine have an easy time keeping
track of its intermediate states. The inconvenient word
"finite" does in fact express a system limitation, but it's
a limitation that can be removed only with great difficulty
and at some expense.

--
Er*********@sun .com

[Keith Thompson]

vi******@gmail. com writes:

On Jan 15, 10:09 pm, asit <lipu...@gmail. comwrote:

>#include <stdio.h>

int main()
{
int i;
for(i=1;i<=10;i ++)
main();
printf("C is urs..");
return 0;

}

Why it shows error segmentation fault ??

Because you're a troll.
As far as C is concerned, that is perfectly valid code.
perhaps a system limitation. C (or c.l.c) has nothing to do with that.

The OP may or may not be a troll, but I wouldn't call the code
"perfectly valid". It's an infinite recursive loop, and the program
will attempt to consume infinite resources unless the compiler manages
to optimize away the recursion. main() calls itself 10 times. Each
of these 10 instances will again call main 10 times. And so on.

--
Keith Thompson (The_Other_Keit h) <ks***@mib.or g>
Nokia
"We must do something. This is something. Therefore, we must do this."
-- Antony Jay and Jonathan Lynn, "Yes Minister"

[CBFalconer]

asit wrote:

>
#include <stdio.h>

int main() {
int i;
for(i=1;i<=10;i ++)
main();
printf("C is urs..");
return 0;
}

Why it shows error segmentation fault ??

PLONK.

--
[mail]: Chuck F (cbfalconer at maineline dot net)
[page]: <http://cbfalconer.home .att.net>
Try the download section.

--
Posted via a free Usenet account from http://www.teranews.com

[Mark Bluemel]

Eric Sosman wrote:

vi******@gmail. com wrote:

>On Jan 15, 10:09 pm, asit <lipu...@gmail. comwrote:

>>#include <stdio.h>

int main()
{
int i;
for(i=1;i<=10;i ++)
main();
printf("C is urs..");
return 0;

}

Why it shows error segmentation fault ??

Because you're a troll.

You may be right about that.

I'm not convinced that he's a troll, but I decided that whether he was a
troll or simply an unteachable idiot, he was worth adding to my
killfile.

[Eric Sosman]

Keith Thompson wrote:

vi******@gmail. com writes:

>On Jan 15, 10:09 pm, asit <lipu...@gmail. comwrote:

>>#include <stdio.h>

int main()
{
int i;
for(i=1;i<=10;i ++)
main();
printf("C is urs..");
return 0;

}

Why it shows error segmentation fault ??

Because you're a troll.
As far as C is concerned, that is perfectly valid code.
perhaps a system limitation. C (or c.l.c) has nothing to do with that.

The OP may or may not be a troll, but I wouldn't call the code
"perfectly valid". It's an infinite recursive loop, and the program
will attempt to consume infinite resources unless the compiler manages
to optimize away the recursion. main() calls itself 10 times. Each
of these 10 instances will again call main 10 times. And so on.

It would be proper to say that main() calls itself once
or calls itself Aleph-nought times (depending on the point of
view), but I don't think "10 times" can be defended.

--
Er*********@sun .com

[Keith Thompson]

Eric Sosman <Er*********@su n.comwrites:

Keith Thompson wrote:

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

>>On Jan 15, 10:09 pm, asit <lipu...@gmail. comwrote:
#include <stdio.h>

int main()
{
int i;
for(i=1;i<=10;i ++)
main();
printf("C is urs..");
return 0;

}

Why it shows error segmentation fault ??
Because you're a troll.
As far as C is concerned, that is perfectly valid code.
perhaps a system limitation. C (or c.l.c) has nothing to do with that.

The OP may or may not be a troll, but I wouldn't call the code
"perfectly valid". It's an infinite recursive loop, and the program
will attempt to consume infinite resources unless the compiler manages
to optimize away the recursion. main() calls itself 10 times. Each
of these 10 instances will again call main 10 times. And so on.

It would be proper to say that main() calls itself once
or calls itself Aleph-nought times (depending on the point of
view), but I don't think "10 times" can be defended.

Ok, main *in its initial invocation* attempts to call itself 10 times.
It fails to do so, because the first call will never return.

(Strictly speaking, main does call itself 10 times. It then calls
itself again and again and again until resources are exhausted. But
the value 10 is not related to the 10 in the for loop, so my statement
was correct only by coincidence.)

--
Keith Thompson (The_Other_Keit h) <ks***@mib.or g>
Nokia
"We must do something. This is something. Therefore, we must do this."
-- Antony Jay and Jonathan Lynn, "Yes Minister"

[CBFalconer]

Keith Thompson wrote:

Eric Sosman <Er*********@su n.comwrites:

>Keith Thompson wrote:

>>vi******@gmail. com writes:
asit <lipu...@gmail. comwrote:

#include <stdio.h>
>
int main() {
int i;
for(i=1;i<=10;i ++)
main();
printf("C is urs..");
return 0;
}
>
Why it shows error segmentation fault ??

Because you're a troll. As far as C is concerned, that is
perfectly valid code. perhaps a system limitation. C (or c.l.c)
has nothing to do with that.

The OP may or may not be a troll, but I wouldn't call the code
"perfectly valid". It's an infinite recursive loop, and the
program will attempt to consume infinite resources unless the
compiler manages to optimize away the recursion. main() calls
itself 10 times. Each of these 10 instances will again call
main 10 times. And so on.

It would be proper to say that main() calls itself once
or calls itself Aleph-nought times (depending on the point of
view), but I don't think "10 times" can be defended.

Ok, main *in its initial invocation* attempts to call itself 10
times. It fails to do so, because the first call will never return.

(Strictly speaking, main does call itself 10 times. It then calls
itself again and again and again until resources are exhausted.
But the value 10 is not related to the 10 in the for loop, so my
statement was correct only by coincidence.)

However a smart enough compiler could optimize it to:

#include <stdio.h>
int main(void) {
while (1) printf("C is urs..");
return 0;
}

(ignoring the failure to output any '\n's). The result should
progress considerably faster.

--
[mail]: Chuck F (cbfalconer at maineline dot net)
[page]: <http://cbfalconer.home .att.net>
Try the download section.

--
Posted via a free Usenet account from http://www.teranews.com

[Keith Thompson]

CBFalconer <cb********@yah oo.comwrites:
[...]

>>>>asit <lipu...@gmail. comwrote:
>
>#include <stdio.h>
>>
>int main() {
> int i;
> for(i=1;i<=10;i ++)
> main();
> printf("C is urs..");
> return 0;
>}

[...]

However a smart enough compiler could optimize it to:

#include <stdio.h>
int main(void) {
while (1) printf("C is urs..");
return 0;
}

(ignoring the failure to output any '\n's). The result should
progress considerably faster.

No, that would be an invalid optimization. In the original program,
even assuming infinite resources, the printf call will never be
reached.

It could be optimized to:

int main(void) {
while (1);
}

The only difference in behavior would be the lack of memory exhaustion
(a "stack overflow" in some implementations ).

--
Keith Thompson (The_Other_Keit h) <ks***@mib.or g>
Nokia
"We must do something. This is something. Therefore, we must do this."
-- Antony Jay and Jonathan Lynn, "Yes Minister"