#include "apue.h"#define	MAXARGC		50	/* max number of arguments in buf */#define	WHITE	" \t\n"	/* white space for tokenizing arguments *//* * buf[] contains white-space-separated arguments.  We convert it to an * argv-style array of pointers, and call the user's function (optfunc) * to process the array.  We return -1 if there's a problem parsing buf, * else we return whatever optfunc() returns.  Note that user's buf[] * array is modified (nulls placed after each token). */intbuf_args(char *buf, int (*optfunc)(int, char **)){	char	*ptr, *argv[MAXARGC];	int		argc;	if (strtok(buf, WHITE) == NULL)		/* an argv[0] is required */		return(-1);	argv[argc = 0] = buf;	while ((ptr = strtok(NULL, WHITE)) != NULL) {		if (++argc >= MAXARGC-1)	/* -1 for room for NULL at end */			return(-1);		argv[argc] = ptr;	}	argv[++argc] = NULL;	/*	 * Since argv[] pointers point into the user's buf[],	 * user's function can just copy the pointers, even	 * though argv[] array will disappear on return.	 */	return((*optfunc)(argc, argv));}