source: trunk/src/kash/expand.c@ 2562

Last change on this file since 2562 was 2306, checked in by bird, 17 years ago

kash: better CRLF hack for backtick.
  • Property svn:eol-style set to LF
  • Property svn:keywords set to Id
File size: 33.1 KB
Line 
1/* $NetBSD: expand.c,v 1.71 2005/06/01 15:41:19 lukem Exp $ */
2
3/*-
4 * Copyright (c) 1991, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Kenneth Almquist.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35#if 0
36#ifndef lint
37static char sccsid[] = "@(#)expand.c 8.5 (Berkeley) 5/15/95";
38#else
39__RCSID("$NetBSD: expand.c,v 1.71 2005/06/01 15:41:19 lukem Exp $");
40#endif /* not lint */
41#endif
42
43#include <sys/types.h>
44#include <errno.h>
45#include <stdlib.h>
46#include <stdio.h>
47
48/*
49 * Routines to expand arguments to commands. We have to deal with
50 * backquotes, shell variables, and file metacharacters.
51 */
52
53#include "shell.h"
54#include "main.h"
55#include "nodes.h"
56#include "eval.h"
57#include "expand.h"
58#include "syntax.h"
59#include "parser.h"
60#include "jobs.h"
61#include "options.h"
62#include "var.h"
63#include "input.h"
64#include "output.h"
65#include "memalloc.h"
66#include "error.h"
67#include "mystring.h"
68#include "show.h"
69#include "shinstance.h"
70
71///*
72// * Structure specifying which parts of the string should be searched
73// * for IFS characters.
74// */
75//
76//struct ifsregion {
77// struct ifsregion *next; /* next region in list */
78// int begoff; /* offset of start of region */
79// int endoff; /* offset of end of region */
80// int inquotes; /* search for nul bytes only */
81//};
82//
83//
84//char *expdest; /* output of current string */
85//struct nodelist *argbackq; /* list of back quote expressions */
86//struct ifsregion ifsfirst; /* first struct in list of ifs regions */
87//struct ifsregion *ifslastp; /* last struct in list */
88//struct arglist exparg; /* holds expanded arg list */
89
90STATIC void argstr(shinstance *, char *, int);
91STATIC char *exptilde(shinstance *, char *, int);
92STATIC void expbackq(shinstance *, union node *, int, int);
93STATIC int subevalvar(shinstance *, char *, char *, int, int, int, int);
94STATIC char *evalvar(shinstance *, char *, int);
95STATIC int varisset(shinstance *, char *, int);
96STATIC void varvalue(shinstance *, char *, int, int, int);
97STATIC void recordregion(shinstance *, int, int, int);
98STATIC void removerecordregions(shinstance *, int);
99STATIC void ifsbreakup(shinstance *, char *, struct arglist *);
100STATIC void ifsfree(shinstance *);
101STATIC void expandmeta(shinstance *, struct strlist *, int);
102STATIC void expmeta(shinstance *, char *, char *);
103STATIC void addfname(shinstance *, char *);
104STATIC struct strlist *expsort(struct strlist *);
105STATIC struct strlist *msort(struct strlist *, int);
106STATIC int pmatch(char *, char *, int);
107STATIC char *cvtnum(shinstance *, int, char *);
108
109/*
110 * Expand shell variables and backquotes inside a here document.
111 */
112
113void
114expandhere(shinstance *psh, union node *arg, int fd)
115{
116 psh->herefd = fd;
117 expandarg(psh, arg, (struct arglist *)NULL, 0);
118 xwrite(psh, fd, stackblock(psh), psh->expdest - stackblock(psh));
119}
120
121
122/*
123 * Perform variable substitution and command substitution on an argument,
124 * placing the resulting list of arguments in arglist. If EXP_FULL is true,
125 * perform splitting and file name expansion. When arglist is NULL, perform
126 * here document expansion.
127 */
128
129void
130expandarg(shinstance *psh, union node *arg, struct arglist *arglist, int flag)
131{
132 struct strlist *sp;
133 char *p;
134
135 psh->argbackq = arg->narg.backquote;
136 STARTSTACKSTR(psh, psh->expdest);
137 psh->ifsfirst.next = NULL;
138 psh->ifslastp = NULL;
139 argstr(psh, arg->narg.text, flag);
140 if (arglist == NULL) {
141 return; /* here document expanded */
142 }
143 STPUTC(psh, '\0', psh->expdest);
144 p = grabstackstr(psh, psh->expdest);
145 psh->exparg.lastp = &psh->exparg.list;
146 /*
147 * TODO - EXP_REDIR
148 */
149 if (flag & EXP_FULL) {
150 ifsbreakup(psh, p, &psh->exparg);
151 *psh->exparg.lastp = NULL;
152 psh->exparg.lastp = &psh->exparg.list;
153 expandmeta(psh, psh->exparg.list, flag);
154 } else {
155 if (flag & EXP_REDIR) /*XXX - for now, just remove escapes */
156 rmescapes(psh, p);
157 sp = (struct strlist *)stalloc(psh, sizeof (struct strlist));
158 sp->text = p;
159 *psh->exparg.lastp = sp;
160 psh->exparg.lastp = &sp->next;
161 }
162 ifsfree(psh);
163 *psh->exparg.lastp = NULL;
164 if (psh->exparg.list) {
165 *arglist->lastp = psh->exparg.list;
166 arglist->lastp = psh->exparg.lastp;
167 }
168}
169
170
171
172/*
173 * Perform variable and command substitution.
174 * If EXP_FULL is set, output CTLESC characters to allow for further processing.
175 * Otherwise treat $@ like $* since no splitting will be performed.
