parser.c revision 194765 
1/*-
2 * Copyright (c) 1991, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Kenneth Almquist.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 4. Neither the name of the University nor the names of its contributors
17 *    may be used to endorse or promote products derived from this software
18 *    without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33#ifndef lint
34#if 0
35static char sccsid[] = "@(#)parser.c	8.7 (Berkeley) 5/16/95";
36#endif
37#endif /* not lint */
38#include <sys/cdefs.h>
39__FBSDID("$FreeBSD: head/bin/sh/parser.c 194765 2009-06-23 20:45:12Z jilles $");
40
41#include <stdlib.h>
42#include <unistd.h>
43
44#include "shell.h"
45#include "parser.h"
46#include "nodes.h"
47#include "expand.h"	/* defines rmescapes() */
48#include "syntax.h"
49#include "options.h"
50#include "input.h"
51#include "output.h"
52#include "var.h"
53#include "error.h"
54#include "memalloc.h"
55#include "mystring.h"
56#include "alias.h"
57#include "show.h"
58#include "eval.h"
59#ifndef NO_HISTORY
60#include "myhistedit.h"
61#endif
62
63/*
64 * Shell command parser.
65 */
66
67#define	EOFMARKLEN	79
68#define	PROMPTLEN	128
69
70/* values returned by readtoken */
71#include "token.h"
72
73
74
75struct heredoc {
76	struct heredoc *next;	/* next here document in list */
77	union node *here;		/* redirection node */
78	char *eofmark;		/* string indicating end of input */
79	int striptabs;		/* if set, strip leading tabs */
80};
81
82
83
84STATIC struct heredoc *heredoclist;	/* list of here documents to read */
85STATIC int parsebackquote;	/* nonzero if we are inside backquotes */
86STATIC int doprompt;		/* if set, prompt the user */
87STATIC int needprompt;		/* true if interactive and at start of line */
88STATIC int lasttoken;		/* last token read */
89MKINIT int tokpushback;		/* last token pushed back */
90STATIC char *wordtext;		/* text of last word returned by readtoken */
91MKINIT int checkkwd;            /* 1 == check for kwds, 2 == also eat newlines */
92STATIC struct nodelist *backquotelist;
93STATIC union node *redirnode;
94STATIC struct heredoc *heredoc;
95STATIC int quoteflag;		/* set if (part of) last token was quoted */
96STATIC int startlinno;		/* line # where last token started */
97STATIC int funclinno;		/* line # where the current function started */
98
99/* XXX When 'noaliases' is set to one, no alias expansion takes place. */
100static int noaliases = 0;
101
102
103STATIC union node *list(int);
104STATIC union node *andor(void);
105STATIC union node *pipeline(void);
106STATIC union node *command(void);
107STATIC union node *simplecmd(union node **, union node *);
108STATIC union node *makename(void);
109STATIC void parsefname(void);
110STATIC void parseheredoc(void);
111STATIC int peektoken(void);
112STATIC int readtoken(void);
113STATIC int xxreadtoken(void);
114STATIC int readtoken1(int, char const *, char *, int);
115STATIC int noexpand(char *);
116STATIC void synexpect(int);
117STATIC void synerror(char *);
118STATIC void setprompt(int);
119
120
121/*
122 * Read and parse a command.  Returns NEOF on end of file.  (NULL is a
123 * valid parse tree indicating a blank line.)
124 */
125
126union node *
127parsecmd(int interact)
128{
129	int t;
130
131	tokpushback = 0;
132	doprompt = interact;
133	if (doprompt)
134		setprompt(1);
135	else
136		setprompt(0);
137	needprompt = 0;
138	t = readtoken();
139	if (t == TEOF)
140		return NEOF;
141	if (t == TNL)
142		return NULL;
143	tokpushback++;
144	return list(1);
145}
146
147
148STATIC union node *
149list(int nlflag)
150{
151	union node *n1, *n2, *n3;
152	int tok;
153
154	checkkwd = 2;
155	if (nlflag == 0 && tokendlist[peektoken()])
156		return NULL;
157	n1 = NULL;
158	for (;;) {
159		n2 = andor();
160		tok = readtoken();
161		if (tok == TBACKGND) {
162			if (n2->type == NCMD || n2->type == NPIPE) {
163				n2->ncmd.backgnd = 1;
164			} else if (n2->type == NREDIR) {
165				n2->type = NBACKGND;
166			} else {
167				n3 = (union node *)stalloc(sizeof (struct nredir));
168				n3->type = NBACKGND;
169				n3->nredir.n = n2;
170				n3->nredir.redirect = NULL;
171				n2 = n3;
172			}
173		}
174		if (n1 == NULL) {
175			n1 = n2;
176		}
177		else {
178			n3 = (union node *)stalloc(sizeof (struct nbinary));
179			n3->type = NSEMI;
180			n3->nbinary.ch1 = n1;
181			n3->nbinary.ch2 = n2;
182			n1 = n3;
183		}
184		switch (tok) {
185		case TBACKGND:
186		case TSEMI:
187			tok = readtoken();
188			/* FALLTHROUGH */
189		case TNL:
190			if (tok == TNL) {
191				parseheredoc();
192				if (nlflag)
193					return n1;
194			} else {
195				tokpushback++;
196			}
197			checkkwd = 2;
198			if (tokendlist[peektoken()])
199				return n1;
200			break;
201		case TEOF:
