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source: kBuild/trunk/src/kmk/kmkbuiltin/test.c@ 1291

Last change on this file since 1291 was 1291, checked in by bird, 17 years ago

NetBSD src/bin/test/test.c, revision 1.33.
File size: 16.5 KB
Line 
1/* $NetBSD: test.c,v 1.33 2007/06/24 18:54:58 christos Exp $ */
2
3/*
4 * test(1); version 7-like -- author Erik Baalbergen
5 * modified by Eric Gisin to be used as built-in.
6 * modified by Arnold Robbins to add SVR3 compatibility
7 * (-x -c -b -p -u -g -k) plus Korn's -L -nt -ot -ef and new -S (socket).
8 * modified by J.T. Conklin for NetBSD.
9 *
10 * This program is in the Public Domain.
11 */
12
13#include <sys/cdefs.h>
14#ifndef lint
15__RCSID("$NetBSD: test.c,v 1.33 2007/06/24 18:54:58 christos Exp $");
16#endif
17
18#include <sys/stat.h>
19#include <sys/types.h>
20
21#include <ctype.h>
22#include <err.h>
23#include <errno.h>
24#include <limits.h>
25#include <stdio.h>
26#include <stdlib.h>
27#include <string.h>
28#include <unistd.h>
29#include <stdarg.h>
30
31/* test(1) accepts the following grammar:
32 oexpr ::= aexpr | aexpr "-o" oexpr ;
33 aexpr ::= nexpr | nexpr "-a" aexpr ;
34 nexpr ::= primary | "!" primary
35 primary ::= unary-operator operand
36 | operand binary-operator operand
37 | operand
38 | "(" oexpr ")"
39 ;
40 unary-operator ::= "-r"|"-w"|"-x"|"-f"|"-d"|"-c"|"-b"|"-p"|
41 "-u"|"-g"|"-k"|"-s"|"-t"|"-z"|"-n"|"-o"|"-O"|"-G"|"-L"|"-S";
42
43 binary-operator ::= "="|"!="|"-eq"|"-ne"|"-ge"|"-gt"|"-le"|"-lt"|
44 "-nt"|"-ot"|"-ef";
45 operand ::= <any legal UNIX file name>
46*/
47
48enum token {
49 EOI,
50 FILRD,
51 FILWR,
52 FILEX,
53 FILEXIST,
54 FILREG,
55 FILDIR,
56 FILCDEV,
57 FILBDEV,
58 FILFIFO,
59 FILSOCK,
60 FILSYM,
61 FILGZ,
62 FILTT,
63 FILSUID,
64 FILSGID,
65 FILSTCK,
66 FILNT,
67 FILOT,
68 FILEQ,
69 FILUID,
70 FILGID,
71 STREZ,
72 STRNZ,
73 STREQ,
74 STRNE,
75 STRLT,
76 STRGT,
77 INTEQ,
78 INTNE,
79 INTGE,
80 INTGT,
81 INTLE,
82 INTLT,
83 UNOT,
84 BAND,
85 BOR,
86 LPAREN,
87 RPAREN,
88 OPERAND
89};
90
91enum token_types {
92 UNOP,
93 BINOP,
94 BUNOP,
95 BBINOP,
96 PAREN
97};
98
99struct t_op {
100 const char *op_text;
101 short op_num, op_type;
102};
103
104static const struct t_op cop[] = {
105 {"!", UNOT, BUNOP},
106 {"(", LPAREN, PAREN},
107 {")", RPAREN, PAREN},
108 {"<", STRLT, BINOP},
109 {"=", STREQ, BINOP},
110 {">", STRGT, BINOP},
111};
112
113static const struct t_op cop2[] = {
114 {"!=", STRNE, BINOP},
115};
116
117static const struct t_op mop3[] = {
118 {"ef", FILEQ, BINOP},
119 {"eq", INTEQ, BINOP},
120 {"ge", INTGE, BINOP},
121 {"gt", INTGT, BINOP},
122 {"le", INTLE, BINOP},
123 {"lt", INTLT, BINOP},
124 {"ne", INTNE, BINOP},
125 {"nt", FILNT, BINOP},
126 {"ot", FILOT, BINOP},
127};
128
129static const struct t_op mop2[] = {
130 {"G", FILGID, UNOP},
131 {"L", FILSYM, UNOP},
132 {"O", FILUID, UNOP},
133 {"S", FILSOCK,UNOP},
134 {"a", BAND, BBINOP},
135 {"b", FILBDEV,UNOP},
136 {"c", FILCDEV,UNOP},
137 {"d", FILDIR, UNOP},
138 {"e", FILEXIST,UNOP},
139 {"f", FILREG, UNOP},
140 {"g", FILSGID,UNOP},
141 {"h", FILSYM, UNOP}, /* for backwards compat */
142 {"k", FILSTCK,UNOP},
143 {"n", STRNZ, UNOP},
144 {"o", BOR, BBINOP},
145 {"p", FILFIFO,UNOP},
146 {"r", FILRD, UNOP},
147 {"s", FILGZ, UNOP},
148 {"t", FILTT, UNOP},
149 {"u", FILSUID,UNOP},
150 {"w", FILWR, UNOP},
151 {"x", FILEX, UNOP},
152 {"z", STREZ, UNOP},
153};
154
155static char **t_wp;
156static struct t_op const *t_wp_op;
157
158static void syntax(const char *, const char *);
159static int oexpr(enum token);
160static int aexpr(enum token);
161static int nexpr(enum token);
162static int primary(enum token);
163static int binop(void);