176 */
177
178STATIC void
179argstr(shinstance *psh, char *p, int flag)
180{
181 char c;
182 int quotes = flag & (EXP_FULL | EXP_CASE); /* do CTLESC */
183 int firsteq = 1;
184 const char *ifs = NULL;
185 int ifs_split = EXP_IFS_SPLIT;
186
187 if (flag & EXP_IFS_SPLIT)
188 ifs = ifsset(psh) ? ifsval(psh) : " \t\n";
189
190 if (*p == '~' && (flag & (EXP_TILDE | EXP_VARTILDE)))
191 p = exptilde(psh, p, flag);
192 for (;;) {
193 switch (c = *p++) {
194 case '\0':
195 case CTLENDVAR: /* end of expanding yyy in ${xxx-yyy} */
196 return;
197 case CTLQUOTEMARK:
198 /* "$@" syntax adherence hack */
199 if (p[0] == CTLVAR && p[2] == '@' && p[3] == '=')
200 break;
201 if ((flag & EXP_FULL) != 0)
202 STPUTC(psh, c, psh->expdest);
203 ifs_split = 0;
204 break;
205 case CTLQUOTEEND:
206 ifs_split = EXP_IFS_SPLIT;
207 break;
208 case CTLESC:
209 if (quotes)
210 STPUTC(psh, c, psh->expdest);
211 c = *p++;
212 STPUTC(psh, c, psh->expdest);
213 break;
214 case CTLVAR:
215 p = evalvar(psh, p, (flag & ~EXP_IFS_SPLIT) | (flag & ifs_split));
216 break;
217 case CTLBACKQ:
218 case CTLBACKQ|CTLQUOTE:
219 expbackq(psh, psh->argbackq->n, c & CTLQUOTE, flag);
220 psh->argbackq = psh->argbackq->next;
221 break;
222 case CTLENDARI:
223 expari(psh, flag);
224 break;
225 case ':':
226 case '=':
227 /*
228 * sort of a hack - expand tildes in variable
229 * assignments (after the first '=' and after ':'s).
230 */
231 STPUTC(psh, c, psh->expdest);
232 if (flag & EXP_VARTILDE && *p == '~') {
233 if (c == '=') {
234 if (firsteq)
235 firsteq = 0;
236 else
237 break;
238 }
239 p = exptilde(psh, p, flag);
240 }
241 break;
242 default:
243 STPUTC(psh, c, psh->expdest);
244 if (flag & EXP_IFS_SPLIT & ifs_split && strchr(ifs, c) != NULL) {
245 /* We need to get the output split here... */
246 recordregion(psh, (int)(psh->expdest - stackblock(psh) - 1),
247 (int)(psh->expdest - stackblock(psh)), 0);
248 }
249 break;
250 }
251 }
252}
253
254STATIC char *
255exptilde(shinstance *psh, char *p, int flag)
256{
257 char c, *startp = p;
258 const char *home;
259 int quotes = flag & (EXP_FULL | EXP_CASE);
260
261 while ((c = *p) != '\0') {
262 switch(c) {
263 case CTLESC:
264 return (startp);
265 case CTLQUOTEMARK:
266 return (startp);
267 case ':':
268 if (flag & EXP_VARTILDE)
269 goto done;
270 break;
271 case '/':
272 goto done;
273 }
274 p++;
275 }
276done:
277 *p = '\0';
278 if (*(startp+1) == '\0') {
279 if ((home = lookupvar(psh, "HOME")) == NULL)
280 goto lose;
281 } else {
282 if ((home = sh_gethomedir(psh, startp+1)) == NULL)
283 goto lose;
284 }
285 if (*home == '\0')
286 goto lose;
287 *p = c;
288 while ((c = *home++) != '\0') {
289 if (quotes && SQSYNTAX[(int)c] == CCTL)
290 STPUTC(psh, CTLESC, psh->expdest);
291 STPUTC(psh, c, psh->expdest);
292 }
293 return (p);
294lose:
295 *p = c;
296 return (startp);
297}
298
299
300STATIC void
301removerecordregions(shinstance *psh, int endoff)
302{
303 if (psh->ifslastp == NULL)
304 return;
305
306 if (psh->ifsfirst.endoff > endoff) {
307 while (psh->ifsfirst.next != NULL) {
308 struct ifsregion *ifsp;
309 INTOFF;
310 ifsp = psh->ifsfirst.next->next;
311 ckfree(psh, psh->ifsfirst.next);
312 psh->ifsfirst.next = ifsp;
313 INTON;
314 }
315 if (psh->ifsfirst.begoff > endoff)
316 psh->ifslastp = NULL;
317 else {
318 psh->ifslastp = &psh->ifsfirst;
319 psh->ifsfirst.endoff = endoff;
320 }
321 return;
322 }
323
324 psh->ifslastp = &psh->ifsfirst;
325 while (psh->ifslastp->next && psh->ifslastp->next->begoff < endoff)
326 psh->ifslastp=psh->ifslastp->next;
327 while (psh->ifslastp->next != NULL) {
328 struct ifsregion *ifsp;
329 INTOFF;
330 ifsp = psh->ifslastp->next->next;
331 ckfree(psh, psh->ifslastp->next);
332 psh->ifslastp->next = ifsp;
333 INTON;
334 }
335 if (psh->ifslastp->endoff > endoff)
336 psh->ifslastp->endoff = endoff;
337}
338
339
340/*
341 * Expand arithmetic expression. Backup to start of expression,
342 * evaluate, place result in (backed up) result, adjust string position.
343 */
344void
345expari(shinstance *psh, int flag)
346{
347 char *p, *start;
348 int result;
349 int begoff;
350 int quotes = flag & (EXP_FULL | EXP_CASE);
351 int quoted;
352
353 /* ifsfree(); */
354
355 /*
356 * This routine is slightly over-complicated for
357 * efficiency. First we make sure there is
358 * enough space for the result, which may be bigger
359 * than the expression if we add exponentation. Next we
360 * scan backwards looking for the start of arithmetic. If the
361 * next previous character is a CTLESC character, then we
362 * have to rescan starting from the beginning since CTLESC
363 * characters have to be processed left to right.