202			if (heredoclist)
203				parseheredoc();
204			else
205				pungetc();		/* push back EOF on input */
206			return n1;
207		default:
208			if (nlflag)
209				synexpect(-1);
210			tokpushback++;
211			return n1;
212		}
213	}
214}
215
216
217
218STATIC union node *
219andor(void)
220{
221	union node *n1, *n2, *n3;
222	int t;
223
224	n1 = pipeline();
225	for (;;) {
226		if ((t = readtoken()) == TAND) {
227			t = NAND;
228		} else if (t == TOR) {
229			t = NOR;
230		} else {
231			tokpushback++;
232			return n1;
233		}
234		n2 = pipeline();
235		n3 = (union node *)stalloc(sizeof (struct nbinary));
236		n3->type = t;
237		n3->nbinary.ch1 = n1;
238		n3->nbinary.ch2 = n2;
239		n1 = n3;
240	}
241}
242
243
244
245STATIC union node *
246pipeline(void)
247{
248	union node *n1, *n2, *pipenode;
249	struct nodelist *lp, *prev;
250	int negate;
251
252	negate = 0;
253	checkkwd = 2;
254	TRACE(("pipeline: entered\n"));
255	while (readtoken() == TNOT)
256		negate = !negate;
257	tokpushback++;
258	n1 = command();
259	if (readtoken() == TPIPE) {
260		pipenode = (union node *)stalloc(sizeof (struct npipe));
261		pipenode->type = NPIPE;
262		pipenode->npipe.backgnd = 0;
263		lp = (struct nodelist *)stalloc(sizeof (struct nodelist));
264		pipenode->npipe.cmdlist = lp;
265		lp->n = n1;
266		do {
267			prev = lp;
268			lp = (struct nodelist *)stalloc(sizeof (struct nodelist));
269			lp->n = command();
270			prev->next = lp;
271		} while (readtoken() == TPIPE);
272		lp->next = NULL;
273		n1 = pipenode;
274	}
275	tokpushback++;
276	if (negate) {
277		n2 = (union node *)stalloc(sizeof (struct nnot));
278		n2->type = NNOT;
279		n2->nnot.com = n1;
280		return n2;
281	} else
282		return n1;
283}
284
285
286
287STATIC union node *
288command(void)
289{
290	union node *n1, *n2;
291	union node *ap, **app;
292	union node *cp, **cpp;
293	union node *redir, **rpp;
294	int t, negate = 0;
295
296	checkkwd = 2;
297	redir = NULL;
298	n1 = NULL;
299	rpp = &redir;
300
301	/* Check for redirection which may precede command */
302	while (readtoken() == TREDIR) {
303		*rpp = n2 = redirnode;
304		rpp = &n2->nfile.next;
305		parsefname();
306	}
307	tokpushback++;
308
309	while (readtoken() == TNOT) {
310		TRACE(("command: TNOT recognized\n"));
311		negate = !negate;
312	}
313	tokpushback++;
314
315	switch (readtoken()) {
316	case TIF:
317		n1 = (union node *)stalloc(sizeof (struct nif));
318		n1->type = NIF;
319		if ((n1->nif.test = list(0)) == NULL)
320			synexpect(-1);
321		if (readtoken() != TTHEN)
322			synexpect(TTHEN);
323		n1->nif.ifpart = list(0);
324		n2 = n1;
325		while (readtoken() == TELIF) {
326			n2->nif.elsepart = (union node *)stalloc(sizeof (struct nif));
327			n2 = n2->nif.elsepart;
328			n2->type = NIF;
329			if ((n2->nif.test = list(0)) == NULL)
330				synexpect(-1);
331			if (readtoken() != TTHEN)
332				synexpect(TTHEN);
333			n2->nif.ifpart = list(0);
334		}
335		if (lasttoken == TELSE)
336			n2->nif.elsepart = list(0);
337		else {
338			n2->nif.elsepart = NULL;
339			tokpushback++;
340		}
341		if (readtoken() != TFI)
342			synexpect(TFI);
343		checkkwd = 1;
344		break;
345	case TWHILE:
346	case TUNTIL: {
347		int got;
348		n1 = (union node *)stalloc(sizeof (struct nbinary));
349		n1->type = (lasttoken == TWHILE)? NWHILE : NUNTIL;
350		if ((n1->nbinary.ch1 = list(0)) == NULL)
351			synexpect(-1);
352		if ((got=readtoken()) != TDO) {
353TRACE(("expecting DO got %s %s\n", tokname[got], got == TWORD ? wordtext : ""));
354			synexpect(TDO);
355		}
356		n1->nbinary.ch2 = list(0);
357		if (readtoken() != TDONE)
358			synexpect(TDONE);
359		checkkwd = 1;
360		break;
361	}
362	case TFOR:
363		if (readtoken() != TWORD || quoteflag || ! goodname(wordtext))
364			synerror("Bad for loop variable");
365		n1 = (union node *)stalloc(sizeof (struct nfor));
366		n1->type = NFOR;
367		n1->nfor.var = wordtext;
368		if (readtoken() == TWORD && ! quoteflag && equal(wordtext, "in")) {
369			app = &ap;
370			while (readtoken() == TWORD) {
371				n2 = (union node *)stalloc(sizeof (struct narg));
372				n2->type = NARG;
373				n2->narg.text = wordtext;
374				n2->narg.backquote = backquotelist;
375				*app = n2;
376				app = &n2->narg.next;
377			}
378			*app = NULL;
379			n1->nfor.args = ap;
380			if (lasttoken != TNL && lasttoken != TSEMI)
381				synexpect(-1);
382		} else {
383			static char argvars[5] = {
384				CTLVAR, VSNORMAL|VSQUOTE, '@', '=', '\0'
385			};
386			n2 = (union node *)stalloc(sizeof (struct narg));
387			n2->type = NARG;
388			n2->narg.text = argvars;
389			n2->narg.backquote = NULL;
390			n2->narg.next = NULL;
391			n1->nfor.args = n2;
392			/*
393			 * Newline or semicolon here is optional (but note
394			 * that the original Bourne shell only allowed NL).
