#include	"mk.h"static	Word	*nextword(char**);Word*newword(char *s){	Word *w;	w = (Word *)Malloc(sizeof(Word));	w->s = strdup(s);	w->next = 0;	return(w);}Word *stow(char *s){	Word *head, *w, *new;	w = head = 0;	while(*s){		new = nextword(&s);		if(new == 0)			break;		if (w)			w->next = new;		else			head = w = new;		while(w->next)			w = w->next;			}	if (!head)		head = newword("");	return(head);}char *wtos(Word *w, int sep){	Bufblock *buf;	char *cp;	buf = newbuf();	for(; w; w = w->next){		for(cp = w->s; *cp; cp++)			insert(buf, *cp);		if(w->next)			insert(buf, sep);	}	insert(buf, 0);	cp = strdup(buf->start);	freebuf(buf);	return(cp);}Word*wdup(Word *w){	Word *v, *new, *base;	v = base = 0;	while(w){		new = newword(w->s);		if(v)			v->next = new;		else			base = new;		v = new;		w = w->next;	}	return base;}voiddelword(Word *w){	Word *v;	while(v = w){		w = w->next;		if(v->s)			free(v->s);		free(v);	}}/* *	break out a word from a string handling quotes, executions, *	and variable expansions. */static Word*nextword(char **s){	Bufblock *b;	Word *head, *tail, *w;	Rune r;	char *cp;	cp = *s;	b = newbuf();	head = tail = 0;	while(*cp == ' ' || *cp == '\t')		/* leading white space */		cp++;	while(*cp){		cp += chartorune(&r, cp);		switch(r)		{		case ' ':		case '\t':		case '\n':			goto out;		case '\\':		case '\'':		case '"':			cp = expandquote(cp, r, b);			if(cp == 0){				fprint(2, "missing closing quote: %s\n", *s);				Exit();			}			break;		case '$':			w = varsub(&cp);			if(w == 0)				break;			if(b->current != b->start){				bufcpy(b, w->s, strlen(w->s));				insert(b, 0);				free(w->s);				w->s = strdup(b->start);				b->current = b->start;			}			if(head){				bufcpy(b, tail->s, strlen(tail->s));				bufcpy(b, w->s, strlen(w->s));				insert(b, 0);				free(tail->s);				tail->s = strdup(b->start);				tail->next = w->next;				free(w->s);				free(w);				b->current = b->start;			} else				tail = head = w;			while(tail->next)				tail = tail->next;			break;		default:			rinsert(b, r);			break;		}	}out:	*s = cp;	if(b->current != b->start){		if(head){			cp = b->current;			bufcpy(b, tail->s, strlen(tail->s));			bufcpy(b, b->start, cp-b->start);			insert(b, 0);			free(tail->s);			tail->s = strdup(cp);		} else {			insert(b, 0);			head = newword(b->start);		}	}	freebuf(b);	return head;}voiddumpw(char *s, Word *w){	Bprint(&bout, "%s", s);	for(; w; w = w->next)		Bprint(&bout, " '%s'", w->s);	Bputc(&bout, '\n');}