#include "apue.h"intmain(int argc, char *argv[]){	int			i;	char		**ptr;	extern char	**environ;	for (i = 0; i < argc; i++)		/* echo all command-line args */		printf("argv[%d]: %s\n", i, argv[i]);	for (ptr = environ; *ptr != 0; ptr++)	/* and all env strings */		printf("%s\n", *ptr);	exit(0);}