395			 */
396			if (lasttoken != TNL && lasttoken != TSEMI)
397				tokpushback++;
398		}
399		checkkwd = 2;
400		if ((t = readtoken()) == TDO)
401			t = TDONE;
402		else if (t == TBEGIN)
403			t = TEND;
404		else
405			synexpect(-1);
406		n1->nfor.body = list(0);
407		if (readtoken() != t)
408			synexpect(t);
409		checkkwd = 1;
410		break;
411	case TCASE:
412		n1 = (union node *)stalloc(sizeof (struct ncase));
413		n1->type = NCASE;
414		if (readtoken() != TWORD)
415			synexpect(TWORD);
416		n1->ncase.expr = n2 = (union node *)stalloc(sizeof (struct narg));
417		n2->type = NARG;
418		n2->narg.text = wordtext;
419		n2->narg.backquote = backquotelist;
420		n2->narg.next = NULL;
421		while (readtoken() == TNL);
422		if (lasttoken != TWORD || ! equal(wordtext, "in"))
423			synerror("expecting \"in\"");
424		cpp = &n1->ncase.cases;
425		noaliases = 1;	/* turn off alias expansion */
426		checkkwd = 2, readtoken();
427		while (lasttoken != TESAC) {
428			*cpp = cp = (union node *)stalloc(sizeof (struct nclist));
429			cp->type = NCLIST;
430			app = &cp->nclist.pattern;
431			if (lasttoken == TLP)
432				readtoken();
433			for (;;) {
434				*app = ap = (union node *)stalloc(sizeof (struct narg));
435				ap->type = NARG;
436				ap->narg.text = wordtext;
437				ap->narg.backquote = backquotelist;
438				if (checkkwd = 2, readtoken() != TPIPE)
439					break;
440				app = &ap->narg.next;
441				readtoken();
442			}
443			ap->narg.next = NULL;
444			if (lasttoken != TRP)
445				noaliases = 0, synexpect(TRP);
446			cp->nclist.body = list(0);
447
448			checkkwd = 2;
449			if ((t = readtoken()) != TESAC) {
450				if (t != TENDCASE)
451					noaliases = 0, synexpect(TENDCASE);
452				else
453					checkkwd = 2, readtoken();
454			}
455			cpp = &cp->nclist.next;
456		}
457		noaliases = 0;	/* reset alias expansion */
458		*cpp = NULL;
459		checkkwd = 1;
460		break;
461	case TLP:
462		n1 = (union node *)stalloc(sizeof (struct nredir));
463		n1->type = NSUBSHELL;
464		n1->nredir.n = list(0);
465		n1->nredir.redirect = NULL;
466		if (readtoken() != TRP)
467			synexpect(TRP);
468		checkkwd = 1;
469		break;
470	case TBEGIN:
471		n1 = list(0);
472		if (readtoken() != TEND)
473			synexpect(TEND);
474		checkkwd = 1;
475		break;
476	/* Handle an empty command like other simple commands.  */
477	case TSEMI:
478	case TAND:
479	case TOR:
480		/*
481		 * An empty command before a ; doesn't make much sense, and
482		 * should certainly be disallowed in the case of `if ;'.
483		 */
484		if (!redir)
485			synexpect(-1);
486	case TNL:
487	case TEOF:
488	case TWORD:
489	case TRP:
490		tokpushback++;
491		n1 = simplecmd(rpp, redir);
492		goto checkneg;
493	default:
494		synexpect(-1);
495	}
496
497	/* Now check for redirection which may follow command */
498	while (readtoken() == TREDIR) {
499		*rpp = n2 = redirnode;
500		rpp = &n2->nfile.next;
501		parsefname();
502	}
503	tokpushback++;
504	*rpp = NULL;
505	if (redir) {
506		if (n1->type != NSUBSHELL) {
507			n2 = (union node *)stalloc(sizeof (struct nredir));
508			n2->type = NREDIR;
509			n2->nredir.n = n1;
510			n1 = n2;
511		}
512		n1->nredir.redirect = redir;
513	}
514
515checkneg:
516	if (negate) {
517		n2 = (union node *)stalloc(sizeof (struct nnot));
518		n2->type = NNOT;
519		n2->nnot.com = n1;
520		return n2;
521	}
522	else
523		return n1;
524}
525
526
527STATIC union node *
528simplecmd(union node **rpp, union node *redir)
529{
530	union node *args, **app;
531	union node **orig_rpp = rpp;
532	union node *n = NULL, *n2;
533	int negate = 0;
534
535	/* If we don't have any redirections already, then we must reset */
536	/* rpp to be the address of the local redir variable.  */
537	if (redir == 0)
538		rpp = &redir;
539
540	args = NULL;
541	app = &args;
542	/*
543	 * We save the incoming value, because we need this for shell
544	 * functions.  There can not be a redirect or an argument between
545	 * the function name and the open parenthesis.
546	 */
547	orig_rpp = rpp;
548
549	while (readtoken() == TNOT) {
550		TRACE(("command: TNOT recognized\n"));
551		negate = !negate;
552	}
553	tokpushback++;
554
555	for (;;) {
556		if (readtoken() == TWORD) {
557			n = (union node *)stalloc(sizeof (struct narg));
558			n->type = NARG;
559			n->narg.text = wordtext;
560			n->narg.backquote = backquotelist;
561			*app = n;
562			app = &n->narg.next;
563		} else if (lasttoken == TREDIR) {
564			*rpp = n = redirnode;
565			rpp = &n->nfile.next;
566			parsefname();	/* read name of redirection file */
567		} else if (lasttoken == TLP && app == &args->narg.next
568					    && rpp == orig_rpp) {
569			/* We have a function */
570			if (readtoken() != TRP)
571				synexpect(TRP);
572			funclinno = plinno;
573#ifdef notdef
574			if (! goodname(n->narg.text))
575				synerror("Bad function name");
576#endif
577			n->type = NDEFUN;
578			n->narg.next = command();
579			funclinno = 0;
580			goto checkneg;
581		} else {
582			tokpushback++;
583			break;
584		}
585	}
586	*app = NULL;
587	*rpp = NULL;
588	n = (union node *)stalloc(sizeof (struct ncmd));
589	n->type = NCMD;
590	n->ncmd.backgnd = 0;
591	n->ncmd.args = args;
592	n->ncmd.redirect = redir;
593
594checkneg:
595	if (negate) {
596		n2 = (union node *)stalloc(sizeof (struct nnot));
597		n2->type = NNOT;
598		n2->nnot.com = n;
599		return n2;
600	}
601	else
602		return n;
603}
604
605STATIC union node *
606makename(void)
607{
608	union node *n;
609
610	n = (union node *)stalloc(sizeof (struct narg));
611	n->type = NARG;
612	n->narg.next = NULL;
613	n->narg.text = wordtext;
614	n->narg.backquote = backquotelist;
615	return n;
616}
617
618void fixredir(union node *n, const char *text, int err)
619{
620	TRACE(("Fix redir %s %d\n", text, err));
621	if (!err)
622		n->ndup.vname = NULL;
623
624	if (is_digit(text[0]) && text[1] == '\0')
625		n->ndup.dupfd = digit_val(text[0]);
626	else if (text[0] == '-' && text[1] == '\0')
627		n->ndup.dupfd = -1;
628	else {
629
630		if (err)
631			synerror("Bad fd number");
632		else
633			n->ndup.vname = makename();
634	}
635}
636
637
638STATIC void
639parsefname(void)
640{
641	union node *n = redirnode;
642
643	if (readtoken() != TWORD)
644		synexpect(-1);
645	if (n->type == NHERE) {
646		struct heredoc *here = heredoc;
647		struct heredoc *p;
648		int i;
649
650		if (quoteflag == 0)
651			n->type = NXHERE;
652		TRACE(("Here document %d\n", n->type));
653		if (here->striptabs) {
654			while (*wordtext == '\t')
655				wordtext++;
656		}
657		if (! noexpand(wordtext) || (i = strlen(wordtext)) == 0 || i > EOFMARKLEN)
658			synerror("Illegal eof marker for << redirection");
659		rmescapes(wordtext);
660		here->eofmark = wordtext;
661		here->next = NULL;
662		if (heredoclist == NULL)
663			heredoclist = here;
664		else {
665			for (p = heredoclist ; p->next ; p = p->next);
666			p->next = here;
667		}
668	} else if (n->type == NTOFD || n->type == NFROMFD) {
669		fixredir(n, wordtext, 0);
670	} else {
671		n->nfile.fname = makename();
672	}
673}
674
675
676/*
677 * Input any here documents.
