include <unistd.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/wait.h>
int main(int argc, char* argv[])
{
   int pid = fork(), errno=-1;
   if(pid<0)
     return errno;
  else if(pid==0)
   {
       char *argv[]={"ls",NULL};
//       printf("%d            %d",getppid(),pid);       
execve("/bin/ls",argv,NULL);
       perror(NULL);
       printf("Child");
   }else {
   printf("Parent id %d \n CHild id  %d\n\n",getppid(),pid);
      wait(NULL);
      printf("Parent");
    }
}