364 */
365#if INT_MAX / 1000000000 >= 10 || INT_MIN / 1000000000 <= -10
366#error "integers with more than 10 digits are not supported"
367#endif
368 CHECKSTRSPACE(psh, 12 - 2, psh->expdest);
369 USTPUTC(psh, '\0', psh->expdest);
370 start = stackblock(psh);
371 p = psh->expdest - 1;
372 while (*p != CTLARI && p >= start)
373 --p;
374 if (*p != CTLARI)
375 error(psh, "missing CTLARI (shouldn't happen)");
376 if (p > start && *(p-1) == CTLESC)
377 for (p = start; *p != CTLARI; p++)
378 if (*p == CTLESC)
379 p++;
380
381 if (p[1] == '"')
382 quoted=1;
383 else
384 quoted=0;
385 begoff = (int)(p - start);
386 removerecordregions(psh, begoff);
387 if (quotes)
388 rmescapes(psh, p+2);
389 result = arith(psh, p+2);
390 fmtstr(p, 12, "%d", result);
391
392 while (*p++)
393 ;
394
395 if (quoted == 0)
396 recordregion(psh, begoff, (int)(p - 1 - start), 0);
397 result = (int)(psh->expdest - p + 1);
398 STADJUST(psh, -result, psh->expdest);
399}
400
401
402/*
403 * Expand stuff in backwards quotes.
404 */
405
406STATIC void
407expbackq(shinstance *psh, union node *cmd, int quoted, int flag)
408{
409 struct backcmd in;
410 int i;
411 char buf[128];
412 char *p;
413 char *dest = psh->expdest;
414 struct ifsregion saveifs, *savelastp;
415 struct nodelist *saveargbackq;
416 char lastc;
417 int startloc = (int)(dest - stackblock(psh));
418 char const *syntax = quoted? DQSYNTAX : BASESYNTAX;
419 int saveherefd;
420 int quotes = flag & (EXP_FULL | EXP_CASE);
421#ifdef SH_DEAL_WITH_CRLF
422 int pending_cr = 0;
423#endif
424
425 INTOFF;
426 saveifs = psh->ifsfirst;
427 savelastp = psh->ifslastp;
428 saveargbackq = psh->argbackq;
429 saveherefd = psh->herefd;
430 psh->herefd = -1;
431 p = grabstackstr(psh, dest);
432 evalbackcmd(psh, cmd, &in);
433 ungrabstackstr(psh, p, dest);
434 psh->ifsfirst = saveifs;
435 psh->ifslastp = savelastp;
436 psh->argbackq = saveargbackq;
437 psh->herefd = saveherefd;
438
439 p = in.buf;
440 lastc = '\0';
441 for (;;) {
442 if (--in.nleft < 0) {
443 if (in.fd < 0)
444 break;
445 while ((i = shfile_read(&psh->fdtab, in.fd, buf, sizeof buf)) < 0 && errno == EINTR);
446 TRACE((psh, "expbackq: read returns %d\n", i));
447 if (i <= 0)
448 break;
449 p = buf;
450 in.nleft = i - 1;
451 }
452 lastc = *p++;
453#ifdef SH_DEAL_WITH_CRLF
454 if (pending_cr) {
455 pending_cr = 0;
456 if (lastc != '\n') {
457 if (quotes && syntax[(int)'\r'] == CCTL)
458 STPUTC(psh, CTLESC, dest);
459 STPUTC(psh, '\r', dest);
460 }
461 }
462 if (lastc == '\r')
463 pending_cr = '\r';
464 else
465#endif
466 if (lastc != '\0') {
467 if (quotes && syntax[(int)lastc] == CCTL)
468 STPUTC(psh, CTLESC, dest);
469 STPUTC(psh, lastc, dest);
470 }
471 }
472#ifdef SH_DEAL_WITH_CRLF
473 if (pending_cr) {
474 if (quotes && syntax[(int)'\r'] == CCTL)
475 STPUTC(psh, CTLESC, dest);
476 STPUTC(psh, '\r', dest);
477 }
478#endif
479
480 /* Eat all trailing newlines */
481 p = stackblock(psh) + startloc;
482 while (dest > p && dest[-1] == '\n')
483 STUNPUTC(psh, dest);
484
485 if (in.fd >= 0)
486 shfile_close(&psh->fdtab, in.fd);
487 if (in.buf)
488 ckfree(psh, in.buf);
489 if (in.jp)
490 psh->back_exitstatus = waitforjob(psh, in.jp);
491 if (quoted == 0)
492 recordregion(psh, startloc, (int)(dest - stackblock(psh)), 0);
493 TRACE((psh, "evalbackq: size=%d: \"%.*s\"\n",
494 (dest - stackblock(psh)) - startloc,
495 (dest - stackblock(psh)) - startloc,
496 stackblock(psh) + startloc));
497 psh->expdest = dest;
498 INTON;
499}
500
501
502
503STATIC int
504subevalvar(shinstance *psh, char *p, char *str, int strloc, int subtype, int startloc, int varflags)
505{
506 char *startp;
507 char *loc = NULL;
508 char *q;
509 int c = 0;
510 int saveherefd = psh->herefd;
511 struct nodelist *saveargbackq = psh->argbackq;
512 int amount;
513
514 psh->herefd = -1;
515 argstr(psh, p, 0);
516 STACKSTRNUL(psh, psh->expdest);
517 psh->herefd = saveherefd;
518 psh->argbackq = saveargbackq;
519 startp = stackblock(psh) + startloc;
520 if (str == NULL)
521 str = stackblock(psh) + strloc;
522
523 switch (subtype) {
524 case VSASSIGN:
525 setvar(psh, str, startp, 0);
526 amount = (int)(startp - psh->expdest);
527 STADJUST(psh, amount, psh->expdest);
528 varflags &= ~VSNUL;
529 if (c != 0)
530 *loc = c;
531 return 1;
532
533 case VSQUESTION:
534 if (*p != CTLENDVAR) {
535 outfmt(&psh->errout, "%s\n", startp);