678 */
679
680STATIC void
681parseheredoc(void)
682{
683	struct heredoc *here;
684	union node *n;
685
686	while (heredoclist) {
687		here = heredoclist;
688		heredoclist = here->next;
689		if (needprompt) {
690			setprompt(2);
691			needprompt = 0;
692		}
693		readtoken1(pgetc(), here->here->type == NHERE? SQSYNTAX : DQSYNTAX,
694				here->eofmark, here->striptabs);
695		n = (union node *)stalloc(sizeof (struct narg));
696		n->narg.type = NARG;
697		n->narg.next = NULL;
698		n->narg.text = wordtext;
699		n->narg.backquote = backquotelist;
700		here->here->nhere.doc = n;
701	}
702}
703
704STATIC int
705peektoken(void)
706{
707	int t;
708
709	t = readtoken();
710	tokpushback++;
711	return (t);
712}
713
714STATIC int
715readtoken(void)
716{
717	int t;
718	int savecheckkwd = checkkwd;
719	struct alias *ap;
720#ifdef DEBUG
721	int alreadyseen = tokpushback;
722#endif
723
724	top:
725	t = xxreadtoken();
726
727	if (checkkwd) {
728		/*
729		 * eat newlines
730		 */
731		if (checkkwd == 2) {
732			checkkwd = 0;
733			while (t == TNL) {
734				parseheredoc();
735				t = xxreadtoken();
736			}
737		} else
738			checkkwd = 0;
739		/*
740		 * check for keywords and aliases
741		 */
742		if (t == TWORD && !quoteflag)
743		{
744			const char * const *pp;
745
746			for (pp = parsekwd; *pp; pp++) {
747				if (**pp == *wordtext && equal(*pp, wordtext))
748				{
749					lasttoken = t = pp - parsekwd + KWDOFFSET;
750					TRACE(("keyword %s recognized\n", tokname[t]));
751					goto out;
752				}
753			}
754			if (noaliases == 0 &&
755			    (ap = lookupalias(wordtext, 1)) != NULL) {
756				pushstring(ap->val, strlen(ap->val), ap);
757				checkkwd = savecheckkwd;
758				goto top;
759			}
760		}
761out:
762		checkkwd = (t == TNOT) ? savecheckkwd : 0;
763	}
764#ifdef DEBUG
765	if (!alreadyseen)
766	    TRACE(("token %s %s\n", tokname[t], t == TWORD ? wordtext : ""));
767	else
768	    TRACE(("reread token %s %s\n", tokname[t], t == TWORD ? wordtext : ""));
769#endif
770	return (t);
771}
772
773
774/*
775 * Read the next input token.
776 * If the token is a word, we set backquotelist to the list of cmds in
777 *	backquotes.  We set quoteflag to true if any part of the word was
778 *	quoted.
779 * If the token is TREDIR, then we set redirnode to a structure containing
780 *	the redirection.
781 * In all cases, the variable startlinno is set to the number of the line
782 *	on which the token starts.
783 *
784 * [Change comment:  here documents and internal procedures]
785 * [Readtoken shouldn't have any arguments.  Perhaps we should make the
786 *  word parsing code into a separate routine.  In this case, readtoken
787 *  doesn't need to have any internal procedures, but parseword does.
788 *  We could also make parseoperator in essence the main routine, and
789 *  have parseword (readtoken1?) handle both words and redirection.]
790 */
791
792#define RETURN(token)	return lasttoken = token
793
794STATIC int
795xxreadtoken(void)
796{
797	int c;
798
799	if (tokpushback) {
800		tokpushback = 0;
801		return lasttoken;
802	}
803	if (needprompt) {
804		setprompt(2);
805		needprompt = 0;
806	}
807	startlinno = plinno;
808	for (;;) {	/* until token or start of word found */
809		c = pgetc_macro();
810		if (c == ' ' || c == '\t')
811			continue;		/* quick check for white space first */
812		switch (c) {
813		case ' ': case '\t':
814			continue;
815		case '#':
816			while ((c = pgetc()) != '\n' && c != PEOF);
817			pungetc();
818			continue;
819		case '\\':
820			if (pgetc() == '\n') {
821				startlinno = ++plinno;
822				if (doprompt)
823					setprompt(2);
824				else
825					setprompt(0);
826				continue;
827			}
828			pungetc();
829			goto breakloop;
830		case '\n':
831			plinno++;
832			needprompt = doprompt;
833			RETURN(TNL);
834		case PEOF:
835			RETURN(TEOF);
836		case '&':
837			if (pgetc() == '&')
838				RETURN(TAND);
839			pungetc();
840			RETURN(TBACKGND);
841		case '|':
842			if (pgetc() == '|')
843				RETURN(TOR);
844			pungetc();
845			RETURN(TPIPE);
846		case ';':
847			if (pgetc() == ';')
848				RETURN(TENDCASE);
849			pungetc();
850			RETURN(TSEMI);
851		case '(':
852			RETURN(TLP);
853		case ')':
854			RETURN(TRP);
855		default:
856			goto breakloop;
857		}
858	}
859breakloop:
860	return readtoken1(c, BASESYNTAX, (char *)NULL, 0);
861#undef RETURN
862}
863
864
865
866/*
867 * If eofmark is NULL, read a word or a redirection symbol.  If eofmark
868 * is not NULL, read a here document.  In the latter case, eofmark is the
869 * word which marks the end of the document and striptabs is true if
870 * leading tabs should be stripped from the document.  The argument firstc
871 * is the first character of the input token or document.
