how to call a variable without reference in c

[anto frank]

hi friends,

is it possible to call a variable from the main function to a sub
fuction with out sending as a argument, pointer and can't declare as
global variable?

void main()
{
int a=10;
fun();
}
fun( )
{
printf("%d", a);
}

condition
1. don't use pointer concept
2.don't declare as global variable
3.don't send as arguments

IS IT POSSIBLE?

please help me

[user923005]

On Sep 24, 11:19 pm, anto frank <[e-mail]:

hi friends,

is it possible to call a variable from the main function to a sub
fuction with out sending as a argument, pointer and can't declare as
global variable?

void main()

The main() function returns int.

{
int a=10;
fun();
}
fun( )
{
printf("%d", a);

}

condition
1. don't use pointer concept

It's going to be pretty hard to print without any pointers.

2.don't declare as global variable
3.don't send as arguments

IS IT POSSIBLE?

All things are possible except those that aren't.

For instance, write a file in function 1.
Read the file from function 2.

[Keith Thompson]

anto frank <j.************@gmail.comwrites:
[...]

condition
1. don't use pointer concept
2.don't declare as global variable
3.don't send as arguments

4. Do your own homework.

--
Keith Thompson (The_Other_Keith) 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."
-- Antony Jay and Jonathan Lynn, "Yes Minister"

[Richard Bos]

Keith Thompson <ks***@mib.orgwrote:

anto frank <j.************@gmail.comwrites:
[...]

condition
1. don't use pointer concept
2.don't declare as global variable
3.don't send as arguments

4. Do your own homework.

5. And while you're at it, kick your teacher. It's a stupid question.

Richard

[karthikbalaguru]

On Sep 25, 11:19 am, anto frank <[e-mail]:

hi friends,

is it possible to call a variable from the main function to a sub
fuction with out sending as a argument, pointer and can't declare as
global variable?

void main()
{
int a=10;
fun();
}
fun( )
{
printf("%d", a);

}

condition
1. don't use pointer concept
2.don't declare as global variable
3.don't send as arguments

IS IT POSSIBLE?

please help me

It is Funny, But Some ways are there :):):)
1)Write a into an external memory in main before calling fun and read
from the external memory in fun before printing it.
2)Do a bit of assembly and push it in memory stack explicitly and pop
it out explicitly using assembly in the fun.
3)Copy to free register of the CPU and read it out from there.

Karthik Balaguru

[Ivan Gotovchits]

anto frank wrote:

hi friends,

is it possible to call a variable from the main function to a sub
fuction with out sending as a argument, pointer and can't declare as
global variable?

void main()
{
int a=10;
fun();
}
fun( )
{
printf("%d", a);
}

condition
1. don't use pointer concept
2.don't declare as global variable
3.don't send as arguments

IS IT POSSIBLE?

please help me

I think that the idea is to access it through stack. Variable a lives in
stack in a range of 4 bytes, because there is a Return Address. (It may be
wrong, I'm not sure).
So you can try to address it in this way:

int
main(void)
{
int a = 10;
func();
}

int
func(void)
{
int *p;
p -= 2; /* a return address and p itself (8 bytes total) */
printf("%d\n", *p);
}

I am not sure that it will work, but you can try it. And if it fails, then
google for `buffer overflow'.
--
s/.../.gotovchits/g for email.

[Keith Thompson]

Ivan Gotovchits <iv*************@auriga.ruwrites:

anto frank wrote:

> is it possible to call a variable from the main function to a sub
fuction with out sending as a argument, pointer and can't declare as
global variable?

void main()
{
int a=10;
fun();
}
fun( )
{
printf("%d", a);
}

condition
1. don't use pointer concept
2.don't declare as global variable
3.don't send as arguments

I think that the idea is to access it through stack. Variable a lives in
stack in a range of 4 bytes, because there is a Return Address. (It may be
wrong, I'm not sure).
So you can try to address it in this way:

int
main(void)
{
int a = 10;
func();
}

int
func(void)
{
int *p;
p -= 2; /* a return address and p itself (8 bytes total) */
printf("%d\n", *p);
}

I am not sure that it will work, but you can try it. And if it fails, then
google for `buffer overflow'.

I'm afraid your proposed solution is nonsense. The variable 'p' is
uninitialized. Its initial value is garbage; even examining it
invokes undefined behavior. You assume that ints and pointers are the
same size, something that is not guaranteed by the language (and it's
untrue on several systems I use every day). Even if that were valid,
you make several unsupportable assumptions about stack layout (there
might not even be a stack in the usual sense).

Did you try it yourself? Why not?

--
Keith Thompson (The_Other_Keith) 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."
-- Antony Jay and Jonathan Lynn, "Yes Minister"

[Mark McIntyre]

On Tue, 25 Sep 2007 06:19:27 -0000, in comp.lang.c , anto frank
<j.************@gmail.comwrote:

>hi friends,

is it possible to call a variable from the main function to a sub

....

>condition
1. don't use pointer concept
2.don't declare as global variable
3.don't send as arguments

"Is it possible to eat sausages ?
Condition:
1. don't kill pig
2. don't construct sausage
3. don't send to mouth"

:-)

To answer your question - yes, sure. Just write the data to a file,
then read it in again. Ah, no - this needs a file pointer. Oh well.

If this is homework, your teacher needs upgrading....
--
Mark McIntyre

"Debugging is twice as hard as writing the code in the first place.
Therefore, if you write the code as cleverly as possible, you are,
by definition, not smart enough to debug it."
--Brian Kernighan