164static int test_access(struct stat *, mode_t);
165static int filstat(char *, enum token);
166static enum token t_lex(char *);
167static int isoperand(void);
168static int getn(const char *);
169static int newerf(const char *, const char *);
170static int olderf(const char *, const char *);
171static int equalf(const char *, const char *);
172
173#if defined(SHELL)
174extern void error(const char *, ...) __attribute__((__noreturn__));
175extern void *ckmalloc(size_t);
176#else
177static void error(const char *, ...) __attribute__((__noreturn__));
178
179static void
180error(const char *msg, ...)
181{
182 va_list ap;
183
184 va_start(ap, msg);
185 verrx(2, msg, ap);
186 /*NOTREACHED*/
187 va_end(ap);
188}
189
190static void *ckmalloc(size_t);
191static void *
192ckmalloc(size_t nbytes)
193{
194 void *p = malloc(nbytes);
195
196 if (!p)
197 error("Not enough memory!");
198 return p;
199}
200#endif
201
202#ifdef SHELL
203int testcmd(int, char **);
204
205int
206testcmd(int argc, char **argv)
207#else
208int main(int, char *[]);
209
210int
211main(int argc, char *argv[])
212#endif
213{
214 int res;
215 const char *argv0;
216
217#ifdef SHELL
218 argv0 = argv[0];
219#else
220 setprogname(argv[0]);
221 argv0 = getprogname();
222#endif
223 if (strcmp(argv0, "[") == 0) {
224 if (strcmp(argv[--argc], "]"))
225 error("missing ]");
226 argv[argc] = NULL;
227 }
228
229 if (argc < 2)
230 return 1;
231
232 t_wp = &argv[1];
233 res = !oexpr(t_lex(*t_wp));
234
235 if (*t_wp != NULL && *++t_wp != NULL)
236 syntax(*t_wp, "unexpected operator");
237
238 return res;
239}
240
241static void
242syntax(const char *op, const char *msg)
243{
244
245 if (op && *op)
246 error("%s: %s", op, msg);
247 else
248 error("%s", msg);
249}
250
251static int
252oexpr(enum token n)
253{
254 int res;
255
256 res = aexpr(n);
257 if (*t_wp == NULL)
258 return res;
259 if (t_lex(*++t_wp) == BOR)
260 return oexpr(t_lex(*++t_wp)) || res;
261 t_wp--;
262 return res;
263}
264
265static int
266aexpr(enum token n)
267{
268 int res;
269
270 res = nexpr(n);
271 if (*t_wp == NULL)
272 return res;
273 if (t_lex(*++t_wp) == BAND)
274 return aexpr(t_lex(*++t_wp)) && res;
275 t_wp--;
276 return res;
277}
278
279static int
280nexpr(enum token n)
281{
282
283 if (n == UNOT)
284 return !nexpr(t_lex(*++t_wp));
285 return primary(n);
286}
287
288static int
289primary(enum token n)
290{
291 enum token nn;
292 int res;
293
294 if (n == EOI)
295 return 0; /* missing expression */
296 if (n == LPAREN) {
297 if ((nn = t_lex(*++t_wp)) == RPAREN)
298 return 0; /* missing expression */
299 res = oexpr(nn);
300 if (t_lex(*++t_wp) != RPAREN)
301 syntax(NULL, "closing paren expected");
302 return res;
303 }
304 if (t_wp_op && t_wp_op->op_type == UNOP) {
305 /* unary expression */
306 if (*++t_wp == NULL)
307 syntax(t_wp_op->op_text, "argument expected");
308 switch (n) {
309 case STREZ:
310 return strlen(*t_wp) == 0;
311 case STRNZ:
312 return strlen(*t_wp) != 0;
313 case FILTT:
314 return isatty(getn(*t_wp));
315 default:
316 return filstat(*t_wp, n);
317 }
318 }
319
320 if (t_lex(t_wp[1]), t_wp_op && t_wp_op->op_type == BINOP) {
321 return binop();
322 }
323
324 return strlen(*t_wp) > 0;
325}
326
327static int
328binop(void)
329{
330 const char *opnd1, *opnd2;
331 struct t_op const *op;
332
333 opnd1 = *t_wp;
334 (void) t_lex(*++t_wp);
335 op = t_wp_op;
336
337 if ((opnd2 = *++t_wp) == NULL)
338 syntax(op->op_text, "argument expected");
339
340 switch (op->op_num) {
341 case STREQ:
342 return strcmp(opnd1, opnd2) == 0;
343 case STRNE:
344 return strcmp(opnd1, opnd2) != 0;
345 case STRLT:
346 return strcmp(opnd1, opnd2) < 0;