872 *
873 * Because C does not have internal subroutines, I have simulated them
874 * using goto's to implement the subroutine linkage.  The following macros
875 * will run code that appears at the end of readtoken1.
876 */
877
878#define CHECKEND()	{goto checkend; checkend_return:;}
879#define PARSEREDIR()	{goto parseredir; parseredir_return:;}
880#define PARSESUB()	{goto parsesub; parsesub_return:;}
881#define PARSEBACKQOLD()	{oldstyle = 1; goto parsebackq; parsebackq_oldreturn:;}
882#define PARSEBACKQNEW()	{oldstyle = 0; goto parsebackq; parsebackq_newreturn:;}
883#define	PARSEARITH()	{goto parsearith; parsearith_return:;}
884
885STATIC int
886readtoken1(int firstc, char const *syntax, char *eofmark, int striptabs)
887{
888	int c = firstc;
889	char *out;
890	int len;
891	char line[EOFMARKLEN + 1];
892	struct nodelist *bqlist;
893	int quotef;
894	int dblquote;
895	int varnest;	/* levels of variables expansion */
896	int arinest;	/* levels of arithmetic expansion */
897	int parenlevel;	/* levels of parens in arithmetic */
898	int oldstyle;
899	char const *prevsyntax;	/* syntax before arithmetic */
900	int synentry;
901
902	startlinno = plinno;
903	dblquote = 0;
904	if (syntax == DQSYNTAX)
905		dblquote = 1;
906	quotef = 0;
907	bqlist = NULL;
908	varnest = 0;
909	arinest = 0;
910	parenlevel = 0;
911
912	STARTSTACKSTR(out);
913	loop: {	/* for each line, until end of word */
914		CHECKEND();	/* set c to PEOF if at end of here document */
915		for (;;) {	/* until end of line or end of word */
916			CHECKSTRSPACE(3, out);	/* permit 3 calls to USTPUTC */
917
918			synentry = syntax[c];
919
920			switch(synentry) {
921			case CNL:	/* '\n' */
922				if (syntax == BASESYNTAX)
923					goto endword;	/* exit outer loop */
924				USTPUTC(c, out);
925				plinno++;
926				if (doprompt)
927					setprompt(2);
928				else
929					setprompt(0);
930				c = pgetc();
931				goto loop;		/* continue outer loop */
932			case CWORD:
933				USTPUTC(c, out);
934				break;
935			case CCTL:
936				if (eofmark == NULL || dblquote)
937					USTPUTC(CTLESC, out);
938				USTPUTC(c, out);
939				break;
940			case CBACK:	/* backslash */
941				c = pgetc();
942				if (c == PEOF) {
943					USTPUTC('\\', out);
944					pungetc();
945				} else if (c == '\n') {
946					plinno++;
947					if (doprompt)
948						setprompt(2);
949					else
950						setprompt(0);
951				} else {
952					if (dblquote && c != '\\' &&
953					    c != '`' && c != '$' &&
954					    (c != '"' || eofmark != NULL))
955						USTPUTC('\\', out);
956					if (SQSYNTAX[c] == CCTL)
957						USTPUTC(CTLESC, out);
958					else if (eofmark == NULL)
959						USTPUTC(CTLQUOTEMARK, out);
960					USTPUTC(c, out);
961					quotef++;
962				}
963				break;
964			case CSQUOTE:
965				if (eofmark == NULL)
966					USTPUTC(CTLQUOTEMARK, out);
967				syntax = SQSYNTAX;
968				break;
969			case CDQUOTE:
970				if (eofmark == NULL)
971					USTPUTC(CTLQUOTEMARK, out);
972				syntax = DQSYNTAX;
973				dblquote = 1;
974				break;
975			case CENDQUOTE:
976				if (eofmark != NULL && arinest == 0 &&
977				    varnest == 0) {
978					USTPUTC(c, out);
979				} else {
980					if (arinest) {
981						syntax = ARISYNTAX;
982						dblquote = 0;
983					} else if (eofmark == NULL) {
984						syntax = BASESYNTAX;
985						dblquote = 0;
986					}
987					quotef++;
988				}
989				break;
990			case CVAR:	/* '$' */
991				PARSESUB();		/* parse substitution */
992				break;
993			case CENDVAR:	/* '}' */
994				if (varnest > 0) {
995					varnest--;
996					USTPUTC(CTLENDVAR, out);
997				} else {
998					USTPUTC(c, out);
999				}
1000				break;
1001			case CLP:	/* '(' in arithmetic */
1002				parenlevel++;
1003				USTPUTC(c, out);
1004				break;
1005			case CRP:	/* ')' in arithmetic */
1006				if (parenlevel > 0) {
1007					USTPUTC(c, out);
1008					--parenlevel;
1009				} else {
1010					if (pgetc() == ')') {
1011						if (--arinest == 0) {
1012							USTPUTC(CTLENDARI, out);
1013							syntax = prevsyntax;
1014							if (syntax == DQSYNTAX)
1015								dblquote = 1;
1016							else
1017								dblquote = 0;
1018						} else
1019							USTPUTC(')', out);
1020					} else {
1021						/*
1022						 * unbalanced parens
1023						 *  (don't 2nd guess - no error)
1024						 */
1025						pungetc();
1026						USTPUTC(')', out);
1027					}
1028				}
1029				break;
1030			case CBQUOTE:	/* '`' */
1031				PARSEBACKQOLD();
1032				break;
1033			case CEOF:
1034				goto endword;		/* exit outer loop */
1035			default:
1036				if (varnest == 0)
1037					goto endword;	/* exit outer loop */
1038				USTPUTC(c, out);
1039			}
1040			c = pgetc_macro();
1041		}
1042	}
1043endword:
1044	if (syntax == ARISYNTAX)
1045		synerror("Missing '))'");
1046	if (syntax != BASESYNTAX && ! parsebackquote && eofmark == NULL)
1047		synerror("Unterminated quoted string");
1048	if (varnest != 0) {
1049		startlinno = plinno;
1050		synerror("Missing '}'");
1051	}
1052	USTPUTC('\0', out);
1053	len = out - stackblock();
1054	out = stackblock();
1055	if (eofmark == NULL) {
1056		if ((c == '>' || c == '<')
1057		 && quotef == 0
1058		 && len <= 2
1059		 && (*out == '\0' || is_digit(*out))) {
1060			PARSEREDIR();
1061			return lasttoken = TREDIR;
1062		} else {
1063			pungetc();
1064		}
1065	}
1066	quoteflag = quotef;
1067	backquotelist = bqlist;
1068	grabstackblock(len);
1069	wordtext = out;
1070	return lasttoken = TWORD;
1071/* end of readtoken routine */
1072
1073
1074
1075/*
1076 * Check to see whether we are at the end of the here document.  When this
1077 * is called, c is set to the first character of the next input line.  If
1078 * we are at the end of the here document, this routine sets the c to PEOF.