536 error(psh, (char *)NULL);
537 }
538 error(psh, "%.*s: parameter %snot set", p - str - 1,
539 str, (varflags & VSNUL) ? "null or "
540 : nullstr);
541 /* NOTREACHED */
542
543 case VSTRIMLEFT:
544 for (loc = startp; loc < str; loc++) {
545 c = *loc;
546 *loc = '\0';
547 if (patmatch(psh, str, startp, varflags & VSQUOTE))
548 goto recordleft;
549 *loc = c;
550 if ((varflags & VSQUOTE) && *loc == CTLESC)
551 loc++;
552 }
553 return 0;
554
555 case VSTRIMLEFTMAX:
556 for (loc = str - 1; loc >= startp;) {
557 c = *loc;
558 *loc = '\0';
559 if (patmatch(psh, str, startp, varflags & VSQUOTE))
560 goto recordleft;
561 *loc = c;
562 loc--;
563 if ((varflags & VSQUOTE) && loc > startp &&
564 *(loc - 1) == CTLESC) {
565 for (q = startp; q < loc; q++)
566 if (*q == CTLESC)
567 q++;
568 if (q > loc)
569 loc--;
570 }
571 }
572 return 0;
573
574 case VSTRIMRIGHT:
575 for (loc = str - 1; loc >= startp;) {
576 if (patmatch(psh, str, loc, varflags & VSQUOTE))
577 goto recordright;
578 loc--;
579 if ((varflags & VSQUOTE) && loc > startp &&
580 *(loc - 1) == CTLESC) {
581 for (q = startp; q < loc; q++)
582 if (*q == CTLESC)
583 q++;
584 if (q > loc)
585 loc--;
586 }
587 }
588 return 0;
589
590 case VSTRIMRIGHTMAX:
591 for (loc = startp; loc < str - 1; loc++) {
592 if (patmatch(psh, str, loc, varflags & VSQUOTE))
593 goto recordright;
594 if ((varflags & VSQUOTE) && *loc == CTLESC)
595 loc++;
596 }
597 return 0;
598
599 default:
600 sh_abort(psh);
601 }
602
603recordleft:
604 *loc = c;
605 amount = (int)(((str - 1) - (loc - startp)) - psh->expdest);
606 STADJUST(psh, amount, psh->expdest);
607 while (loc != str - 1)
608 *startp++ = *loc++;
609 return 1;
610
611recordright:
612 amount = (int)(loc - psh->expdest);
613 STADJUST(psh, amount, psh->expdest);
614 STPUTC(psh, '\0', psh->expdest);
615 STADJUST(psh, -1, psh->expdest);
616 return 1;
617}
618
619
620/*
621 * Expand a variable, and return a pointer to the next character in the
622 * input string.
623 */
624
625STATIC char *
626evalvar(shinstance *psh, char *p, int flag)
627{
628 int subtype;
629 int varflags;
630 char *var;
631 char *val;
632 int patloc;
633 int c;
634 int set;
635 int special;
636 int startloc;
637 int varlen;
638 int apply_ifs;
639 int quotes = flag & (EXP_FULL | EXP_CASE);
640
641 varflags = (unsigned char)*p++;
642 subtype = varflags & VSTYPE;
643 var = p;
644 special = !is_name(*p);
645 p = strchr(p, '=') + 1;
646
647again: /* jump here after setting a variable with ${var=text} */
648 if (special) {
649 set = varisset(psh, var, varflags & VSNUL);
650 val = NULL;
651 } else {
652 val = lookupvar(psh, var);
653 if (val == NULL || ((varflags & VSNUL) && val[0] == '\0')) {
654 val = NULL;
655 set = 0;
656 } else
657 set = 1;
658 }
659
660 varlen = 0;
661 startloc = (int)(psh->expdest - stackblock(psh));
662
663 if (!set && uflag(psh)) {
664 switch (subtype) {
665 case VSNORMAL:
666 case VSTRIMLEFT:
667 case VSTRIMLEFTMAX:
668 case VSTRIMRIGHT:
669 case VSTRIMRIGHTMAX:
670 case VSLENGTH:
671 error(psh, "%.*s: parameter not set", p - var - 1, var);
672 /* NOTREACHED */
673 }
674 }
675
676 if (set && subtype != VSPLUS) {
677 /* insert the value of the variable */
678 if (special) {
679 varvalue(psh, var, varflags & VSQUOTE, subtype, flag);
680 if (subtype == VSLENGTH) {
681 varlen = (int)(psh->expdest - stackblock(psh) - startloc);
682 STADJUST(psh, -varlen, psh->expdest);
683 }
684 } else {
685 char const *syntax = (varflags & VSQUOTE) ? DQSYNTAX
686 : BASESYNTAX;
687
688 if (subtype == VSLENGTH) {
689 for (;*val; val++)
690 varlen++;
691 } else {
692 while (*val) {
693 if (quotes && syntax[(int)*val] == CCTL)
694 STPUTC(psh, CTLESC, psh->expdest);
695 STPUTC(psh, *val++, psh->expdest);
696 }
697
698 }
699 }
700 }
701
702
703 apply_ifs = ((varflags & VSQUOTE) == 0 ||
704 (*var == '@' && psh->shellparam.nparam != 1));
705
706 switch (subtype) {
707 case VSLENGTH:
708 psh->expdest = cvtnum(psh, varlen, psh->expdest);
709 break;
710
711 case VSNORMAL:
712 break;
713
714 case VSPLUS:
715 set = !set;
716 /* FALLTHROUGH */
717 case VSMINUS:
718 if (!set) {
719 argstr(psh, p, flag | (apply_ifs ? EXP_IFS_SPLIT : 0));
720 /*
721 * ${x-a b c} doesn't get split, but removing the
722 * 'apply_ifs = 0' apparantly breaks ${1+"$@"}..
723 * ${x-'a b' c} should generate 2 args.
