Pipeline implementation in C
 

I'm a student in uni, currently taking a course in OS.
My current crisis is in implementing a pipeline using C.

The implementation below allows TWO commands to be piped:
---------------------------------------------------------------------
main(int ac, char *av[]){

int p[2];
pipe(p);

if(fork( ) ){

dup2(p[1],1)
close(p[0]); close(p[1]);
execlp(av[1], av[1], 0);

}
else {

dup2(p[0],0);
close(p[0]); close(p[1]);
execlp(av[2],av[2],0);
}
}
---------------------------------------------------------
when the command is executed:
a.out who wc

the effect is the same as executing:
who | wc

The problem is to modify the above program such that the command:

a.out command1 command2 command3 ... commandN

has the same effect as:

command1 | command2 | command3 | ... | command N

using only the five system calls: dup2( ), pipe( ), execlp( ), fork( ), close( ).
Can any one help, pls?

no, we are not here to do your homework for you. if your uni is worth a light then they will have provided you with ample resources to deal with this assignment.