Write a C-program without main() method

[bagkalyan]

please help me..

Yes it is possible to write a program in c without using main.
Here is the code:

/* prog_without_main.c */
_start()
{
_exit(my_main());
}
int my_main(void)
{
printf(”Hello\n”);
return 42;
}

And use this command (% is command prompt) to compile:
%gcc -O3 -nostartfiles prog_without_ma in.c
Try compiling this example:

#include<stdio.h>
#define decode(s,t,u,m,p,e,d) m##s##u##t
#define begin decode(a,n,i,m,a,t,e)
void begin()
{
printf(”hello”);
}

here is how it works once we say define we need to understand that
#define x y
then ‘x’ ix replaced by ‘y’
similarly in this case
#define begin decode(a,n,i,m, a,t,e)
decode(a,n,i,m, a,t,e) is replaced by m##a##i##n
bcoz s is replaced by a,t by n,u by i and so on
s->a
t->n
u->i
m->m
p->a
e->t
d->e
now the statement becomes
void m##a##i##n
And u must be knowing that ## is used for string concatenation so it becomes
“main”
finally the code crops down to

void main()
{
printf(”hello”);
}

[Nepomuk]

please help me..

Yes it is possible to write a program in c without using main.
Here is the code:
...

This most certainly belongs in the C/C++ Forum! ^^

Greetings,
Nepomuk

[Purple]

Hi bagkalyan and welcome to TSDN,

As this post is a technical question related to c/c++, I have moved it from the cafe to the appropriate forum.

Take a moment to read the posting guidelines for this site here.

MODERATOR

[ilikepython]

please help me..

Yes it is possible to write a program in c without using main.
Here is the code:
/* prog_without_ma in.c */
_start()
{
_exit(my_main() );
}
int my_main(void)
{
printf(”Hello\n ”);
return 42;
}
And use this command (% is command prompt) to compile:
%gcc -O3 -nostartfiles prog_without_ma in.c
Try compiling this example:
#include<stdio. h>
#define decode(s,t,u,m, p,e,d) m##s##u##t
#define begin decode(a,n,i,m, a,t,e)
void begin()
{
printf(”hello”) ;
}
here is how it works once we say define we need to understand that
#define x y
then ‘x’ ix replaced by ‘y’
similarly in this case
#define begin decode(a,n,i,m, a,t,e)
decode(a,n,i,m, a,t,e) is replaced by m##a##i##n
bcoz s is replaced by a,t by n,u by i and so on
s->a
t->n
u->i
m->m
p->a
e->t
d->e
now the statement becomes
void m##a##i##n
And u must be knowing that ## is used for string concatenation so it becomes
“main”
finally the code crops down to
void main()
{
printf(”hello”) ;
}

The second really isn't a program without main. Like you said, it comes to the compiler like:

void main()
{
 

Anyway, what is your question?

[JosAH]

The second really isn't a program without main. Like you said, it comes to the compiler like:

void main()
{
 

Erm, it's "int", not "void". "int"; remember that: int, int, int, intintintintint intint!

kind regards,

Jos ;-)