/*  * This file is part of the UCB release of Plan 9. It is subject to the license * terms in the LICENSE file found in the top-level directory of this * distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No * part of the UCB release of Plan 9, including this file, may be copied, * modified, propagated, or distributed except according to the terms contained * in the LICENSE file. */ #include "rc.h"#include "exec.h"#include "io.h"#include "fns.h" struct here *here, **ehere;int ser = 0;char tmp[] = "/tmp/here0000.0000";char hex[] = "0123456789abcdef"; void psubst(io*, uchar*);void pstrs(io*, word*); voidhexnum(char *p, int n){	*p++ = hex[(n>>12)&0xF];	*p++ = hex[(n>>8)&0xF];	*p++ = hex[(n>>4)&0xF];	*p = hex[n&0xF];} tree*heredoc(tree *tag){	struct here *h = new(struct here); 	if(tag->type != WORD)		yyerror("Bad here tag");	h->next = 0;	if(here)		*ehere = h;	else		here = h;	ehere = &h->next;	h->tag = tag;	hexnum(&tmp[9], getpid());	hexnum(&tmp[14], ser++);	h->name = strdup(tmp);	return token(tmp, WORD);} /* * bug: lines longer than NLINE get split -- this can cause spurious * missubstitution, or a misrecognized EOF marker. */#define	NLINE	4096 voidreadhere(void){	int c, subst;	char *s, *tag;	char line[NLINE+1];	io *f;	struct here *h, *nexth; 	for(h = here; h; h = nexth){		subst = !h->tag->quoted;		tag = h->tag->str;		c = Creat(h->name);		if(c < 0)			yyerror("can't create here document");		f = openfd(c);		s = line;		pprompt();		while((c = rchr(runq->cmdfd)) != EOF){			if(c == '\n' || s == &line[NLINE]){				*s = '\0';				if(tag && strcmp(line, tag) == 0)					break;				if(subst)					psubst(f, (uchar *)line);				else					pstr(f, line);				s = line;				if(c == '\n'){					pprompt();					pchr(f, c);				}else					*s++ = c;			}else				*s++ = c;		}		flush(f);		closeio(f);		cleanhere(h->name);		nexth = h->next;		efree((char *)h);	}	here = 0;	doprompt = 1;} voidpsubst(io *f, uchar *s){	int savec, n;	uchar *t, *u;	Rune r;	word *star; 	while(*s){		if(*s != '$'){		/* copy plain text rune */			if(*s < Runeself)				pchr(f, *s++);			else{				n = chartorune(&r, (char *)s);				while(n-- > 0)					pchr(f, *s++);			}		}else{			/* $something -- perform substitution */			t = ++s;			if(*t == '$')				pchr(f, *t++);			else{				while(*t && idchr(*t))					t++;				savec = *t;				*t = '\0';				n = 0;				for(u = s; *u && '0' <= *u && *u <= '9'; u++)					n = n*10 + *u - '0';				if(n && *u == '\0'){					star = vlook("*")->val;					if(star && 1 <= n && n <= count(star)){						while(--n)							star = star->next;						pstr(f, star->word);					}				}else					pstrs(f, vlook((char *)s)->val);				*t = savec;				if(savec == '^')					t++;			}			s = t;		}	}} voidpstrs(io *f, word *a){	if(a){		while(a->next && a->next->word){			pstr(f, a->word);			pchr(f, ' ');			a = a->next;		}		pstr(f, a->word);	}}