347 case STRGT:
348 return strcmp(opnd1, opnd2) > 0;
349 case INTEQ:
350 return getn(opnd1) == getn(opnd2);
351 case INTNE:
352 return getn(opnd1) != getn(opnd2);
353 case INTGE:
354 return getn(opnd1) >= getn(opnd2);
355 case INTGT:
356 return getn(opnd1) > getn(opnd2);
357 case INTLE:
358 return getn(opnd1) <= getn(opnd2);
359 case INTLT:
360 return getn(opnd1) < getn(opnd2);
361 case FILNT:
362 return newerf(opnd1, opnd2);
363 case FILOT:
364 return olderf(opnd1, opnd2);
365 case FILEQ:
366 return equalf(opnd1, opnd2);
367 default:
368 abort();
369 /* NOTREACHED */
370 }
371}
372
373/*
374 * The manual, and IEEE POSIX 1003.2, suggests this should check the mode bits,
375 * not use access():
376 *
377 * True shall indicate only that the write flag is on. The file is not
378 * writable on a read-only file system even if this test indicates true.
379 *
380 * Unfortunately IEEE POSIX 1003.1-2001, as quoted in SuSv3, says only:
381 *
382 * True shall indicate that permission to read from file will be granted,
383 * as defined in "File Read, Write, and Creation".
384 *
385 * and that section says:
386 *
387 * When a file is to be read or written, the file shall be opened with an
388 * access mode corresponding to the operation to be performed. If file
389 * access permissions deny access, the requested operation shall fail.
390 *
391 * and of course access permissions are described as one might expect:
392 *
393 * * If a process has the appropriate privilege:
394 *
395 * * If read, write, or directory search permission is requested,
396 * access shall be granted.
397 *
398 * * If execute permission is requested, access shall be granted if
399 * execute permission is granted to at least one user by the file
400 * permission bits or by an alternate access control mechanism;
401 * otherwise, access shall be denied.
402 *
403 * * Otherwise:
404 *
405 * * The file permission bits of a file contain read, write, and
406 * execute/search permissions for the file owner class, file group
407 * class, and file other class.
408 *
409 * * Access shall be granted if an alternate access control mechanism
410 * is not enabled and the requested access permission bit is set for
411 * the class (file owner class, file group class, or file other class)
412 * to which the process belongs, or if an alternate access control
413 * mechanism is enabled and it allows the requested access; otherwise,
414 * access shall be denied.
415 *
416 * and when I first read this I thought: surely we can't go about using
417 * open(O_WRONLY) to try this test! However the POSIX 1003.1-2001 Rationale
418 * section for test does in fact say:
419 *
420 * On historical BSD systems, test -w directory always returned false
421 * because test tried to open the directory for writing, which always
422 * fails.
423 *
424 * and indeed this is in fact true for Seventh Edition UNIX, UNIX 32V, and UNIX
425 * System III, and thus presumably also for BSD up to and including 4.3.
426 *
427 * Secondly I remembered why using open() and/or access() are bogus. They
428 * don't work right for detecting read and write permissions bits when called
429 * by root.
430 *
431 * Interestingly the 'test' in 4.4BSD was closer to correct (as per
432 * 1003.2-1992) and it was implemented efficiently with stat() instead of
433 * open().
434 *
435 * This was apparently broken in NetBSD around about 1994/06/30 when the old
436 * 4.4BSD implementation was replaced with a (arguably much better coded)
437 * implementation derived from pdksh.
438 *
439 * Note that modern pdksh is yet different again, but still not correct, at
440 * least not w.r.t. 1003.2-1992.