724 */
725 /* We should have marked stuff already */
726 apply_ifs = 0;
727 }
728 break;
729
730 case VSTRIMLEFT:
731 case VSTRIMLEFTMAX:
732 case VSTRIMRIGHT:
733 case VSTRIMRIGHTMAX:
734 if (!set)
735 break;
736 /*
737 * Terminate the string and start recording the pattern
738 * right after it
739 */
740 STPUTC(psh, '\0', psh->expdest);
741 patloc = (int)(psh->expdest - stackblock(psh));
742 if (subevalvar(psh, p, NULL, patloc, subtype,
743 startloc, varflags) == 0) {
744 int amount = (int)(psh->expdest - stackblock(psh) - patloc) + 1;
745 STADJUST(psh, -amount, psh->expdest);
746 }
747 /* Remove any recorded regions beyond start of variable */
748 removerecordregions(psh, startloc);
749 apply_ifs = 1;
750 break;
751
752 case VSASSIGN:
753 case VSQUESTION:
754 if (set)
755 break;
756 if (subevalvar(psh, p, var, 0, subtype, startloc, varflags)) {
757 varflags &= ~VSNUL;
758 /*
759 * Remove any recorded regions beyond
760 * start of variable
761 */
762 removerecordregions(psh, startloc);
763 goto again;
764 }
765 apply_ifs = 0;
766 break;
767
768 default:
769 sh_abort(psh);
770 }
771
772 if (apply_ifs)
773 recordregion(psh, startloc, (int)(psh->expdest - stackblock(psh)),
774 varflags & VSQUOTE);
775
776 if (subtype != VSNORMAL) { /* skip to end of alternative */
777 int nesting = 1;
778 for (;;) {
779 if ((c = *p++) == CTLESC)
780 p++;
781 else if (c == CTLBACKQ || c == (CTLBACKQ|CTLQUOTE)) {
782 if (set)
783 psh->argbackq = psh->argbackq->next;
784 } else if (c == CTLVAR) {
785 if ((*p++ & VSTYPE) != VSNORMAL)
786 nesting++;
787 } else if (c == CTLENDVAR) {
788 if (--nesting == 0)
789 break;
790 }
791 }
792 }
793 return p;
794}
795
796
797
798/*
799 * Test whether a specialized variable is set.
800 */
801
802STATIC int
803varisset(shinstance *psh, char *name, int nulok)
804{
805 if (*name == '!')
806 return psh->backgndpid != -1;
807 else if (*name == '@' || *name == '*') {
808 if (*psh->shellparam.p == NULL)
809 return 0;
810
811 if (nulok) {
812 char **av;
813
814 for (av = psh->shellparam.p; *av; av++)
815 if (**av != '\0')
816 return 1;
817 return 0;
818 }
819 } else if (is_digit(*name)) {
820 char *ap;
821 int num = atoi(name);
822
823 if (num > psh->shellparam.nparam)
824 return 0;
825
826 if (num == 0)
827 ap = psh->arg0;
828 else
829 ap = psh->shellparam.p[num - 1];
830
831 if (nulok && (ap == NULL || *ap == '\0'))
832 return 0;
833 }
834 return 1;
835}
836
837
838
839/*
840 * Add the value of a specialized variable to the stack string.
841 */
842
843STATIC void
844varvalue(shinstance *psh, char *name, int quoted, int subtype, int flag)
845{
846 int num;
847 char *p;
848 int i;
849 char sep;
850 char **ap;
851 char const *syntax;
852
853#define STRTODEST(p) \
854 do {\
855 if (flag & (EXP_FULL | EXP_CASE) && subtype != VSLENGTH) { \
856 syntax = quoted? DQSYNTAX : BASESYNTAX; \
857 while (*p) { \
858 if (syntax[(int)*p] == CCTL) \
859 STPUTC(psh, CTLESC, psh->expdest); \
860 STPUTC(psh, *p++, psh->expdest); \
861 } \
862 } else \
863 while (*p) \
864 STPUTC(psh, *p++, psh->expdest); \
865 } while (0)
866
867
868 switch (*name) {
869 case '$':
870 num = psh->rootpid;
871 goto numvar;
872 case '?':
873 num = psh->exitstatus;
874 goto numvar;
875 case '#':
876 num = psh->shellparam.nparam;
877 goto numvar;
878 case '!':
879 num = psh->backgndpid;
880numvar:
881 psh->expdest = cvtnum(psh, num, psh->expdest);
882 break;
883 case '-':
884 for (i = 0; psh->optlist[i].name; i++) {
885 if (psh->optlist[i].val)
886 STPUTC(psh, psh->optlist[i].letter, psh->expdest);
887 }
888 break;
889 case '@':
890 if (flag & EXP_FULL && quoted) {
891 for (ap = psh->shellparam.p ; (p = *ap++) != NULL ; ) {
892 STRTODEST(p);
893 if (*ap)
894 STPUTC(psh, '\0', psh->expdest);
895 }
896 break;
897 }
898 /* fall through */
899 case '*':
900 if (ifsset(psh) != 0)
901 sep = ifsval(psh)[0];
902 else
903 sep = ' ';
904 for (ap = psh->shellparam.p ; (p = *ap++) != NULL ; ) {
905 STRTODEST(p);
906 if (*ap && sep)
907 STPUTC(psh, sep, psh->expdest);
908 }
909 break;
910 case '0':
911 p = psh->arg0;
912 STRTODEST(p);
913 break;
914 default:
915 if (is_digit(*name)) {
916 num = atoi(name);
917 if (num > 0 && num <= psh->shellparam.nparam) {
918 p = psh->shellparam.p[num - 1];
919 STRTODEST(p);
920 }
921 }
922 break;
923 }
924}
925
926
927
928/*
929 * Record the fact that we have to scan this region of the
930 * string for IFS characters.
931 */
932
933STATIC void
934recordregion(shinstance *psh, int start, int end, int inquotes)
935{
936 struct ifsregion *ifsp;
937
938 if (psh->ifslastp == NULL) {
939 ifsp = &psh->ifsfirst;
940 } else {
941 if (psh->ifslastp->endoff == start
942 && psh->ifslastp->inquotes == inquotes) {
943 /* extend previous area */
944 psh->ifslastp->endoff = end;
945 return;
946 }
947 ifsp = (struct ifsregion *)ckmalloc(psh, sizeof (struct ifsregion));
948 psh->ifslastp->next = ifsp;
949 }
950 psh->ifslastp = ifsp;
951 psh->ifslastp->next = NULL;
952 psh->ifslastp->begoff = start;
953 psh->ifslastp->endoff = end;
954 psh->ifslastp->inquotes = inquotes;
955}
956
957
958
959/*
960 * Break the argument string into pieces based upon IFS and add the
961 * strings to the argument list. The regions of the string to be
962 * searched for IFS characters have been stored by recordregion.