1079 */
1080
1081checkend: {
1082	if (eofmark) {
1083		if (striptabs) {
1084			while (c == '\t')
1085				c = pgetc();
1086		}
1087		if (c == *eofmark) {
1088			if (pfgets(line, sizeof line) != NULL) {
1089				char *p, *q;
1090
1091				p = line;
1092				for (q = eofmark + 1 ; *q && *p == *q ; p++, q++);
1093				if (*p == '\n' && *q == '\0') {
1094					c = PEOF;
1095					plinno++;
1096					needprompt = doprompt;
1097				} else {
1098					pushstring(line, strlen(line), NULL);
1099				}
1100			}
1101		}
1102	}
1103	goto checkend_return;
1104}
1105
1106
1107/*
1108 * Parse a redirection operator.  The variable "out" points to a string
1109 * specifying the fd to be redirected.  The variable "c" contains the
1110 * first character of the redirection operator.
1111 */
1112
1113parseredir: {
1114	char fd = *out;
1115	union node *np;
1116
1117	np = (union node *)stalloc(sizeof (struct nfile));
1118	if (c == '>') {
1119		np->nfile.fd = 1;
1120		c = pgetc();
1121		if (c == '>')
1122			np->type = NAPPEND;
1123		else if (c == '&')
1124			np->type = NTOFD;
1125		else if (c == '|')
1126			np->type = NCLOBBER;
1127		else {
1128			np->type = NTO;
1129			pungetc();
1130		}
1131	} else {	/* c == '<' */
1132		np->nfile.fd = 0;
1133		c = pgetc();
1134		if (c == '<') {
1135			if (sizeof (struct nfile) != sizeof (struct nhere)) {
1136				np = (union node *)stalloc(sizeof (struct nhere));
1137				np->nfile.fd = 0;
1138			}
1139			np->type = NHERE;
1140			heredoc = (struct heredoc *)stalloc(sizeof (struct heredoc));
1141			heredoc->here = np;
1142			if ((c = pgetc()) == '-') {
1143				heredoc->striptabs = 1;
1144			} else {
1145				heredoc->striptabs = 0;
1146				pungetc();
1147			}
1148		} else if (c == '&')
1149			np->type = NFROMFD;
1150		else if (c == '>')
1151			np->type = NFROMTO;
1152		else {
1153			np->type = NFROM;
1154			pungetc();
1155		}
1156	}
1157	if (fd != '\0')
1158		np->nfile.fd = digit_val(fd);
1159	redirnode = np;
1160	goto parseredir_return;
1161}
1162
1163
1164/*
1165 * Parse a substitution.  At this point, we have read the dollar sign
1166 * and nothing else.
1167 */
1168
1169parsesub: {
1170	char buf[10];
1171	int subtype;
1172	int typeloc;
1173	int flags;
1174	char *p;
1175	static const char types[] = "}-+?=";
1176	int bracketed_name = 0; /* used to handle ${[0-9]*} variables */
1177	int i;
1178	int linno;
1179	int length;
1180
1181	c = pgetc();
1182	if (c != '(' && c != '{' && (is_eof(c) || !is_name(c)) &&
1183	    !is_special(c)) {
1184		USTPUTC('$', out);
1185		pungetc();
1186	} else if (c == '(') {	/* $(command) or $((arith)) */
1187		if (pgetc() == '(') {
1188			PARSEARITH();
1189		} else {
1190			pungetc();
1191			PARSEBACKQNEW();
1192		}
1193	} else {
1194		USTPUTC(CTLVAR, out);
1195		typeloc = out - stackblock();
1196		USTPUTC(VSNORMAL, out);
1197		subtype = VSNORMAL;
1198		flags = 0;
1199		if (c == '{') {
1200			bracketed_name = 1;
1201			c = pgetc();
1202			if (c == '#') {
1203				if ((c = pgetc()) == '}')
1204					c = '#';
1205				else
1206					subtype = VSLENGTH;
1207			}
1208			else
1209				subtype = 0;
1210		}
1211		if (!is_eof(c) && is_name(c)) {
1212			length = 0;
1213			do {
1214				STPUTC(c, out);
1215				c = pgetc();
1216				length++;
1217			} while (!is_eof(c) && is_in_name(c));
1218			if (length == 6 &&
1219			    strncmp(out - length, "LINENO", length) == 0) {
1220				/* Replace the variable name with the
1221				 * current line number. */
1222				linno = plinno;
1223				if (funclinno != 0)
1224					linno -= funclinno - 1;
1225				snprintf(buf, sizeof(buf), "%d", linno);
1226				STADJUST(-6, out);
1227				for (i = 0; buf[i] != '\0'; i++)
1228					STPUTC(buf[i], out);
1229				flags |= VSLINENO;
1230			}
1231		} else if (is_digit(c)) {
1232			if (bracketed_name) {
1233				do {
1234					STPUTC(c, out);
1235					c = pgetc();
1236				} while (is_digit(c));
1237			} else {
1238				STPUTC(c, out);
1239				c = pgetc();
1240			}
1241		} else {
1242			if (! is_special(c)) {
1243				subtype = VSERROR;
1244				if (c == '}')
1245					pungetc();
1246				else
1247					USTPUTC(c, out);
1248			} else {
1249				USTPUTC(c, out);
1250				c = pgetc();
1251			}
1252		}
1253		if (subtype == 0) {
1254			switch (c) {
1255			case ':':
1256				flags |= VSNUL;
1257				c = pgetc();
1258				/*FALLTHROUGH*/
1259			default:
1260				p = strchr(types, c);
1261				if (p == NULL) {
1262					if (flags == VSNUL)
1263						STPUTC(':', out);
1264					STPUTC(c, out);
1265					subtype = VSERROR;
1266				} else
1267					subtype = p - types + VSNORMAL;
1268				break;
1269			case '%':
1270			case '#':
1271				{
1272					int cc = c;
1273					subtype = c == '#' ? VSTRIMLEFT :
1274							     VSTRIMRIGHT;
1275					c = pgetc();
1276					if (c == cc)
1277						subtype++;
1278					else
1279						pungetc();
1280					break;
1281				}
1282			}
1283		} else if (subtype != VSERROR) {
1284			pungetc();
1285		}
1286		STPUTC('=', out);
1287		if (subtype != VSLENGTH && (dblquote || arinest))