441 *
442 * As I think more about it and read more of the related IEEE docs I don't like
443 * that wording about 'test -r' and 'test -w' in 1003.1-2001 at all. I very
444 * much prefer the original wording in 1003.2-1992. It is much more useful,
445 * and so that's what I've implemented.
446 *
447 * (Note that a strictly conforming implementation of 1003.1-2001 is in fact
448 * totally useless for the case in question since its 'test -w' and 'test -r'
449 * can never fail for root for any existing files, i.e. files for which 'test
450 * -e' succeeds.)
451 *
452 * The rationale for 1003.1-2001 suggests that the wording was "clarified" in
453 * 1003.1-2001 to align with the 1003.2b draft. 1003.2b Draft 12 (July 1999),
454 * which is the latest copy I have, does carry the same suggested wording as is
455 * in 1003.1-2001, with its rationale saying:
456 *
457 * This change is a clarification and is the result of interpretation
458 * request PASC 1003.2-92 #23 submitted for IEEE Std 1003.2-1992.
459 *
460 * That interpretation can be found here:
461 *
462 * http://www.pasc.org/interps/unofficial/db/p1003.2/pasc-1003.2-23.html
463 *
464 * Not terribly helpful, unfortunately. I wonder who that fence sitter was.
465 *
466 * Worse, IMVNSHO, I think the authors of 1003.2b-D12 have mis-interpreted the
467 * PASC interpretation and appear to be gone against at least one widely used
468 * implementation (namely 4.4BSD). The problem is that for file access by root
469 * this means that if test '-r' and '-w' are to behave as if open() were called
470 * then there's no way for a shell script running as root to check if a file
471 * has certain access bits set other than by the grotty means of interpreting
472 * the output of 'ls -l'. This was widely considered to be a bug in V7's
473 * "test" and is, I believe, one of the reasons why direct use of access() was
474 * avoided in some more recent implementations!
475 *
476 * I have always interpreted '-r' to match '-w' and '-x' as per the original
477 * wording in 1003.2-1992, not the other way around. I think 1003.2b goes much
478 * too far the wrong way without any valid rationale and that it's best if we
479 * stick with 1003.2-1992 and test the flags, and not mimic the behaviour of
480 * open() since we already know very well how it will work -- existance of the
481 * file is all that matters to open() for root.
482 *
483 * Unfortunately the SVID is no help at all (which is, I guess, partly why
484 * we're in this mess in the first place :-).
485 *
486 * The SysV implementation (at least in the 'test' builtin in /bin/sh) does use
487 * access(name, 2) even though it also goes to much greater lengths for '-x'
488 * matching the 1003.2-1992 definition (which is no doubt where that definition
489 * came from).
490 *
491 * The ksh93 implementation uses access() for '-r' and '-w' if
492 * (euid==uid&&egid==gid), but uses st_mode for '-x' iff running as root.
493 * i.e. it does strictly conform to 1003.1-2001 (and presumably 1003.2b).
494 */
495static int
496test_access(struct stat *sp, mode_t stmode)
497{
498 gid_t *groups;
499 register int n;
500 uid_t euid;
501 int maxgroups;
502
503 /*
504 * I suppose we could use access() if not running as root and if we are
505 * running with ((euid == uid) && (egid == gid)), but we've already
506 * done the stat() so we might as well just test the permissions
507 * directly instead of asking the kernel to do it....