963 */
964STATIC void
965ifsbreakup(shinstance *psh, char *string, struct arglist *arglist)
966{
967 struct ifsregion *ifsp;
968 struct strlist *sp;
969 char *start;
970 char *p;
971 char *q;
972 const char *ifs;
973 const char *ifsspc;
974 int inquotes;
975
976 start = string;
977 ifsspc = NULL;
978 inquotes = 0;
979
980 if (psh->ifslastp == NULL) {
981 /* Return entire argument, IFS doesn't apply to any of it */
982 sp = (struct strlist *)stalloc(psh, sizeof *sp);
983 sp->text = start;
984 *arglist->lastp = sp;
985 arglist->lastp = &sp->next;
986 return;
987 }
988
989 ifs = ifsset(psh) ? ifsval(psh) : " \t\n";
990
991 for (ifsp = &psh->ifsfirst; ifsp != NULL; ifsp = ifsp->next) {
992 p = string + ifsp->begoff;
993 inquotes = ifsp->inquotes;
994 ifsspc = NULL;
995 while (p < string + ifsp->endoff) {
996 q = p;
997 if (*p == CTLESC)
998 p++;
999 if (inquotes) {
1000 /* Only NULs (probably from "$@") end args */
1001 if (*p != 0) {
1002 p++;
1003 continue;
1004 }
1005 } else {
1006 if (!strchr(ifs, *p)) {
1007 p++;
1008 continue;
1009 }
1010 ifsspc = strchr(" \t\n", *p);
1011
1012 /* Ignore IFS whitespace at start */
1013 if (q == start && ifsspc != NULL) {
1014 p++;
1015 start = p;
1016 continue;
1017 }
1018 }
1019
1020 /* Save this argument... */
1021 *q = '\0';
1022 sp = (struct strlist *)stalloc(psh, sizeof *sp);
1023 sp->text = start;
1024 *arglist->lastp = sp;
1025 arglist->lastp = &sp->next;
1026 p++;
1027
1028 if (ifsspc != NULL) {
1029 /* Ignore further trailing IFS whitespace */
1030 for (; p < string + ifsp->endoff; p++) {
1031 q = p;
1032 if (*p == CTLESC)
1033 p++;
1034 if (strchr(ifs, *p) == NULL) {
1035 p = q;
1036 break;
1037 }
1038 if (strchr(" \t\n", *p) == NULL) {
1039 p++;
1040 break;
1041 }
1042 }
1043 }
1044 start = p;
1045 }
1046 }
1047
1048 /*
1049 * Save anything left as an argument.
1050 * Traditionally we have treated 'IFS=':'; set -- x$IFS' as
1051 * generating 2 arguments, the second of which is empty.
1052 * Some recent clarification of the Posix spec say that it
1053 * should only generate one....
1054 */
1055 if (*start /* || (!ifsspc && start > string) */) {
1056 sp = (struct strlist *)stalloc(psh, sizeof *sp);
1057 sp->text = start;
1058 *arglist->lastp = sp;
1059 arglist->lastp = &sp->next;
1060 }
1061}
1062
1063STATIC void
1064ifsfree(shinstance *psh)
1065{
1066 while (psh->ifsfirst.next != NULL) {
1067 struct ifsregion *ifsp;
1068 INTOFF;
1069 ifsp = psh->ifsfirst.next->next;
1070 ckfree(psh, psh->ifsfirst.next);
1071 psh->ifsfirst.next = ifsp;
1072 INTON;
1073 }
1074 psh->ifslastp = NULL;
1075 psh->ifsfirst.next = NULL;
1076}
1077
1078
1079
1080/*
1081 * Expand shell metacharacters. At this point, the only control characters
1082 * should be escapes. The results are stored in the list psh->exparg.
1083 */
1084
1085//char *expdir;
1086
1087
1088STATIC void
1089expandmeta(shinstance *psh, struct strlist *str, int flag)
1090{
1091 char *p;
1092 struct strlist **savelastp;
1093 struct strlist *sp;
1094 char c;
1095 /* TODO - EXP_REDIR */
1096
1097 while (str) {
1098 if (fflag(psh))
1099 goto nometa;
1100 p = str->text;
1101 for (;;) { /* fast check for meta chars */
1102 if ((c = *p++) == '\0')
1103 goto nometa;
1104 if (c == '*' || c == '?' || c == '[' || c == '!')
1105 break;
1106 }
1107 savelastp = psh->exparg.lastp;
1108 INTOFF;
1109 if (psh->expdir == NULL) {
1110 size_t i = strlen(str->text);
1111 psh->expdir = ckmalloc(psh, i < 2048 ? 2048 : i); /* XXX */
1112 }
1113
1114 expmeta(psh, psh->expdir, str->text);
1115 ckfree(psh, psh->expdir);
1116 psh->expdir = NULL;
1117 INTON;
1118 if (psh->exparg.lastp == savelastp) {
1119 /*
1120 * no matches
1121 */
1122nometa:
1123 *psh->exparg.lastp = str;
1124 rmescapes(psh, str->text);
1125 psh->exparg.lastp = &str->next;
1126 } else {
1127 *psh->exparg.lastp = NULL;
1128 *savelastp = sp = expsort(*savelastp);
1129 while (sp->next != NULL)
1130 sp = sp->next;
1131 psh->exparg.lastp = &sp->next;
1132 }
1133 str = str->next;
1134 }
1135}
1136
1137
1138/*
1139 * Do metacharacter (i.e. *, ?, [...]) expansion.