1288			flags |= VSQUOTE;
1289		*(stackblock() + typeloc) = subtype | flags;
1290		if (subtype != VSNORMAL)
1291			varnest++;
1292	}
1293	goto parsesub_return;
1294}
1295
1296
1297/*
1298 * Called to parse command substitutions.  Newstyle is set if the command
1299 * is enclosed inside $(...); nlpp is a pointer to the head of the linked
1300 * list of commands (passed by reference), and savelen is the number of
1301 * characters on the top of the stack which must be preserved.
1302 */
1303
1304parsebackq: {
1305	struct nodelist **nlpp;
1306	int savepbq;
1307	union node *n;
1308	char *volatile str;
1309	struct jmploc jmploc;
1310	struct jmploc *const savehandler = handler;
1311	int savelen;
1312	int saveprompt;
1313
1314	savepbq = parsebackquote;
1315	if (setjmp(jmploc.loc)) {
1316		if (str)
1317			ckfree(str);
1318		parsebackquote = 0;
1319		handler = savehandler;
1320		longjmp(handler->loc, 1);
1321	}
1322	INTOFF;
1323	str = NULL;
1324	savelen = out - stackblock();
1325	if (savelen > 0) {
1326		str = ckmalloc(savelen);
1327		memcpy(str, stackblock(), savelen);
1328	}
1329	handler = &jmploc;
1330	INTON;
1331        if (oldstyle) {
1332                /* We must read until the closing backquote, giving special
1333                   treatment to some slashes, and then push the string and
1334                   reread it as input, interpreting it normally.  */
1335                char *out;
1336                int c;
1337                int savelen;
1338                char *str;
1339
1340
1341                STARTSTACKSTR(out);
1342		for (;;) {
1343			if (needprompt) {
1344				setprompt(2);
1345				needprompt = 0;
1346			}
1347			switch (c = pgetc()) {
1348			case '`':
1349				goto done;
1350
1351			case '\\':
1352                                if ((c = pgetc()) == '\n') {
1353					plinno++;
1354					if (doprompt)
1355						setprompt(2);
1356					else
1357						setprompt(0);
1358					/*
1359					 * If eating a newline, avoid putting
1360					 * the newline into the new character
1361					 * stream (via the STPUTC after the
1362					 * switch).
1363					 */
1364					continue;
1365				}
1366                                if (c != '\\' && c != '`' && c != '$'
1367                                    && (!dblquote || c != '"'))
1368                                        STPUTC('\\', out);
1369				break;
1370
1371			case '\n':
1372				plinno++;
1373				needprompt = doprompt;
1374				break;
1375
1376			case PEOF:
1377			        startlinno = plinno;
1378				synerror("EOF in backquote substitution");
1379 				break;
1380
1381			default:
1382				break;
1383			}
1384			STPUTC(c, out);
1385                }
1386done:
1387                STPUTC('\0', out);
1388                savelen = out - stackblock();
1389                if (savelen > 0) {
1390                        str = ckmalloc(savelen);
1391                        memcpy(str, stackblock(), savelen);
1392			setinputstring(str, 1);
1393                }
1394        }
1395	nlpp = &bqlist;
1396	while (*nlpp)
1397		nlpp = &(*nlpp)->next;
1398	*nlpp = (struct nodelist *)stalloc(sizeof (struct nodelist));
1399	(*nlpp)->next = NULL;
1400	parsebackquote = oldstyle;
1401
1402	if (oldstyle) {
1403		saveprompt = doprompt;
1404		doprompt = 0;
1405	}
1406
1407	n = list(0);
1408
1409	if (oldstyle)
1410		doprompt = saveprompt;
1411	else {
1412		if (readtoken() != TRP)
1413			synexpect(TRP);
1414	}
1415
1416	(*nlpp)->n = n;
1417        if (oldstyle) {
1418		/*
1419		 * Start reading from old file again, ignoring any pushed back
1420		 * tokens left from the backquote parsing
1421		 */
1422                popfile();
1423		tokpushback = 0;
1424	}
1425	while (stackblocksize() <= savelen)
1426		growstackblock();
1427	STARTSTACKSTR(out);
1428	if (str) {
1429		memcpy(out, str, savelen);
1430		STADJUST(savelen, out);
1431		INTOFF;
1432		ckfree(str);
1433		str = NULL;
1434		INTON;
1435	}
1436	parsebackquote = savepbq;
1437	handler = savehandler;
1438	if (arinest || dblquote)
1439		USTPUTC(CTLBACKQ | CTLQUOTE, out);
1440	else
1441		USTPUTC(CTLBACKQ, out);
1442	if (oldstyle)
1443		goto parsebackq_oldreturn;
1444	else
1445		goto parsebackq_newreturn;
1446}
1447
1448/*
1449 * Parse an arithmetic expansion (indicate start of one and set state)
1450 */
1451parsearith: {
1452
1453	if (++arinest == 1) {
1454		prevsyntax = syntax;
1455		syntax = ARISYNTAX;
1456		USTPUTC(CTLARI, out);
1457		if (dblquote)
1458			USTPUTC('"',out);
1459		else
1460			USTPUTC(' ',out);
1461	} else {
1462		/*
1463		 * we collapse embedded arithmetic expansion to
1464		 * parenthesis, which should be equivalent
1465		 */
1466		USTPUTC('(', out);
1467	}
1468	goto parsearith_return;
1469}
1470
1471} /* end of readtoken */
1472
1473
1474
1475#ifdef mkinit
1476RESET {
1477	tokpushback = 0;
1478	checkkwd = 0;
1479}
1480#endif
1481
1482/*
1483 * Returns true if the text contains nothing to expand (no dollar signs
1484 * or backquotes).