508 */
509 euid = geteuid();
510 if (euid == 0) /* any bit is good enough */
511 stmode = (stmode << 6) | (stmode << 3) | stmode;
512 else if (sp->st_uid == euid)
513 stmode <<= 6;
514 else if (sp->st_gid == getegid())
515 stmode <<= 3;
516 else {
517 /* XXX stolen almost verbatim from ksh93.... */
518 /* on some systems you can be in several groups */
519 if ((maxgroups = getgroups(0, NULL)) <= 0)
520 maxgroups = NGROUPS_MAX; /* pre-POSIX system? */
521 groups = ckmalloc((maxgroups + 1) * sizeof(gid_t));
522 n = getgroups(maxgroups, groups);
523 while (--n >= 0) {
524 if (groups[n] == sp->st_gid) {
525 stmode <<= 3;
526 break;
527 }
528 }
529 free(groups);
530 }
531
532 return sp->st_mode & stmode;
533}
534
535static int
536filstat(char *nm, enum token mode)
537{
538 struct stat s;
539
540 if (mode == FILSYM ? lstat(nm, &s) : stat(nm, &s))
541 return 0;
542
543 switch (mode) {
544 case FILRD:
545 return test_access(&s, S_IROTH);
546 case FILWR:
547 return test_access(&s, S_IWOTH);
548 case FILEX:
549 return test_access(&s, S_IXOTH);
550 case FILEXIST:
551 return 1; /* the successful lstat()/stat() is good enough */
552 case FILREG:
553 return S_ISREG(s.st_mode);
554 case FILDIR:
555 return S_ISDIR(s.st_mode);
556 case FILCDEV:
557 return S_ISCHR(s.st_mode);
558 case FILBDEV:
559 return S_ISBLK(s.st_mode);
560 case FILFIFO:
561 return S_ISFIFO(s.st_mode);
562 case FILSOCK:
563 return S_ISSOCK(s.st_mode);
564 case FILSYM:
565 return S_ISLNK(s.st_mode);
566 case FILSUID:
567 return (s.st_mode & S_ISUID) != 0;
568 case FILSGID:
569 return (s.st_mode & S_ISGID) != 0;
570 case FILSTCK:
571 return (s.st_mode & S_ISVTX) != 0;
572 case FILGZ:
573 return s.st_size > (off_t)0;
574 case FILUID:
575 return s.st_uid == geteuid();
576 case FILGID:
577 return s.st_gid == getegid();
578 default:
579 return 1;
580 }
581}
582
583#define VTOC(x) (const unsigned char *)((const struct t_op *)x)->op_text
584
585static int
586compare1(const void *va, const void *vb)
587{
588 const unsigned char *a = va;
589 const unsigned char *b = VTOC(vb);
590
591 return a[0] - b[0];
592}
593
594static int
595compare2(const void *va, const void *vb)
596{
597 const unsigned char *a = va;
598 const unsigned char *b = VTOC(vb);
599 int z = a[0] - b[0];
600
601 return z ? z : (a[1] - b[1]);
602}
603
604static struct t_op const *
605findop(const char *s)
606{
607 if (s[0] == '-') {
608 if (s[1] == '\0')
609 return NULL;
610 if (s[2] == '\0')
611 return bsearch(s + 1, mop2, __arraycount(mop2),
612 sizeof(*mop2), compare1);
613 else if (s[3] != '\0')
614 return NULL;
615 else
616 return bsearch(s + 1, mop3, __arraycount(mop3),
617 sizeof(*mop3), compare2);
618 } else {
619 if (s[1] == '\0')
620 return bsearch(s, cop, __arraycount(cop), sizeof(*cop),
621 compare1);
622 else if (strcmp(s, cop2[0].op_text) == 0)
623 return cop2;
624 else
625 return NULL;
626 }
627}
628
629static enum token
630t_lex(char *s)
631{
632 struct t_op const *op;
633
634 if (s == NULL) {
635 t_wp_op = NULL;
636 return EOI;
637 }
638
639 if ((op = findop(s)) != NULL) {
640 if (!((op->op_type == UNOP && isoperand()) ||
641 (op->op_num == LPAREN && *(t_wp+1) == 0))) {
642 t_wp_op = op;
643 return op->op_num;
644 }
645 }
646 t_wp_op = NULL;
647 return OPERAND;
648}
649
650static int
651isoperand(void)
652{
653 struct t_op const *op;
654 char *s, *t;
655
656 if ((s = *(t_wp+1)) == 0)
657 return 1;
658 if ((t = *(t_wp+2)) == 0)
659 return 0;
660 if ((op = findop(s)) != NULL)
661 return op->op_type == BINOP && (t[0] != ')' || t[1] != '\0');
662 return 0;
663}
664
665/* atoi with error detection */
666static int
667getn(const char *s)
668{
669 char *p;
670 long r;
671
672 errno = 0;
673 r = strtol(s, &p, 10);
674
675 if (errno != 0)
676 error("%s: out of range", s);
677
678 while (isspace((unsigned char)*p))
679 p++;
680
681 if (*p)
682 error("%s: bad number", s);
683
684 return (int) r;
685}
686
687static int
688newerf(const char *f1, const char *f2)
689{
690 struct stat b1, b2;
691
692 return (stat(f1, &b1) == 0 &&
693 stat(f2, &b2) == 0 &&
694 b1.st_mtime > b2.st_mtime);
695}
696
697static int
698olderf(const char *f1, const char *f2)
699{
700 struct stat b1, b2;
701
702 return (stat(f1, &b1) == 0 &&
703 stat(f2, &b2) == 0 &&
704 b1.st_mtime < b2.st_mtime);
705}
706
707static int
708equalf(const char *f1, const char *f2)
709{
710 struct stat b1, b2;
711
712 return (stat(f1, &b1) == 0 &&
713 stat(f2, &b2) == 0 &&
714 b1.st_dev == b2.st_dev &&
715 b1.st_ino == b2.st_ino);
716}
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