What will be the output of the program?

#include<stdio.h>
#define PRINT(i) printf("%d,",i)

int main()
{
    int x=2, y=3, z=4;
    PRINT(x);
    PRINT(y);
    PRINT(z);
    return 0;
}

#include<stdio.h>

int main(int argc, char *argv, char *env[])
{
    int i;
    for(i=1; i<argc; i++)
        printf("%s\n", env[i]);
    return 0;
}

#include<stdio.h>
int fun(int, int);
typedef int (*pf) (int, int);
int proc(pf, int, int);

int main()
{
    printf("%d\n", proc(fun, 6, 6));
    return 0;
}
int fun(int a, int b)
{
   return (a==b);
}
int proc(pf p, int a, int b)
{
   return ((*p)(a, b));
}

#include<stdio.h>
int main()
{
    int *j;
    void fun(int**);
    fun(&j);
    return 0;
}
void fun(int **k)
{
    int a=10;
    /* Add a statement here */
}

/* sample.c */
#include<stdio.h>

int main(int argc, char *argv[])
{
    int i=0;
    i+=strlen(argv[1]);
    while(i>0)
    {
        printf("%c", argv[1][--i]);
    }
    return 0;
}

struct emp
{
    int ecode;
    struct emp *e;
};