1140 */
1141
1142STATIC void
1143expmeta(shinstance *psh, char *enddir, char *name)
1144{
1145 char *p;
1146 const char *cp;
1147 char *q;
1148 char *start;
1149 char *endname;
1150 int metaflag;
1151 struct stat statb;
1152 shdir *dirp;
1153 shdirent *dp;
1154 int atend;
1155 int matchdot;
1156
1157 metaflag = 0;
1158 start = name;
1159 for (p = name ; ; p++) {
1160 if (*p == '*' || *p == '?')
1161 metaflag = 1;
1162 else if (*p == '[') {
1163 q = p + 1;
1164 if (*q == '!')
1165 q++;
1166 for (;;) {
1167 while (*q == CTLQUOTEMARK)
1168 q++;
1169 if (*q == CTLESC)
1170 q++;
1171 if (*q == '/' || *q == '\0')
1172 break;
1173 if (*++q == ']') {
1174 metaflag = 1;
1175 break;
1176 }
1177 }
1178 } else if (*p == '!' && p[1] == '!' && (p == name || p[-1] == '/')) {
1179 metaflag = 1;
1180 } else if (*p == '\0')
1181 break;
1182 else if (*p == CTLQUOTEMARK)
1183 continue;
1184 else if (*p == CTLESC)
1185 p++;
1186 if (*p == '/') {
1187 if (metaflag)
1188 break;
1189 start = p + 1;
1190 }
1191 }
1192 if (metaflag == 0) { /* we've reached the end of the file name */
1193 if (enddir != psh->expdir)
1194 metaflag++;
1195 for (p = name ; ; p++) {
1196 if (*p == CTLQUOTEMARK)
1197 continue;
1198 if (*p == CTLESC)
1199 p++;
1200 *enddir++ = *p;
1201 if (*p == '\0')
1202 break;
1203 }
1204 if (metaflag == 0 || shfile_lstat(&psh->fdtab, psh->expdir, &statb) >= 0)
1205 addfname(psh, psh->expdir);
1206 return;
1207 }
1208 endname = p;
1209 if (start != name) {
1210 p = name;
1211 while (p < start) {
1212 while (*p == CTLQUOTEMARK)
1213 p++;
1214 if (*p == CTLESC)
1215 p++;
1216 *enddir++ = *p++;
1217 }
1218 }
1219 if (enddir == psh->expdir) {
1220 cp = ".";
1221 } else if (enddir == psh->expdir + 1 && *psh->expdir == '/') {
1222 cp = "/";
1223 } else {
1224 cp = psh->expdir;
1225 enddir[-1] = '\0';
1226 }
1227 if ((dirp = shfile_opendir(&psh->fdtab, cp)) == NULL)
1228 return;
1229 if (enddir != psh->expdir)
1230 enddir[-1] = '/';
1231 if (*endname == 0) {
1232 atend = 1;
1233 } else {
1234 atend = 0;
1235 *endname++ = '\0';
1236 }
1237 matchdot = 0;
1238 p = start;
1239 while (*p == CTLQUOTEMARK)
1240 p++;
1241 if (*p == CTLESC)
1242 p++;
1243 if (*p == '.')
1244 matchdot++;
1245 while (! int_pending() && (dp = shfile_readdir(dirp)) != NULL) {
1246 if (dp->name[0] == '.' && ! matchdot)
1247 continue;
1248 if (patmatch(psh, start, dp->name, 0)) {
1249 if (atend) {
1250 scopy(dp->name, enddir);
1251 addfname(psh, psh->expdir);
1252 } else {
1253 for (p = enddir, cp = dp->name;
1254 (*p++ = *cp++) != '\0';)
1255 continue;
1256 p[-1] = '/';
1257 expmeta(psh, p, endname);
1258 }
1259 }
1260 }
1261 shfile_closedir(dirp);
1262 if (! atend)
1263 endname[-1] = '/';
1264}
1265
1266
1267/*
1268 * Add a file name to the list.
1269 */
1270
1271STATIC void
1272addfname(shinstance *psh, char *name)
1273{
1274 char *p;
1275 struct strlist *sp;
1276
1277 p = stalloc(psh, strlen(name) + 1);
1278 scopy(name, p);
1279 sp = (struct strlist *)stalloc(psh, sizeof *sp);
1280 sp->text = p;
1281 *psh->exparg.lastp = sp;
1282 psh->exparg.lastp = &sp->next;
1283}
1284
1285
1286/*
1287 * Sort the results of file name expansion. It calculates the number of
1288 * strings to sort and then calls msort (short for merge sort) to do the
1289 * work.
1290 */
1291
1292STATIC struct strlist *
1293expsort(struct strlist *str)
1294{
1295 int len;
1296 struct strlist *sp;
1297
1298 len = 0;
1299 for (sp = str ; sp ; sp = sp->next)
1300 len++;
1301 return msort(str, len);
1302}
1303
1304
1305STATIC struct strlist *
1306msort(struct strlist *list, int len)
1307{
1308 struct strlist *p, *q = NULL;
1309 struct strlist **lpp;
1310 int half;
1311 int n;
1312
1313 if (len <= 1)
1314 return list;
1315 half = len >> 1;
1316 p = list;
1317 for (n = half ; --n >= 0 ; ) {
1318 q = p;
1319 p = p->next;
1320 }
1321 q->next = NULL; /* terminate first half of list */
1322 q = msort(list, half); /* sort first half of list */
1323 p = msort(p, len - half); /* sort second half */
1324 lpp = &list;
1325 for (;;) {
1326 if (strcmp(p->text, q->text) < 0) {
1327 *lpp = p;
1328 lpp = &p->next;
1329 if ((p = *lpp) == NULL) {
1330 *lpp = q;
1331 break;
1332 }
1333 } else {
1334 *lpp = q;
1335 lpp = &q->next;
1336 if ((q = *lpp) == NULL) {
1337 *lpp = p;
1338 break;
1339 }
1340 }
1341 }
1342 return list;
1343}
1344
1345
1346
1347/*
1348 * Returns true if the pattern matches the string.
1349 */
1350
1351int
1352patmatch(shinstance *psh, char *pattern, char *string, int squoted)
1353{
1354#ifdef notdef
1355 if (pattern[0] == '!' && pattern[1] == '!')