1485 */
1486
1487STATIC int
1488noexpand(char *text)
1489{
1490	char *p;
1491	char c;
1492
1493	p = text;
1494	while ((c = *p++) != '\0') {
1495		if ( c == CTLQUOTEMARK)
1496			continue;
1497		if (c == CTLESC)
1498			p++;
1499		else if (BASESYNTAX[(int)c] == CCTL)
1500			return 0;
1501	}
1502	return 1;
1503}
1504
1505
1506/*
1507 * Return true if the argument is a legal variable name (a letter or
1508 * underscore followed by zero or more letters, underscores, and digits).
1509 */
1510
1511int
1512goodname(char *name)
1513{
1514	char *p;
1515
1516	p = name;
1517	if (! is_name(*p))
1518		return 0;
1519	while (*++p) {
1520		if (! is_in_name(*p))
1521			return 0;
1522	}
1523	return 1;
1524}
1525
1526
1527/*
1528 * Called when an unexpected token is read during the parse.  The argument
1529 * is the token that is expected, or -1 if more than one type of token can
1530 * occur at this point.
1531 */
1532
1533STATIC void
1534synexpect(int token)
1535{
1536	char msg[64];
1537
1538	if (token >= 0) {
1539		fmtstr(msg, 64, "%s unexpected (expecting %s)",
1540			tokname[lasttoken], tokname[token]);
1541	} else {
1542		fmtstr(msg, 64, "%s unexpected", tokname[lasttoken]);
1543	}
1544	synerror(msg);
1545}
1546
1547
1548STATIC void
1549synerror(char *msg)
1550{
1551	if (commandname)
1552		outfmt(&errout, "%s: %d: ", commandname, startlinno);
1553	outfmt(&errout, "Syntax error: %s\n", msg);
1554	error((char *)NULL);
1555}
1556
1557STATIC void
1558setprompt(int which)
1559{
1560	whichprompt = which;
1561
1562#ifndef NO_HISTORY
1563	if (!el)
1564#endif
1565		out2str(getprompt(NULL));
1566}
1567
1568/*
1569 * called by editline -- any expansions to the prompt
1570 *    should be added here.
1571 */
1572char *
1573getprompt(void *unused __unused)
1574{
1575	static char ps[PROMPTLEN];
1576	char *fmt;
1577	int i, j, trim;
1578
1579	/*
1580	 * Select prompt format.
1581	 */
1582	switch (whichprompt) {
1583	case 0:
1584		fmt = "";
1585		break;
1586	case 1:
1587		fmt = ps1val();
1588		break;
1589	case 2:
1590		fmt = ps2val();
1591		break;
1592	default:
1593		return "<internal prompt error>";
1594	}
1595
1596	/*
1597	 * Format prompt string.
1598	 */
1599	for (i = 0; (i < 127) && (*fmt != '\0'); i++, fmt++)
1600		if (*fmt == '\\')
1601			switch (*++fmt) {
1602
1603				/*
1604				 * Hostname.
1605				 *
1606				 * \h specifies just the local hostname,
1607				 * \H specifies fully-qualified hostname.
1608				 */
1609			case 'h':
1610			case 'H':
1611				ps[i] = '\0';
1612				gethostname(&ps[i], PROMPTLEN - i);
1613				/* Skip to end of hostname. */
1614				trim = (*fmt == 'h') ? '.' : '\0';
1615				while ((ps[i+1] != '\0') && (ps[i+1] != trim))
1616					i++;
1617				break;
1618
1619				/*
1620				 * Working directory.
1621				 *
1622				 * \W specifies just the final component,
1623				 * \w specifies the entire path.
1624				 */
1625			case 'W':
1626			case 'w':
1627				ps[i] = '\0';
1628				getcwd(&ps[i], PROMPTLEN - i);
1629				if (*fmt == 'W') {
1630					/* Final path component only. */
1631					trim = 1;
1632					for (j = i; ps[j] != '\0'; j++)
1633					  if (ps[j] == '/')
1634						trim = j + 1;
1635					memmove(&ps[i], &ps[trim],
1636					    j - trim + 1);
1637				}
1638				/* Skip to end of path. */
1639				while (ps[i + 1] != '\0')
1640					i++;
1641				break;
1642
1643				/*
1644				 * Superuser status.
1645				 *
1646				 * '$' for normal users, '#' for root.
1647				 */
1648			case '$':
1649				ps[i] = (geteuid() != 0) ? '$' : '#';
1650				break;
1651
1652				/*
1653				 * A literal \.
1654				 */
1655			case '\\':
1656				ps[i] = '\\';
1657				break;
1658
1659				/*
1660				 * Emit unrecognized formats verbatim.
1661				 */
1662			default:
1663				ps[i++] = '\\';
1664				ps[i] = *fmt;
1665				break;
1666			}
1667		else
1668			ps[i] = *fmt;
1669	ps[i] = '\0';
1670	return (ps);
1671}
1672