1356 return 1 - pmatch(pattern + 2, string);
1357 else
1358#endif
1359 return pmatch(pattern, string, squoted);
1360}
1361
1362
1363STATIC int
1364pmatch(char *pattern, char *string, int squoted)
1365{
1366 char *p, *q;
1367 char c;
1368
1369 p = pattern;
1370 q = string;
1371 for (;;) {
1372 switch (c = *p++) {
1373 case '\0':
1374 goto breakloop;
1375 case CTLESC:
1376 if (squoted && *q == CTLESC)
1377 q++;
1378 if (*q++ != *p++)
1379 return 0;
1380 break;
1381 case CTLQUOTEMARK:
1382 continue;
1383 case '?':
1384 if (squoted && *q == CTLESC)
1385 q++;
1386 if (*q++ == '\0')
1387 return 0;
1388 break;
1389 case '*':
1390 c = *p;
1391 while (c == CTLQUOTEMARK || c == '*')
1392 c = *++p;
1393 if (c != CTLESC && c != CTLQUOTEMARK &&
1394 c != '?' && c != '*' && c != '[') {
1395 while (*q != c) {
1396 if (squoted && *q == CTLESC &&
1397 q[1] == c)
1398 break;
1399 if (*q == '\0')
1400 return 0;
1401 if (squoted && *q == CTLESC)
1402 q++;
1403 q++;
1404 }
1405 }
1406 do {
1407 if (pmatch(p, q, squoted))
1408 return 1;
1409 if (squoted && *q == CTLESC)
1410 q++;
1411 } while (*q++ != '\0');
1412 return 0;
1413 case '[': {
1414 char *endp;
1415 int invert, found;
1416 char chr;
1417
1418 endp = p;
1419 if (*endp == '!')
1420 endp++;
1421 for (;;) {
1422 while (*endp == CTLQUOTEMARK)
1423 endp++;
1424 if (*endp == '\0')
1425 goto dft; /* no matching ] */
1426 if (*endp == CTLESC)
1427 endp++;
1428 if (*++endp == ']')
1429 break;
1430 }
1431 invert = 0;
1432 if (*p == '!') {
1433 invert++;
1434 p++;
1435 }
1436 found = 0;
1437 chr = *q++;
1438 if (squoted && chr == CTLESC)
1439 chr = *q++;
1440 if (chr == '\0')
1441 return 0;
1442 c = *p++;
1443 do {
1444 if (c == CTLQUOTEMARK)
1445 continue;
1446 if (c == CTLESC)
1447 c = *p++;
1448 if (*p == '-' && p[1] != ']') {
1449 p++;
1450 while (*p == CTLQUOTEMARK)
1451 p++;
1452 if (*p == CTLESC)
1453 p++;
1454 if (chr >= c && chr <= *p)
1455 found = 1;
1456 p++;
1457 } else {
1458 if (chr == c)
1459 found = 1;
1460 }
1461 } while ((c = *p++) != ']');
1462 if (found == invert)
1463 return 0;
1464 break;
1465 }
1466dft: default:
1467 if (squoted && *q == CTLESC)
1468 q++;
1469 if (*q++ != c)
1470 return 0;
1471 break;
1472 }
1473 }
1474breakloop:
1475 if (*q != '\0')
1476 return 0;
1477 return 1;
1478}
1479
1480
1481
1482/*
1483 * Remove any CTLESC characters from a string.
1484 */
1485
1486void
1487rmescapes(shinstance *psh, char *str)
1488{
1489 char *p, *q;
1490
1491 p = str;
1492 while (*p != CTLESC && *p != CTLQUOTEMARK) {
1493 if (*p++ == '\0')
1494 return;
1495 }
1496 q = p;
1497 while (*p) {
1498 if (*p == CTLQUOTEMARK) {
1499 p++;
1500 continue;
1501 }
1502 if (*p == CTLESC)
1503 p++;
1504 *q++ = *p++;
1505 }
1506 *q = '\0';
1507}
1508
1509
1510
1511/*
1512 * See if a pattern matches in a case statement.
1513 */
1514
1515int
1516casematch(shinstance *psh, union node *pattern, char *val)
1517{
1518 struct stackmark smark;
1519 int result;
1520 char *p;
1521
1522 setstackmark(psh, &smark);
1523 psh->argbackq = pattern->narg.backquote;
1524 STARTSTACKSTR(psh, psh->expdest);
1525 psh->ifslastp = NULL;
1526 argstr(psh, pattern->narg.text, EXP_TILDE | EXP_CASE);
1527 STPUTC(psh, '\0', psh->expdest);
1528 p = grabstackstr(psh, psh->expdest);
1529 result = patmatch(psh, p, val, 0);
1530 popstackmark(psh, &smark);
1531 return result;
1532}
1533
1534/*
1535 * Our own itoa().
1536 */
1537
1538STATIC char *
1539cvtnum(shinstance *psh, int num, char *buf)
1540{
1541 char temp[32];
1542 int neg = num < 0;
1543 char *p = temp + 31;
1544
1545 temp[31] = '\0';
1546
1547 do {
1548 *--p = num % 10 + '0';
1549 } while ((num /= 10) != 0);
1550
1551 if (neg)
1552 *--p = '-';
1553
1554 while (*p)
1555 STPUTC(psh, *p++, buf);
1556 return buf;
1557}
1558
1559/*
1560 * Do most of the work for wordexp(3).
1561 */
1562
1563int
1564wordexpcmd(shinstance *psh, int argc, char **argv)
1565{
1566 size_t len;
1567 int i;
1568
1569 out1fmt(psh, "%d", argc - 1);
1570 out1c(psh, '\0');
1571 for (i = 1, len = 0; i < argc; i++)
1572 len += strlen(argv[i]);
1573 out1fmt(psh, "%zd", len);
1574 out1c(psh, '\0');
1575 for (i = 1; i < argc; i++) {
1576 out1str(psh, argv[i]);
1577 out1c(psh, '\0');
1578 }
1579 return (0);
1580}
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